Add initial ATT tosca checker tool

Addressed license headers and copyright owner issues
Addressed project folder name

Issue-ID: MODELING-7
Change-Id: I150784c5871bb6093ff0a6615639088bc2e0c496
Signed-off-by: Serban Jora <jora@research.att.com>

114 files changed, 15807 insertions, 0 deletions

diff --git a/javatoscachecker/checker/pom.xml b/javatoscachecker/checker/pom.xml
new file mode 100644
index 0000000..a408bc6
--- /dev/null
+++ b/javatoscachecker/checker/pom.xml
@@ -0,0 +1,201 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>org.onap.tosca</groupId>
+    <artifactId>checker</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+  </parent>
+  <artifactId>Checker</artifactId>
+  <packaging>jar</packaging>
+  <name>Checker</name>
+
+	<build>
+	    <sourceDirectory>src/main/java</sourceDirectory>
+	    <plugins>
+	      <plugin>
+	        <artifactId>maven-compiler-plugin</artifactId>
+	        <version>3.1</version>
+	        <configuration>
+	          <source>1.8</source>
+	          <target>1.8</target>
+	          <encoding>${project.build.sourceEncoding}</encoding>
+	        </configuration>
+	      </plugin>
+	      <plugin>
+	        <groupId>org.apache.maven.plugins</groupId>
+	        <artifactId>maven-dependency-plugin</artifactId>
+	        <version>2.10</version>
+	        <executions>
+	          <execution>
+	            <id>copy-dependencies</id>
+	            <phase>package</phase>
+	            <goals>
+	              <goal>copy-dependencies</goal>
+	            </goals>
+	            <configuration>
+	              <outputDirectory>${project.build.directory}/deps</outputDirectory>
+	              <overWriteReleases>false</overWriteReleases>
+	              <overWriteSnapshots>false</overWriteSnapshots>
+	              <overWriteIfNewer>true</overWriteIfNewer>
+	            </configuration>
+	          </execution>
+	        </executions>
+	      </plugin>
+      	<plugin>
+        	<groupId>org.codehaus.mojo</groupId>
+	        <artifactId>buildnumber-maven-plugin</artifactId>
+  	      <version>1.4</version>
+    	    <executions>
+      	    <execution>
+        	    <phase>validate</phase>
+          	  <goals>
+            	  <goal>create</goal>
+  	          </goals>
+    	      </execution>
+      	  </executions>
+        	<configuration>
+          	<doCheck>false</doCheck>
+          	<doUpdate>false</doUpdate>
+        	</configuration>
+      	</plugin>
+				<plugin>
+        	<groupId>org.apache.maven.plugins</groupId>
+        	<artifactId>maven-jar-plugin</artifactId>
+        	<version>2.1</version>
+        	<configuration>
+          	<archive>
+            	<manifest>
+              	<addDefaultImplementationEntries>true</addDefaultImplementationEntries>
+            	</manifest>
+            	<manifestEntries>
+              	<Implementation-Build>${buildNumber}</Implementation-Build>
+            	</manifestEntries>
+          	</archive>
+        	</configuration>
+				</plugin>
+	      
+				<plugin>
+        	<groupId>org.apache.maven.plugins</groupId>
+	        <artifactId>maven-assembly-plugin</artifactId>
+  	      <version>2.6</version>
+    	    <configuration>
+      	    <descriptorRefs>
+        	    <descriptorRef>jar-with-dependencies</descriptorRef>
+          	</descriptorRefs>
+	          <archive>
+  	          <manifest>
+    	          <mainClass>org.onap.tosca.checker.Checker</mainClass>
+      	      </manifest>
+							<manifestEntries>
+              	<Implementation-Build>${buildNumber}</Implementation-Build>
+							</manifestEntries>
+        	  </archive>
+  	      </configuration>
+    	    <executions>
+      	    <execution>
+        	    <id>make-assembly</id> <!-- this is used for inheritance merges -->
+          	  <phase>package</phase> <!-- bind to the packaging phase -->
+            	<goals>
+              	<goal>single</goal>
+    	        </goals>
+      	    </execution>
+        	</executions>
+      	</plugin>
+
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-jar-plugin</artifactId>
+        <version>3.0.2</version>
+        <executions>
+          <execution>
+            <goals>
+              <goal>test-jar</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+      	<plugin>
+        	<groupId>org.apache.maven.plugins</groupId>
+        	<artifactId>maven-javadoc-plugin</artifactId>
+        	<version>3.0.0-M1</version>
+        	<configuration>
+          	<doctitle>API for ${project.name} ${project.version}</doctitle>
+          	<windowtitle>API for ${project.name} ${project.version}</windowtitle>
+        	</configuration>
+      	</plugin>
+				<!-- blackduck maven plugin -->
+				<plugin>
+					<groupId>com.blackducksoftware.integration</groupId>
+ 					<artifactId>hub-maven-plugin</artifactId>
+ 					<version>2.0.0</version>
+ 					<inherited>false</inherited>
+ 					<configuration>
+  					<hubProjectName>${project.name}</hubProjectName>
+  					<outputDirectory>${project.basedir}</outputDirectory>
+  					<deployHubBdio>false</deployHubBdio>
+ 					</configuration>
+				 	<executions>
+  					<execution>
+ 						  <id>create-bdio-file</id>
+   						<phase>package</phase>
+   						<goals>
+    						<goal>build-bom</goal>
+   						</goals>
+  					</execution>
+					</executions>
+				</plugin>
+	    </plugins>
+	  </build>
+  <dependencies>
+		<dependency>
+			<groupId>commons-io</groupId>
+			<artifactId>commons-io</artifactId>
+			<version>[2.5,)</version>
+		</dependency>
+		<dependency>
+			<groupId>commons-cli</groupId>
+			<artifactId>commons-cli</artifactId>
+			<version>[1.3,)</version>
+		</dependency>
+		<dependency>
+			<groupId>commons-jxpath</groupId>
+			<artifactId>commons-jxpath</artifactId>
+			<version>[1.3,)</version>
+		</dependency>
+		<dependency>
+			<groupId>commons-lang</groupId>
+			<artifactId>commons-lang</artifactId>
+			<version>[2.6,)</version>
+		</dependency>
+		<dependency>
+			<groupId>com.google.guava</groupId>
+			<artifactId>guava</artifactId>
+			<version>[21.0,)</version>
+		</dependency>
+		<dependency>
+			<groupId>org.yaml</groupId>
+			<artifactId>snakeyaml</artifactId>
+			<version>[1.17,)</version>
+		</dependency>
+		<dependency>
+    	<groupId>com.fasterxml.jackson.core</groupId>
+    	<artifactId>jackson-core</artifactId>
+    	<version>[2.7.5,)</version>
+		</dependency>
+		<dependency>
+    	<groupId>com.fasterxml.jackson.core</groupId>
+    	<artifactId>jackson-databind</artifactId>
+    	<version>[2.7.5,)</version>
+		</dependency>
+		<dependency>
+    	<groupId>org.reflections</groupId>
+    	<artifactId>reflections</artifactId>
+    	<version>[0.9.11,)</version>
+		</dependency>
+		<dependency>
+			<groupId>org.onap.tosca</groupId>
+  	  <artifactId>kwalify</artifactId>
+  	  <version>0.0.1-SNAPSHOT</version>
+   	</dependency>
+  </dependencies>
+</project>
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/CSARRepository.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/CSARRepository.java
new file mode 100644
index 0000000..6375185
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/CSARRepository.java
@@ -0,0 +1,282 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker;
+
+import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+import java.io.Reader;
+import java.io.StringReader;
+import java.io.InputStream;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.InputStreamReader;
+import java.io.BufferedReader;
+
+import java.net.URI;
+import java.net.URL;
+import java.net.MalformedURLException;
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import java.util.Map;
+import java.util.HashMap;
+import java.util.Properties;
+import java.util.Collections;
+
+import java.util.zip.ZipInputStream;
+import java.util.zip.ZipEntry;
+
+import java.util.function.BiFunction;
+
+import org.apache.commons.io.IOUtils;
+
+/**
+ * Handles targets located within the same CSAR file.
+ * This is where the knowledge about the structure of a CSAR file should be placed.
+ * TOSCA 1.0 CSAR archive compliant.
+ */
+public class CSARRepository extends Repository {
+
+
+	private String	metaEntryName = "TOSCA-Metadata/TOSCA.meta";
+		
+	private byte[] 						data;
+	private Properties 				meta = new Properties();
+	private Map<URI, Target> 	entries = null;
+	
+	public CSARRepository(String theName, URI theRoot) throws IOException {
+		super(theName, theRoot);
+		load();
+	}
+
+	private void load() throws IOException {
+		InputStream is = null;
+  	try {
+			is = this.getRoot().toURL().openStream();
+			this.data = IOUtils.toByteArray(is);
+		}
+		finally {
+			if (is != null) {
+				try {
+					is.close();
+				}
+				catch(IOException iox) {}
+			}
+		}
+	}
+
+	//one should read the meta-inf/MANIFEST.MF file before deciding that a file is text
+	private Object processData(BiFunction<ZipEntry,InputStream,Object> theProcessor) {
+
+		ZipInputStream archiveInputStream = new ZipInputStream(new ByteArrayInputStream(this.data));
+		Object result = null;
+		try {
+			ZipEntry archiveEntry = null;
+			while ((archiveEntry = archiveInputStream.getNextEntry()) != null) {
+				result = theProcessor.apply(archiveEntry, archiveInputStream);
+				if (null != result)
+					return result;
+				archiveInputStream.closeEntry();	
+			}	
+		}
+		catch (IOException iox) {
+			log.log(Level.WARNING, "Failed to read archive", iox);
+		}
+		finally {
+			try {
+				archiveInputStream.close();
+			}
+			catch (IOException iox) {
+			}
+		}
+		return result;
+	}
+
+	/* this will be useful when processing new style meta information .. */
+	private Object processMeta() {
+		return
+			processData( (entry,stream) -> {
+				if (!entry.getName().equals(this.metaEntryName))
+					return null;
+
+				return readMeta(stream);
+			});
+	}
+	
+	private Boolean readMeta(InputStream theStream) {
+		BufferedReader reader = null;
+		try {
+			reader = new BufferedReader(new InputStreamReader(theStream, "UTF-8"));
+			this.meta.load(reader);
+			return Boolean.TRUE;
+		}
+		catch(IOException iox) {
+			log.log(Level.WARNING, "Failed to read archive meta entry", iox);
+			return Boolean.FALSE;
+		}	
+		finally {
+			/*
+			if (reader != null) {
+				try {
+					reader.close();
+				}
+				catch (IOException iox) {
+				}
+			}
+			*/
+			//!!Do not close as it is used with processData which does the entry close itself
+		}
+	}			
+
+	/*
+	private Boolean readMeta() {
+		BufferedReader reader = null;
+		try {
+			reader = new BufferedReader(new InputStreamReader(stream, "UTF-8"));
+			String line = null;
+			while ((line = reader.readLine()) != null) {
+				//TODO:
+			}
+			return Boolean.TRUE;
+		}
+		catch (IOException iox) {
+			log.log(Level.WARNING, "Failed to read archive meta entry", iox);
+			return Boolean.FALSE;
+		}
+		finally {
+			if (reader != null) {
+				try {
+					reader.close();
+				}
+				catch (IOException iox) {
+				}
+			}
+			//!!Do not close as it is used with processData which does the entry close itself
+		}
+	}	
+	*/
+
+	private Map<URI,Target> entries() {
+		if (this.entries == null) {
+			this.entries = new HashMap<URI, Target>();
+			processData( (entry,stream) -> { 
+				URI entryURI = this.rootURI.resolve(entry.getName());
+				this.entries.put(entryURI, new CsarTarget(entry.getName(), entryURI)); 
+				
+				if (entry.getName().equals(this.metaEntryName))
+					readMeta(stream);
+
+				return null;
+			});
+		}
+		return this.entries;
+	}
+
+	public Target mainTarget() {
+		return entries().get(rootURI.resolve(this.meta.getProperty("Entry-Definitions")));
+	}
+	
+	public Iterable<Target> targets() {
+		return entries().values();
+	}
+
+	/** */
+	public Target resolve(URI theURI) {
+		return entries().get(theURI);
+	}
+
+	public TargetLocator getTargetLocator() {
+		return new CSARTargetLocator();
+	}
+
+	/**
+	 */
+	private class CSARTargetLocator implements TargetLocator {
+
+		/** */
+		public boolean addSearchPath(URI theURI) {
+			return false;
+		}
+
+		/** */
+		public boolean addSearchPath(String thePath) {
+			return false;
+		}
+
+		/** */
+		public Iterable<URI> searchPaths() {
+			return Collections.singleton(CSARRepository.this.rootURI);
+		}
+	
+		/** */
+		public Target resolve(String theName) {
+			Target t = entries().get(CSARRepository.this.rootURI.resolve(theName));
+			if (t == null) {
+				//fallback: check relative to the main target folder
+				t = entries().get(CSARRepository.this.mainTarget().getLocation().resolve(theName));
+			}
+			return t;
+		}
+	}
+
+	/** */
+	private class CsarTarget extends Target {
+					
+		private String content;
+
+		private CsarTarget(String theName, URI theUri) {
+			super(theName, theUri);
+		}
+
+		private String content() {
+			if (this.content == null) {
+				this.content = (String)processData( (entry,stream) -> {
+					//go over the entries and find the one with a matching name
+					ByteArrayOutputStream out = null;
+					if (entry.getName().equals(getName())) {
+						byte[] buffer = new byte[4096];
+						int len = 0;
+						out = new ByteArrayOutputStream();
+						try {
+							while ((len = stream.read(buffer)) > 0) {
+   							out.write(buffer, 0, len);
+							}
+							log.info(entry.getName() + ": " + out.toString("UTF-8"));
+						}
+						catch (IOException iox) {
+							log.warning("Failed to read entry data: " + iox);
+							return out = null;
+						}
+					}
+					//!!Do not close as it is used with processData which does the entry close itself
+
+					try {
+						return (out != null) ? out.toString("UTF-8") : null;
+					}
+					catch (UnsupportedEncodingException uex) {
+						log.warning("Failed to process entry data as string: " + uex);
+						return "";
+					}
+				});
+			}
+			return this.content;
+		}
+
+		public Reader open() throws IOException {
+			return new StringReader(content());
+		}
+	}
+
+}
+
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Canonicals.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Canonicals.java
new file mode 100644
index 0000000..3c12844
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Canonicals.java
@@ -0,0 +1,200 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker;
+
+import java.util.List;
+import java.util.LinkedList;
+import java.util.Map;
+import java.util.HashMap;
+import java.util.TreeMap;
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import java.util.regex.Pattern;
+import java.util.regex.Matcher;
+
+import kwalify.Validator;
+import kwalify.Rule;
+import kwalify.Types;
+
+import com.google.common.collect.Table;
+import com.google.common.collect.HashBasedTable;
+
+import org.apache.commons.jxpath.JXPathContext;
+import org.apache.commons.jxpath.JXPathException;
+
+import org.onap.tosca.checker.annotations.Validates;
+
+/**
+ * Constructs and collects the canonical form during the validation step (syntax check) based on the short form
+ * indicator from the grammar specification.
+ * The TOSCA spec indicates a 'short' form for most of the constructs but we want checking to be able to work on
+ * the canonical form and not to have to handle the short form explicitly. Additionally tis makes for a simpler 
+ * grammar specification. 
+ */
+public class Canonicals {
+
+	private Logger    					log = Logger.getLogger("com.att.research.asc.chcker.Canonicals");
+	
+	private Table<Target, String, Object> canonicals = null; //HashBasedTable.create();
+
+	@Validates(rule="", timing=Validates.Timing.pre)
+  public boolean pre_validate_short_form(
+			Object theValue, Rule theRule, Validator.ValidationContext theContext) {
+
+		String hint = theRule.getShort();
+		if (theValue != null &&
+				hint != null) {
+
+			log.finer("Attempting canonical at " + theContext.getPath() + ", rule " + theRule.getName());
+
+		  Object canonical = null;
+			//if the canonical form requires a collection
+			if (Types.isCollectionType(theRule.getType())) {
+				//and the actual value isn't one
+				if( !(theValue instanceof Map || theValue instanceof List)) {
+					//used to use singleton map/list here (was good for catching errors)
+					//but there is the possibility of short forms within short forms so
+					//the created canonicals need to accomodate other values.
+					if (Types.isMapType(theRule.getType())) {
+						canonical = new HashMap();
+						((Map)canonical).put(hint, theValue);
+					}
+					else {
+						//the hint is irrelevant here but we should impose a value when the target is a list
+						canonical = new LinkedList();
+						((List)canonical).add(theValue);
+					}
+       	}
+				else {
+					//we can accomodate:
+					// map to list of map transformation
+					if (!Types.isMapType(theRule.getType()) /* a seq */ &&
+							theValue instanceof Map) {
+						canonical = new LinkedList();
+						((List)canonical).add(theValue);	
+					}
+					else {
+     				log.fine("Grammar for rule " + theRule.getName() + " (at " + theContext.getPath() + ") would require unsupported short form transformation: " + theValue.getClass() + " to " + theRule.getType());
+						return false;		
+					}
+				}
+ 
+				int errc = theContext.errorCount();
+				//validateRule(canonical, rule, context);
+				if (errc != theContext.errorCount()) {
+					//this would indicate that the grammar is not well specified
+      		log.warning("Short notation for " + theRule.getName() + " through " + hint + " at " + theContext.getPath() + " failed validation");
+				}
+				else {
+       		log.finer("Short notation for " + theRule.getName() + " through " + hint + " at " + theContext.getPath() + " passed validation. Canonical form is " + canonical);
+
+					if (this.canonicals != null)
+						this.canonicals.put(
+										((Checker.TOSCAValidator)theContext.getValidator()).getTarget(),
+										theContext.getPath(), canonical);
+					else {
+						applyCanonical(
+										((Checker.TOSCAValidator)theContext.getValidator()).getTarget().getTarget(),
+										theContext.getPath(), canonical);
+					}
+					return true;
+				}
+			}
+			else {
+      	log.info("Grammar for rule " + theRule.getName() + " (at " + theContext.getPath() + ") would require unsupported short form transformation: " + theValue.getClass() + " to " + theRule.getType());
+				return false;
+			}
+		}
+		return false;
+	}
+
+
+	protected Object applyCanonical(Object theTarget,
+																	String thePath,
+															  	Object theCanonical) {
+
+		//Object canonical = theCanonicals.get(thePath);
+		//if (canonical != null) {
+			String path = patchWhitespaces(
+											patchIndexes(thePath));
+	    try {
+		  	JXPathContext.newContext(theTarget).setValue(path, theCanonical);
+				log.finer("Applied canonical form at: " + path);
+
+		//		if (doRemove)
+		//			theCanonicals.remove(thePath);
+			}
+			catch (JXPathException jxpx) {
+				log.log(Level.WARNING, "Failed to apply canonical to " + theTarget, jxpx);
+			}
+		//}
+		return theCanonical;
+	}
+
+	public void applyCanonicals(Target theTarget) {
+    
+		if (this.canonicals == null) {
+			return;
+	  }
+
+		Map<String, Object> targetCanonicals = this.canonicals.row(theTarget);
+		if (targetCanonicals != null) {
+	    log.finest("applying canonicals: " + targetCanonicals);
+			for(Map.Entry<String, Object> canonicalEntry: targetCanonicals.entrySet()) {
+				applyCanonical(theTarget.getTarget(), canonicalEntry.getKey(), canonicalEntry.getValue());
+			}
+		}
+	}
+
+  /** Given that we remembered the canonical forms that were needed during
+	 * validation to replace the short forms we can apply them to the target
+	 * yaml.
+	 * We take advantage here of the fact that the context path maintained 
+	 * during validation is compatible with (j)xpath, with the exception of
+	 * sequence/array indentation ..
+	 */
+
+  private Pattern indexPattern = Pattern.compile("/\\p{Digit}+"),
+									spacePattern = Pattern.compile("\\s");
+
+  private String patchIndexes(CharSequence thePath) {
+  	Matcher m = indexPattern.matcher(thePath);
+		StringBuffer path = new StringBuffer();
+		while (m.find()) {
+			String index = m.group();
+      index = "[" + (Integer.valueOf(index.substring(1)).intValue() + 1) + "]";
+			m.appendReplacement(path, m.quoteReplacement(index));
+		}
+		m.appendTail(path);
+		return path.toString();
+	}
+ 
+ 
+	private String patchWhitespaces(String thePath) {
+		String[] elems = thePath.split("/");
+		StringBuffer path = new StringBuffer();
+		for (int i = 0; i < elems.length; i++) {
+			if (spacePattern.matcher(elems[i]).find())
+				path.append("[@name='")
+						.append(elems[i])
+						.append("']");
+			else
+				path.append("/")
+						.append(elems[i]);
+		}
+		return path.toString();
+	}
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Catalog.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Catalog.java
new file mode 100644
index 0000000..35d0d1c
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Catalog.java
@@ -0,0 +1,459 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker;
+
+import java.util.Iterator;
+import java.util.Collection;
+import java.util.Comparator;
+import java.util.Set;
+import java.util.Map;
+import java.util.List;
+import java.util.EnumMap;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.ArrayList;
+import java.util.Collections;
+
+import java.util.stream.Collectors;
+
+import java.net.URI;
+
+import com.google.common.base.Predicate;
+import com.google.common.base.Function;
+import com.google.common.collect.Iterators;
+import com.google.common.collect.Table;
+import com.google.common.collect.HashBasedTable;
+
+/*
+ * Oddball: tracking inputs as data templates could be seen as rather
+ * odd but we see them as instances of data types, in the same way node 
+ * templates are instances of node types.
+ */
+public class Catalog {
+
+   /* Type hierarchies are stored as maps from a type name to its definition
+    * Not the best but easy to follow hierarchies towards their root ..
+    */
+   private EnumMap<Construct, Map<String,Map>> types =
+                            new EnumMap<Construct, Map<String,Map>>(Construct.class);
+	 /* track templates: we track templates (tye instances) first per target then per contruct.
+   	* This allows us to share the catalog among multiple templates sharign the same type set
+    */
+   private Map<Target, EnumMap<Construct, Map<String,Map>>> templates =
+                            new HashMap<Target, EnumMap<Construct, Map<String,Map>>>();
+
+	private Catalog parent;
+
+	public Catalog(Catalog theParent) {
+		this.parent = theParent;
+		/* there are no requirement types, they are the same as capability types */
+ 		types.put(Construct.Data, new LinkedHashMap<String, Map>());
+ 		types.put(Construct.Capability, new LinkedHashMap<String, Map>());
+ 		types.put(Construct.Relationship, new LinkedHashMap<String, Map>());
+ 		types.put(Construct.Artifact, new LinkedHashMap<String, Map>());
+		types.put(Construct.Interface, new LinkedHashMap<String, Map>());
+		types.put(Construct.Node, new LinkedHashMap<String, Map>());
+		types.put(Construct.Group, new LinkedHashMap<String, Map>());
+		types.put(Construct.Policy, new LinkedHashMap<String, Map>());
+     
+	}
+	
+	public Catalog() {
+		this(null);
+	}
+
+	public boolean addType(Construct theConstruct, String theName, Map theDef) {
+		if (hasType(theConstruct, theName)) {
+			return false;
+		}
+		getConstructTypes(theConstruct).put(theName, theDef);
+		return true;
+  }
+
+	public Map getTypeDefinition(Construct theConstruct, String theName) {
+		Map<String, Map> constructTypes = getConstructTypes(theConstruct);
+		Map typeDef = constructTypes.get(theName);
+		if (typeDef == null && this.parent != null) {
+			return this.parent.getTypeDefinition(theConstruct, theName);
+		}
+		return typeDef;
+	}
+
+  public boolean hasType(Construct theConstruct, String theName) {
+		Map<String, Map> constructTypes = getConstructTypes(theConstruct);
+		boolean res = constructTypes.containsKey(theName);
+		if (!res && this.parent != null) {
+			res = this.parent.hasType(theConstruct, theName);
+		}
+		return res;
+	}
+
+	public Map<String, Map> getConstructTypes(Construct theConstruct) {
+		Map<String, Map> constructTypes = this.types.get(theConstruct);
+		if (null == constructTypes) {
+			throw new RuntimeException("Something worse is cooking here!",
+							new CatalogException("No types for construct " + theConstruct));
+		}
+		return constructTypes;
+	}
+
+	protected Iterator<Map.Entry<String,Map>> 
+											typesIterator(Construct theConstruct) {
+ 		List<Map.Entry<String,Map>> constructTypes =
+												new ArrayList<Map.Entry<String,Map>>(
+													this.types.get(theConstruct).entrySet());
+		Collections.reverse(constructTypes);
+		return (this.parent == null)
+							? constructTypes.iterator()
+							: Iterators.concat(constructTypes.iterator(),
+																 this.parent.typesIterator(theConstruct));
+	}
+
+   /* this will iterate through the type hierarchy for the given type, included.
+    */
+	public Iterator<Map.Entry<String,Map>>
+										hierarchy(Construct theConstruct, final String theName) {
+		return Iterators.filter(typesIterator(theConstruct),
+                             new Predicate<Map.Entry<String,Map>>() {
+                               Object next = theName;
+                               public boolean apply(Map.Entry<String,Map> theEntry) {
+                                 if (next != null && next.equals(theEntry.getKey())) {
+                                   next = theEntry.getValue().get("derived_from");
+                                   return true;
+                                 }
+                                 else
+                                   return false;
+                               }
+                             });
+   }
+   
+	 public boolean isDerivedFrom(Construct theConstruct, String theType, String theBaseType) {
+
+		Iterator<Map.Entry<String,Map>> hierachyIterator = 
+																					hierarchy(theConstruct, theType);
+		while (hierachyIterator.hasNext())	{
+			Map.Entry<String,Map> typeDef = hierachyIterator.next();
+
+			if (typeDef.getKey().equals(theBaseType)) {
+				return true;
+			}
+		}
+		return  false;
+	 }
+
+	/* We go over the type hierarchy and retain only an iterator over the
+	 * elements of the given facet for each type in the hierarchy.
+	 * We concatenate these iterators and filter out duplicates.
+	 * TODO: cannot just filter out duplicates - a redefinition can refine the one in the base construct so we
+	 * should merge them!
+	 */
+	public Iterator<Map.Entry> facets(Construct theConstruct,
+																		final Facet theFacet,
+																		final String theName) {
+		return
+			Iterators.filter(	
+				Iterators.concat(
+					Iterators.transform(
+						hierarchy(theConstruct, theName),
+						new Function<Map.Entry<String,Map>, Iterator<Map.Entry>>() {
+							public Iterator<Map.Entry> apply(Map.Entry<String,Map> theEntry) {
+								Map m = (Map)theEntry.getValue().get(theFacet.name());
+								return m == null
+													? Collections.emptyIterator()
+													: m.entrySet().iterator();
+							}
+						}							
+					)
+				),
+        new Predicate<Map.Entry>() {
+					Set insts = new HashSet();
+					public boolean apply(Map.Entry theEntry) {
+						return !insts.contains(theEntry.getKey());
+					}
+				}	
+			);
+	}
+	
+	//no need to specify a construct, only nodes can have requirements
+	public Iterator<Map.Entry> requirements(final String theName) {
+		return
+			Iterators.concat(
+				Iterators.transform(
+					hierarchy(Construct.Node, theName),
+					new Function<Map.Entry<String,Map>, Iterator<Map.Entry>>() {
+						public Iterator<Map.Entry> apply(Map.Entry<String,Map> theEntry) {
+							List<Map> l = (List<Map>)theEntry.getValue().get("requirements");
+							return l == null
+												? Collections.emptyIterator()
+												: Iterators.concat(
+														Iterators.transform(
+															l.iterator(),
+															new Function<Map, Iterator<Map.Entry>> () {
+																public Iterator<Map.Entry> apply(Map theEntry) {
+																	return theEntry.entrySet().iterator();
+																}
+															}
+														)	
+													);
+							}
+						}							
+					)
+				);
+	}
+
+	/* Example: find the definition of property 'port' of the node type 
+	 * tosca.nodes.Database (properties being a facet of the node construct)
+	 *
+	 * Note: the definition of a facet is cumulative, i.e. more specialized
+	 * definitions contribute (by overwriting) to the 
+	 */
+	public Map getFacetDefinition(Construct theConstruct,
+																String theConstructTypeName,
+																Facet theFacet,
+																String theName) {
+		Map def = null;
+		Iterator<Map.Entry<String,Map>> ti = hierarchy(theConstruct, theConstructTypeName);
+		while (ti.hasNext()) {
+			//this is where requirements would yield a List ..
+			Map<String,Map> fset = (Map<String,Map>)
+															//theFacet.iterator(
+														ti.next().getValue().get(theFacet.name());
+			if (fset != null) {
+				def = def == null ? fset.get(theName)
+													: mergeDefinitions(def, fset.get(theName));
+			}
+		}
+		return def;
+	}
+
+	public Map getRequirementDefinition(Construct theConstruct,
+																			String theConstructTypeName,
+																			String theName) {
+		Iterator<Map.Entry<String,Map>> ti = hierarchy(theConstruct, theConstructTypeName);
+		while (ti.hasNext()) {
+			//this is where requirements yield a List ..
+			List<Map> reqs = (List<Map>)
+																ti.next().getValue().get("requirements");
+			for (Map req: reqs) {
+				Map.Entry reqe = (Map.Entry)req.entrySet().iterator().next();
+				if (theName.equals(reqe.getKey())) {
+					return (Map)reqe.getValue();
+				}
+			}
+		}
+		return null;
+	}
+
+  /* */
+  private EnumMap<Construct,Map<String,Map>> getTemplates(Target theTarget) {
+  	EnumMap<Construct, Map<String,Map>> targetTemplates = templates.get(theTarget);
+		if (targetTemplates == null) {
+			targetTemplates = new EnumMap<Construct,Map<String,Map>>(Construct.class);
+			targetTemplates.put(Construct.Data, new LinkedHashMap<String, Map>());
+			targetTemplates.put(Construct.Relationship, new LinkedHashMap<String, Map>());
+			targetTemplates.put(Construct.Node, new LinkedHashMap<String, Map>());
+			targetTemplates.put(Construct.Group, new LinkedHashMap<String, Map>());
+			targetTemplates.put(Construct.Policy, new LinkedHashMap<String, Map>());
+
+			templates.put(theTarget, targetTemplates);
+		}
+		return targetTemplates;
+	}
+
+	public Map<String,Map> getTargetTemplates(Target theTarget, Construct theConstruct) {
+		return getTemplates(theTarget).get(theConstruct);
+	}
+
+	public void addTemplate(Target theTarget, Construct theConstruct, String theName, Map theDef) 
+	 																								throws CatalogException {
+  	Map<String, Map> constructTemplates = getTargetTemplates(theTarget, theConstruct);
+		if (null == constructTemplates) {
+      throw new CatalogException("No such thing as " + theConstruct + " templates");
+		}
+    if (constructTemplates.containsKey(theName)) {
+      throw new CatalogException(theConstruct + " template '" + theName + "' re-declaration");
+    }
+    constructTemplates.put(theName, theDef);
+  }
+
+  public boolean hasTemplate(Target theTarget, Construct theConstruct, String theName) {
+    Map<String, Map> constructTemplates = getTargetTemplates(theTarget, theConstruct);
+    return constructTemplates != null && 
+	        constructTemplates.containsKey(theName);
+  }
+
+  public Map getTemplate(Target theTarget, Construct theConstruct, String theName) {
+    Map<String, Map> constructTemplates = getTargetTemplates(theTarget, theConstruct);
+    if (constructTemplates != null)
+		 	return constructTemplates.get(theName);
+		else
+			return null;
+  }
+
+	public static Map mergeDefinitions(Map theAggregate, Map theIncrement) {
+		if (theIncrement == null)
+			return theAggregate;
+
+		for(Map.Entry e: (Set<Map.Entry>)theIncrement.entrySet()) {
+			theAggregate.putIfAbsent(e.getKey(), e.getValue());
+		}
+		return theAggregate;
+	}
+
+  /* tracks imports, i.e.targets */
+ 	private LinkedHashMap<URI, Target> targets = 
+	 													new LinkedHashMap<URI, Target>();
+	/* tracks dependencies between targets, i.e. the 'adjency' matrix defined by
+	 * the 'import' relationship */
+	private Table<Target,Target,Boolean> imports = HashBasedTable.create();
+
+
+	/*
+   * theParent contains an 'include/import' statement pointing to the Target
+   */
+	public boolean addTarget(Target theTarget, Target theParent) {
+		boolean cataloged = hasTarget(theTarget.getLocation());
+	
+		if(!cataloged) {
+			 targets.put(theTarget.getLocation(), theTarget);
+		}
+
+		if (theParent != null) {
+			imports.put(theParent, theTarget, Boolean.TRUE);
+		}
+
+		return !cataloged;
+	}
+
+	public boolean hasTarget(URI theLocation) {
+		return this.targets.containsKey(theLocation) ? true
+																								 : this.parent != null ? this.parent.hasTarget(theLocation)
+																																			 : false;
+	}
+
+	public Target getTarget(URI theLocation) {
+		Target t = this.targets.get(theLocation);
+		if (t == null && this.parent != null) {
+			t = this.parent.getTarget(theLocation);
+		}
+		return t;
+	}
+
+	public Collection<Target> targets() {
+		return targets.values();
+	}
+
+	/* Targets that no other targets depend on */
+	public Collection<Target> topTargets() {
+		return targets.values()
+						.stream()
+							.filter(t -> !imports.containsColumn(t))
+							.collect(Collectors.toList());
+							
+	}
+	
+	public String importString(Target theTarget) {
+		return importString(theTarget, "  ");
+	}
+
+	private String importString(Target theTarget, String thePrefix) {
+		StringBuilder sb = new StringBuilder("");
+		Map<Target,Boolean> parents = imports.column(theTarget);
+		if (parents != null) {
+			for (Target p: parents.keySet()) {
+				sb.append(thePrefix)
+					.append("from ")
+				  .append(p.getLocation())
+					.append("\n")
+					.append(importString(p, thePrefix + "  "));
+			}
+			//we only keep the positive relationships
+		}
+		return sb.toString();
+	}
+
+	/* */
+	private class TargetComparator implements Comparator<Target> {
+	
+		/* @return 1 if there is a dependency path from TargetOne to TargetTwo, -1 otherwise  */
+		public int compare(Target theTargetOne, Target theTargetTwo) {
+			if (hasPath(theTargetTwo, theTargetOne))
+				return -1;
+
+			if (hasPath(theTargetOne, theTargetTwo))
+				return 1;
+
+			return 0;
+		}
+
+		public boolean hasPath(Target theStart, Target theEnd) {
+			Map<Target,Boolean> deps = imports.row(theStart);
+			if (deps.containsKey(theEnd))
+				return true;
+			for (Target dep: deps.keySet()) {
+				if (hasPath(dep, theEnd))
+					return true;
+			}
+			return false;
+		}
+	}
+
+	public Collection<Target> sortedTargets() {
+		List keys = new ArrayList(this.targets.values());
+		Collections.sort(keys, new TargetComparator());
+		return keys;		
+	}
+
+	public static void main(String[] theArgs) throws Exception {
+
+		Catalog cat = new Catalog();
+
+		Target a = new Target("a", new URI("a")),
+				b = new Target("b", new URI("b")),
+				c = new Target("c", new URI("c")),
+				d = new Target("d", new URI("d"));
+
+		cat.addTarget(a, null);
+		cat.addTarget(b, null);
+		cat.addTarget(c, null);
+		cat.addTarget(d, null);
+
+		cat.addTarget(b, c);
+		cat.addTarget(a, c);
+		cat.addTarget(c, d);
+		cat.addTarget(a, b);
+
+		//System.out.println(cat.importString(c));
+		for (Target t: cat.sortedTargets())
+			System.out.println(t);
+
+		Catalog root = new Catalog();
+		root.addType(Construct.Node, "_a", Collections.emptyMap());
+		root.addType(Construct.Node, "__a", Collections.singletonMap("derived_from", "_a"));
+		root.addType(Construct.Node, "___a", Collections.singletonMap("derived_from", "_a"));
+
+		Catalog base = new Catalog(root);
+		base.addType(Construct.Node, "_b", Collections.singletonMap("derived_from", "__a"));
+		base.addType(Construct.Node, "__b", Collections.singletonMap("derived_from", "_b"));
+		base.addType(Construct.Node, "__b_", Collections.singletonMap("derived_from", "_a"));
+
+		if (theArgs.length > 0) {
+			Iterator<Map.Entry<String, Map>> ti = 
+																	base.hierarchy(Construct.Node, theArgs[0]);
+			while (ti.hasNext()) {
+				System.out.println("> " + ti.next().getKey());
+			}
+		}
+	}
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/CatalogException.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/CatalogException.java
new file mode 100644
index 0000000..1f6b602
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/CatalogException.java
@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker;
+
+
+/**
+ * 
+ */
+public class CatalogException extends Exception {
+
+  public CatalogException(String theMsg, Throwable theCause) {
+    super(theMsg, theCause);
+  }
+
+  public CatalogException(String theMsg) {
+    super(theMsg);
+  }
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Checker.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Checker.java
new file mode 100644
index 0000000..9991c86
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Checker.java
@@ -0,0 +1,3661 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker;
+
+import java.lang.reflect.Method;
+import java.lang.reflect.InvocationTargetException;
+
+import java.io.File;
+import java.io.InputStream;
+import java.io.FileInputStream;
+import java.io.Reader;
+import java.io.FileReader;
+import java.io.InputStreamReader;
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.FileNotFoundException;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.net.MalformedURLException;
+
+import java.util.HashMap;
+import java.util.TreeMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.ListIterator;
+import java.util.Map;
+import java.util.EnumMap;
+import java.util.List;
+import java.util.LinkedList;
+import java.util.ArrayList;
+import java.util.Set;
+import java.util.Properties;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Arrays;
+import java.util.MissingResourceException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.regex.Pattern;
+import java.util.regex.Matcher;
+import java.util.stream.Collectors;
+
+import javax.naming.CompositeName;
+import javax.naming.InvalidNameException;
+
+import org.yaml.snakeyaml.Yaml;
+
+import com.google.common.collect.Maps;
+import com.google.common.collect.MapDifference;
+import com.google.common.reflect.Invokable;
+
+import com.google.common.io.CharStreams;
+
+import com.google.common.collect.Table;
+import com.google.common.collect.HashBasedTable;
+
+import kwalify.YamlParser;
+import kwalify.Validator;
+import kwalify.Rule;
+import kwalify.Types;
+import kwalify.SchemaException;
+import kwalify.SyntaxException;
+import kwalify.ValidationException;
+
+import org.apache.commons.jxpath.JXPathContext;
+import org.apache.commons.jxpath.JXPathException;
+
+import org.apache.commons.lang.reflect.ConstructorUtils;
+
+import org.reflections.Reflections;
+import org.reflections.util.FilterBuilder;
+import org.reflections.util.ConfigurationBuilder;
+import org.reflections.scanners.TypeAnnotationsScanner;
+import org.reflections.scanners.SubTypesScanner; 
+import org.reflections.scanners.MethodAnnotationsScanner;
+import org.reflections.adapters.JavaReflectionAdapter;
+
+import org.onap.tosca.checker.annotations.Checks;
+import org.onap.tosca.checker.annotations.Catalogs;
+import org.onap.tosca.checker.annotations.Validates;
+
+import static org.onap.tosca.checker.Messages.Message;
+
+
+/*
+ * To consider: model consistency checking happens now along with validation
+ * (is implemented as part of the validation hooks). It might be better to
+ * separate the 2 stages and perform all the consistency checking once 
+ * validation is completed.
+ */
+public class Checker {
+
+
+  public static void main(String[] theArgs) {
+
+    if (theArgs.length == 0) {
+      System.err.println("checker resource_to_validate [processor]*");
+      return;
+    }
+
+		try {
+			Catalog cat = Checker.check(new File(theArgs[0]));
+
+			for (Target t: cat.targets()) {
+				System.err.println(t.getLocation() + "\n" + cat.importString(t) + "\n" + t.getReport());
+			}
+
+			for (Target t: cat.sortedTargets()) {
+				System.out.println(t);
+			}
+
+		}
+		catch (Exception x) {
+			x.printStackTrace();
+		}
+  }
+
+
+  private Target   						target = null; //what we're validating at the moment
+	private	Map<String, Target>	grammars = new HashMap<String, Target>(); //grammars for the different tosca versions
+
+	private CheckerConfiguration config = new CheckerConfiguration();	
+	private Catalog   		catalog;
+	private	TargetLocator	locator = new CommonLocator();
+
+	private Table<String, Method, Object> handlers = HashBasedTable.create();
+	private Messages											messages;
+	private Logger    log = Logger.getLogger(Checker.class.getName());
+
+	private static String[] EMPTY_STRING_ARRAY = new String[0];
+
+
+  public Checker() throws CheckerException {
+    loadGrammars();
+		loadAnnotations();
+		messages = new Messages();
+  }
+
+	/* Need a proper way to indicate where the grammars are and how they should be identified
+	 */
+	private final	String[] grammarFiles = new String[] {"tosca/tosca_simple_yaml_1_0.grammar",
+																											"tosca/tosca_simple_yaml_1_1.grammar"};	
+	private void loadGrammars() throws CheckerException {
+
+		for (String grammarFile: grammarFiles) {
+			Target grammarTarget = this.locator.resolve(grammarFile);
+			if (grammarTarget == null) {
+				log.warning("Failed to locate grammar " + grammarFile);
+				continue;
+			}
+
+    	parseTarget(grammarTarget);
+			if (grammarTarget.getReport().hasErrors()) {
+				log.warning("Invalid grammar " + grammarFile + ": " + grammarTarget.getReport().toString());
+				continue;
+			}
+
+			List versions = null;
+			try {
+				versions = (List)
+										((Map)
+											((Map)
+												((Map)grammarTarget.getTarget())
+													.get("mapping"))
+														.get("tosca_definitions_version"))
+															.get("enum");
+			}
+			catch (Exception x) {
+				log.warning("Invalid grammar " + grammarFile + ": cannot locate tosca_definitions_versions");
+			}
+			if (versions == null || versions.isEmpty()) {
+				log.warning("Invalid grammar " + grammarFile + ": no tosca_definitions_versions specified");
+				continue;
+			}
+
+			for (Object version: versions) {
+				this.grammars.put(version.toString(), grammarTarget);
+			}
+		}
+
+		log.finer("Loaded grammars: " + this.grammars);
+	}
+
+	private void loadAnnotations() throws CheckerException {
+
+		Reflections				 reflections = new Reflections(
+																			new ConfigurationBuilder()
+																						.forPackages("org.onap.tosca")
+																						.filterInputsBy(new FilterBuilder()
+																															.include(".*\\.class")
+																														)
+																						.setScanners(new TypeAnnotationsScanner(),
+																												 new SubTypesScanner(),
+																												 new MethodAnnotationsScanner())
+																						.setExpandSuperTypes(false)
+																						//.setMetadataAdapter(new JavaReflectionAdapter())
+																				);
+
+		Map<Class, Object> refs = new HashMap<Class, Object>();
+		Set<Method> 			 methods = null; 
+		
+		//very similar but annotatons cannot be handled in a more 'generic' manner
+
+		methods = reflections.getMethodsAnnotatedWith(Checks.class);
+		for (Method method: methods) {
+			handlers.put("checks:" + method.getAnnotation(Checks.class).path(),
+									 method,
+									 refs.computeIfAbsent(method.getDeclaringClass(),	type -> newInstance(type))); 
+		}
+			
+		methods = reflections.getMethodsAnnotatedWith(Catalogs.class);
+		for (Method method: methods) {
+			handlers.put("catalogs:" + method.getAnnotation(Catalogs.class).path(),
+								   method,
+								   refs.computeIfAbsent(method.getDeclaringClass(),	type -> newInstance(type)));
+		}
+		
+		methods = reflections.getMethodsAnnotatedWith(Validates.class);
+		for (Method method: methods) {
+			Validates annotation =  method.getAnnotation(Validates.class);
+			handlers.put(annotation.timing() + "-validates:" + annotation.rule(),
+								   method,
+								   refs.computeIfAbsent(method.getDeclaringClass(),	type -> newInstance(type)));
+		}
+	}
+
+
+	private Object newInstance(Class theType) {
+		try {
+			return (getClass() == theType) ? this
+																 	   : theType.newInstance();
+		}
+		catch(Exception x) {
+			throw new RuntimeException(x); 
+		}
+	}
+
+	/*
+	 * Lookup one of the handlers, by handler type
+	 */
+	public <T> T getHandler(Class<T> theType) {
+		return (T)handlers.values()
+											.stream()
+									 	  .filter(h -> theType.isInstance(h))
+									 		.findFirst()
+									 		.orElse(null);
+	}
+
+	public CheckerConfiguration configuration() {
+		return this.config;
+	}
+
+	public void setTargetLocator(TargetLocator theLocator) {
+		this.locator = theLocator;
+	}
+
+	public TargetLocator getTargetLocator() {
+		return this.locator;
+	}
+	
+  public Collection<Target> targets() {
+		if (this.catalog == null)
+			throw new IllegalStateException("targets are only available after check");
+
+		return this.catalog.targets();
+	}
+
+	public Catalog catalog() {
+		return this.catalog;
+	}
+
+	/* a facility for handling all files in a target directory ..
+   */
+  public static Catalog check(File theSource)
+																	throws CheckerException {
+		
+		Catalog catalog = new Catalog(commonsCatalog());
+		Checker	checker = new Checker();
+		try {	
+			if (theSource.isDirectory()) {
+				for (File f: theSource.listFiles()) {
+    	  	if (f.isFile()) {
+      	  	checker.check(new Target(theSource.getCanonicalPath(), f.toURI().normalize()), catalog);
+      		}
+    		}
+			}
+			else {
+      	checker.check(new Target(theSource.getCanonicalPath(), theSource.toURI().normalize()), catalog);
+ 			}
+		}
+		catch (IOException iox) {
+			throw new CheckerException("Failed to initialize target", iox);
+		}
+
+		return catalog;
+	}
+	
+ 	/**
+	 * Main checking process entry point. In this case the source is passed to the locator in order to
+ 	 * obtain a {@link org.onap.tosca.checker.Target target}, and then all other processing stages are performed.
+	 * @param String the string representation of the uri pointing to the document/template to be processed
+	 * @throws CheckerException for any checker encountered error 
+	 */	
+  public void check(String theSource)
+																	throws CheckerException {
+		check(theSource, buildCatalog());
+	}
+
+	/**
+	 * Main checking entry point using a pre-computed Catalog. Same as {@link org.onap.tosca.checker.Chacker#check(String) check} except that the given catalog information is available. i.e. all types available in the given catalog types are
+available and the available targets won't be re-processed.
+	 */
+  public void check(String theSource, Catalog theCatalog)
+																							throws CheckerException {
+		Target tgt =
+					this.locator.resolve(theSource);
+		if (null == tgt) {
+			throw new CheckerException("Unable to locate the target " + theSource);
+		}
+
+		check(tgt, theCatalog);
+	}
+
+	/**
+	 * Starts the processing after the localization phase, i.e. the Target is obtained/constructed outside the checker.
+	 * @param Target the Target representation of the document/template to be processed. The actual target content (yaml
+	 *					character string) is obtained by calling {@link org.onap.tosca.checker.Target#open() open} on the target 
+	 * @throws CheckerException for any checker encountered error 
+	 */
+	public void check(Target theTarget) throws CheckerException {
+		check(theTarget, buildCatalog());
+	}
+
+	/**
+	 *
+	 * @param Target the Target representation of the document/template to be processed. The actual target content (yaml
+	 *					character string) is obtained by calling {@link org.onap.tosca.checker.Target#open() open} on the target 
+   * @param theCatalog a default catalog providing common construct definitions
+	 * @throws CheckerException for any checker encountered error 
+	 */
+	public void check(Target theTarget, Catalog theCatalog) throws CheckerException {
+
+		this.catalog = theCatalog;
+		this.locator.addSearchPath(theTarget.getLocation());
+		
+		if (this.catalog.addTarget(theTarget, null)) {
+			List<Target> targets = parseTarget(theTarget);
+			if (theTarget.getReport().hasErrors())
+				return;
+			for (Target target: targets) {
+				this.catalog.addTarget(target, null);
+				//what about this -> this.catalog.addTarget(target, theTarget);
+				if (!validateTarget(target).getReport().hasErrors()) {
+					checkTarget(target);
+				}
+			}
+		}
+	}
+
+	/**
+	 * Starts the processing after the {@link org.onap.tosca.checker.Staget#parsed parsed} stage. As such the Target must
+	 * have been located (content is available) and {@link org.onap.tosca.checker.Staget#parsed parsed} (the parsed form
+   * is stored within the Target, {@see org.onap.tosca.checker.Target#getTarget getTarget}).
+   * The target will be validated (grammar) and chcked (consistency). While the checker uses snakeyaml to parse
+	 * a yaml document using this entry point allows one to use any other yaml parser for a long as it produces a
+	 * compatible representation (java primitive types object representations, Strings, Maps and Lists).
+ 	 * 
+   * @param theTarget the processing subject, located and parsed.
+	 * @throws CheckerException for any checker encountered error 
+	 */
+	public void validate(Target theTarget) throws CheckerException {
+		validate(theTarget, buildCatalog());
+	}
+
+	/**
+	 *
+   * @param theTarget the processing subject, located and parsed.
+   * @param theCatalog a default catalog providing common construct definitions
+   * @throws CheckerException 
+	 */
+	public void validate(Target theTarget, Catalog theCatalog) throws CheckerException {
+		this.catalog = theCatalog;
+		this.locator.addSearchPath(theTarget.getLocation());
+		
+		if (this.catalog.addTarget(theTarget, null)) {
+			if (!validateTarget(theTarget).getReport().hasErrors()) {
+				checkTarget(theTarget);
+			}
+		}
+	}
+
+
+  /* */
+  protected List<Target> parseTarget(final Target theTarget)
+																		throws CheckerException {
+		log.entering(getClass().getName(), "parseTarget", theTarget);
+
+		Reader source = null;
+		try {
+			source = theTarget.open();
+		}
+		catch (IOException iox) {
+			throw new CheckerException("Failed to open target " + theTarget, iox);
+		}
+		
+
+		List<Object> yamlRoots = new ArrayList<Object>();
+    try {
+			Yaml yaml = new Yaml();
+			for (Object yamlRoot: yaml.loadAll(source)) {
+				yamlRoots.add(yamlRoot);
+			}
+
+			//yamlRoots.add(
+			//				new YamlParser(CharStreams.toString(source)).parse());
+    }
+/*
+		catch(SyntaxException sx) {
+			System.out.println(sx.getLineNumber() + ": " + sx.getMessage());
+			theTarget.report(sx);
+		}
+*/
+    catch(Exception x) {
+			theTarget.report(x);
+			return Collections.EMPTY_LIST;
+			//return Collections.singletonSet(theTarget);
+    }
+    finally {
+      try {
+        source.close();
+      }
+      catch (IOException iox) {
+        //just log it
+      }
+    }
+
+		List<Target> targets = new ArrayList<Target>(yamlRoots.size());
+		if (yamlRoots.size() == 1) {
+			//he target turned out to be a bare document
+			theTarget.setTarget(yamlRoots.get(0));
+			theTarget.setStage(Stage.parsed);
+			targets.add(theTarget);
+		}
+		else {	
+			//the target turned out to be a stream containing multiple documents
+			for (int i = 0; i < yamlRoots.size(); i++) {
+/*
+!!We're changing the target below, i.e. we're changing the target implementation hence caching implementation will suffer!!
+*/
+				Target target = new Target(theTarget.getName(), 
+																	 fragmentTargetURI(theTarget.getLocation(), String.valueOf(i)));
+				target.setTarget(yamlRoots.get(i));
+				target.setStage(Stage.parsed);
+				targets.add(target);
+			}
+		}
+	
+		log.exiting(getClass().getName(), "parseTarget", theTarget);
+    return targets;
+  }
+
+	protected URI fragmentTargetURI(URI theRoot, String theFragment) {
+		try {
+			return new URI(theRoot.getScheme(),
+  	      					 theRoot.getSchemeSpecificPart(),
+    	    					 theFragment);
+		}
+		catch(URISyntaxException urisx) {
+			throw new RuntimeException();
+		}
+	}
+
+  protected Target validateTarget(Target theTarget)
+																						throws CheckerException {
+		log.entering(getClass().getName(), "validateTarget", theTarget);
+	
+		String version = (String)
+											((Map)theTarget.getTarget())
+												.get("tosca_definitions_version");
+		if (version == null)
+			throw new CheckerException("Target " + theTarget + " does not specify a tosca_definitions_version");
+
+		Target grammar = this.grammars.get(version);
+		if (grammar == null)
+			throw new CheckerException("Target " + theTarget + " specifies unknown tosca_definitions_version " + version);
+
+		TOSCAValidator validator = null;
+    try {
+      validator = new TOSCAValidator(theTarget, grammar.getTarget());
+    }
+    catch (SchemaException sx) {
+      throw new CheckerException("Grammar error at: " + sx.getPath(), sx);
+    }
+
+    theTarget.getReport().addAll(
+				validator.validate(theTarget.getTarget()));
+		theTarget.setStage(Stage.validated);
+		
+		if (!theTarget.getReport().hasErrors()) {
+			//applyCanonicals(theTarget.getTarget(), validator.canonicals);
+    }
+    
+		log.exiting(getClass().getName(), "validateTarget", theTarget);
+		return theTarget;
+  }
+
+  /** */
+  protected Target checkTarget(Target theTarget) throws CheckerException {
+	
+		log.entering(getClass().getName(), "checkTarget", theTarget);
+
+		CheckContext ctx = new CheckContext(theTarget);
+    //start at the top
+		check_service_template_definition(
+			(Map<String,Object>)theTarget.getTarget(), ctx);
+
+		theTarget.setStage(Stage.checked);
+		log.exiting(getClass().getName(), "checkTarget", theTarget);
+		return theTarget;
+	}
+
+	private String errorReport(List<Throwable> theErrors) {
+    StringBuilder sb = new StringBuilder(theErrors.size() + " errors");
+    for (Throwable x: theErrors) {
+      sb.append("\n");
+			if (x instanceof ValidationException) {
+        ValidationException vx = (ValidationException)x;
+			  //.apend("at ")
+        //.append(error.getLineNumber())
+        //.append(" : ")
+				sb.append("[")
+          .append(vx.getPath())
+          .append("] ");
+      }
+			else if (x instanceof TargetError) {
+        TargetError tx = (TargetError)x;
+				sb.append("[")
+          .append(tx.getLocation())
+          .append("] ");
+			}
+			sb.append(x.getMessage());
+			if (x.getCause() != null) {
+				sb.append("\n\tCaused by:\n")
+          .append(x.getCause());
+			}
+    }
+		sb.append("\n");
+		return sb.toString();
+	}
+
+
+  protected void range_definition_post_validation_handler(Object theValue, Rule theRule, Validator.ValidationContext theContext) {
+    log.entering("", "range_definition", theContext.getPath());
+
+    assert theRule.getType().equals("seq");
+    List bounds = (List)theValue;
+
+    if (bounds.size() != 2) {
+      theContext.addError("Too many values in bounds specification", theRule, theValue, null);
+      return;
+    }
+
+    try { 
+      Double.parseDouble(bounds.get(0).toString());  
+    }  
+    catch(NumberFormatException nfe) {
+      theContext.addError("Lower bound not a number", theRule, theValue, null);
+    }  
+
+    try { 
+      Double.parseDouble(bounds.get(1).toString());  
+    }  
+    catch(NumberFormatException nfe) {
+      if (!"UNBOUNDED".equals(bounds.get(1).toString())) {
+        theContext.addError("Upper bound not a number or 'UNBOUNDED'", theRule, theValue, null);
+      }
+    }  
+    
+  }
+ 
+  public void check_properties(
+								Map<String,Map> theDefinitions, CheckContext theContext) {
+		theContext.enter("properties");
+    try {
+			if(!checkDefinition("properties", theDefinitions, theContext))
+				return;
+
+    	for (Iterator<Map.Entry<String,Map>> i = theDefinitions.entrySet().iterator(); i.hasNext(); ) {
+      	Map.Entry<String,Map> e = i.next();
+				check_property_definition(e.getKey(), e.getValue(), theContext);
+    	}
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+
+	protected void check_property_definition(
+							String theName, Map theDefinition, CheckContext theContext) {
+    theContext.enter(theName);
+		if (!checkName(theName, theContext) ||
+				!checkDefinition(theName, theDefinition, theContext)) {
+			return;
+    }
+    //check the type
+    if (!checkDataType (theName, theDefinition, theContext)) {
+			return;
+		}
+    //check default value is compatible with type
+		Object defaultValue = theDefinition.get("default");
+		if (defaultValue != null) {
+			checkDataValuation(defaultValue, theDefinition, theContext);
+		}
+
+		theContext.exit();
+  }
+  
+	public void check_attributes(
+								Map<String,Map> theDefinitions, CheckContext theContext) {
+		theContext.enter("attributes");
+    try {
+			if(!checkDefinition("attributes", theDefinitions, theContext))
+				return;
+
+  	  for (Iterator<Map.Entry<String,Map>> i = theDefinitions.entrySet().iterator(); i.hasNext(); ) {
+    	  Map.Entry<String,Map> e = i.next();
+				check_attribute_definition(e.getKey(), e.getValue(), theContext);
+    	}
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+
+  protected void check_attribute_definition(
+								String theName, Map theDefinition, CheckContext theContext) {
+    theContext.enter(theName);
+		try {
+			if (!checkName(theName, theContext) ||
+					!checkDefinition(theName, theDefinition, theContext)) {
+				return;
+    	}
+			if (!checkDataType(theName, theDefinition, theContext)) {
+				return;
+			}
+		}
+		finally {
+			theContext.exit();
+		}
+  }
+  
+	/* top level rule, we collected the whole information set.
+	 * this is where checking starts
+	 */
+  protected void check_service_template_definition(
+										Map<String, Object> theDef, CheckContext theContext) {
+    theContext.enter("");
+
+		if (theDef == null) {
+			theContext.addError("Empty template", null);
+			return;
+		}
+		
+		catalogs("", theDef, theContext); //root
+//!!! imports need to be processed first now that catalogging takes place at check time!! 
+		//first catalog whatever it is there to be cataloged so that the checks can perform cross-checking
+		for (Iterator<Map.Entry<String,Object>> ri = theDef.entrySet().iterator();
+		     ri.hasNext(); ) {
+			Map.Entry<String,Object> e = ri.next();
+			catalogs(e.getKey(), e.getValue(), theContext);
+		}
+
+		checks("", theDef, theContext); //root
+		for (Iterator<Map.Entry<String,Object>> ri = theDef.entrySet().iterator();
+		     ri.hasNext(); ) {
+			Map.Entry<String,Object> e = ri.next();
+			checks(e.getKey(), e.getValue(), theContext);
+		}
+    theContext.exit();
+  }
+
+	@Catalogs(path="/data_types")
+  protected void catalog_data_types(
+										Map<String, Map> theDefinitions, CheckContext theContext) {
+		theContext.enter("data_types");
+		try {
+			catalogTypes(Construct.Data, theDefinitions, theContext);
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+
+	@Checks(path="/data_types")
+  protected void check_data_types(
+										Map<String, Map> theDefinitions, CheckContext theContext) {
+		theContext.enter("data_types");
+		
+		try {
+			if(!checkDefinition("data_types", theDefinitions, theContext))
+		 		return;
+
+    	for (Iterator<Map.Entry<String,Map>> i = theDefinitions.entrySet().iterator(); i.hasNext(); ) {
+      	Map.Entry<String,Map> e = i.next();
+				check_data_type_definition(e.getKey(), e.getValue(), theContext);
+    	}
+		}
+		finally {
+			theContext.exit();
+		}
+  }
+
+  /* */
+  protected void check_data_type_definition(String theName,
+	                                          Map theDefinition,
+																						CheckContext theContext) {
+    theContext.enter(theName, Construct.Data);
+	  try {
+		  if (!checkName(theName, theContext) ||
+			    !checkDefinition(theName, theDefinition, theContext)) { 
+			  return;
+      }
+
+			checkTypeConstruct(
+			  Construct.Data, theName, theDefinition, theContext);
+
+      if (theDefinition.containsKey("properties")) {
+      	check_properties(
+					(Map<String,Map>)theDefinition.get("properties"), theContext);
+		    checkTypeConstructFacet(Construct.Data, theName, theDefinition, 
+																Facet.properties, theContext);
+			}
+    }
+		finally {
+		  theContext.exit();
+		}
+  }
+	
+	@Catalogs(path="/capability_types")
+  protected void catalog_capability_types(
+										Map<String, Map> theDefinitions, CheckContext theContext) {
+    theContext.enter("capability_types");
+		try {
+			catalogTypes(Construct.Capability, theDefinitions, theContext);
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+
+  /* */
+	@Checks(path="/capability_types")
+  protected void check_capability_types(
+	                    Map<String, Map> theTypes, CheckContext theContext) {
+    theContext.enter("capability_types");
+		try {
+			if(!checkDefinition("capability_types", theTypes, theContext))
+		 		return;
+
+  	  for (Iterator<Map.Entry<String,Map>> i = theTypes.entrySet().iterator(); i.hasNext(); ) {
+    	  Map.Entry<String,Map> e = i.next();
+      	check_capability_type_definition(e.getKey(), e.getValue(), theContext);
+    	}
+		}
+		finally {
+			theContext.exit();
+		}
+  }
+
+  /* */
+  protected void check_capability_type_definition(String theName,
+																									Map theDefinition,
+																									CheckContext theContext) {
+	  theContext.enter(theName, Construct.Capability);
+
+    try {
+		  if (!checkName(theName, theContext) ||
+			    !checkDefinition(theName, theDefinition, theContext)) {
+			  return;
+			}
+
+		  checkTypeConstruct(
+			  Construct.Capability, theName, theDefinition, theContext);
+
+      if (theDefinition.containsKey("properties")) {
+      	check_properties(
+					(Map<String,Map>)theDefinition.get("properties"), theContext);
+      	checkTypeConstructFacet(Construct.Capability, theName, theDefinition, 
+																Facet.properties, theContext);
+      }
+
+      if (theDefinition.containsKey("attributes")) {
+      	check_attributes(
+					(Map<String,Map>)theDefinition.get("attributes"), theContext);
+	    	checkTypeConstructFacet(Construct.Capability, theName, theDefinition,
+																Facet.attributes, theContext);
+			}
+
+	    //valid_source_types: see capability_type_definition
+  		//unclear: how is the valid_source_types list definition eveolving across
+	  	//the type hierarchy: additive, overwriting, ??
+		  if (theDefinition.containsKey("valid_source_types")) {
+			  checkTypeReference(Construct.Node, theContext, 
+				  ((List<String>)theDefinition.get("valid_source_types")).toArray(EMPTY_STRING_ARRAY));
+		  }
+    }
+		finally {
+		  theContext.exit();
+		}
+	}
+
+	@Catalogs(path="/relationship_types")
+  protected void catalog_relationship_types(
+										Map<String, Map> theDefinitions, CheckContext theContext) {
+		theContext.enter("relationship_types");
+		try {
+			catalogTypes(Construct.Relationship, theDefinitions, theContext);
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+
+  /* */
+	@Checks(path="/relationship_types")
+  protected void check_relationship_types(
+										Map<String, Map> theDefinition, CheckContext theContext) {
+		theContext.enter("relationship_types");
+		try {
+			if(!checkDefinition("relationship_types", theDefinition, theContext))
+		 		return;
+
+    	for (Iterator<Map.Entry<String,Map>> i = theDefinition.entrySet().iterator(); i.hasNext(); ) {
+      	Map.Entry<String,Map> e = i.next();
+      	check_relationship_type_definition(e.getKey(), e.getValue(), theContext);
+    	}
+		}
+		finally {
+			theContext.exit();
+		}
+  }
+ 
+  /* */
+	protected void check_relationship_type_definition(String theName,
+																										Map theDefinition,
+																										CheckContext theContext) {
+    theContext.enter(theName, Construct.Relationship);
+    try {
+		  if (!checkName(theName, theContext) ||
+			    !checkDefinition(theName, theDefinition, theContext)) {
+			  return;
+			}
+
+		  checkTypeConstruct(
+			  Construct.Relationship, theName, theDefinition, theContext);
+		  
+      if (theDefinition.containsKey("properties")) {
+      	check_properties(
+					(Map<String,Map>)theDefinition.get("properties"), theContext);
+				checkTypeConstructFacet(Construct.Relationship, theName, theDefinition,
+											 					Facet.properties, theContext); 
+			}
+			
+      if (theDefinition.containsKey("attributes")) {
+      	check_properties(
+					(Map<String,Map>)theDefinition.get("attributes"), theContext);
+				checkTypeConstructFacet(Construct.Relationship, theName, theDefinition,
+											 					Facet.attributes, theContext);
+			}
+
+			Map<String,Map> interfaces = (Map<String,Map>)theDefinition.get("interfaces");
+      if (interfaces != null) {
+			  theContext.enter("interfaces");
+        for (Iterator<Map.Entry<String,Map>> i =
+								interfaces.entrySet().iterator(); i.hasNext(); ) {
+          Map.Entry<String,Map> e = i.next();
+          check_type_interface_definition(
+						e.getKey(), e.getValue(), theContext);
+        }
+				theContext.exit();
+      }
+      
+		  if (theDefinition.containsKey("valid_target_types")) {
+			  checkTypeReference(Construct.Capability, theContext, 
+				  ((List<String>)theDefinition.get("valid_target_types")).toArray(EMPTY_STRING_ARRAY));
+			}
+    }
+		finally {
+		  theContext.exit();
+		}
+  }
+
+	@Catalogs(path="/artifact_types")
+  protected void catalog_artifact_types(
+										Map<String, Map> theDefinitions, CheckContext theContext) {
+    theContext.enter("artifact_types");
+		try {
+			catalogTypes(Construct.Artifact, theDefinitions, theContext);
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+
+  /* */
+	@Checks(path="/artifact_types")
+	protected void check_artifact_types(
+										Map<String, Map> theDefinition, CheckContext theContext) {
+    theContext.enter("artifact_types");
+		try {
+			if(!checkDefinition("artifact_types", theDefinition, theContext))
+		 		return;
+
+  	  for (Iterator<Map.Entry<String,Map>> i = theDefinition.entrySet().iterator(); i.hasNext(); ) {
+    	  Map.Entry<String,Map> e = i.next();
+				check_artifact_type_definition(e.getKey(), e.getValue(), theContext);
+    	}
+		}
+		finally {
+    	theContext.exit();
+		}
+  }
+	
+	/* */
+	protected void check_artifact_type_definition(String theName,
+																								Map theDefinition,
+																								CheckContext theContext) {
+    theContext.enter(theName, Construct.Artifact);
+    try {
+		  if (!checkName(theName, theContext) ||
+			    !checkDefinition(theName, theDefinition, theContext)) {
+			  return;
+			}
+
+		  checkTypeConstruct(
+			  Construct.Artifact, theName, theDefinition, theContext);
+		}
+		finally {
+		  theContext.exit();
+		}
+  }
+
+	@Catalogs(path="/interface_types")
+  protected void catalog_interface_types(
+										Map<String, Map> theDefinitions, CheckContext theContext) {
+    theContext.enter("interface_types");
+		try {
+			catalogTypes(Construct.Interface, theDefinitions, theContext);
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+
+	/* */
+	@Checks(path="/interface_types")
+  protected void check_interface_types(
+										Map<String, Map> theDefinition, CheckContext theContext) {
+    theContext.enter("interface_types");
+		try {
+			if(!checkDefinition("interface_types", theDefinition, theContext))
+		 		return;
+
+  	  for (Iterator<Map.Entry<String,Map>> i = theDefinition.entrySet().iterator(); i.hasNext(); ) {
+    	  Map.Entry<String,Map> e = i.next();
+				check_interface_type_definition(e.getKey(), e.getValue(), theContext);
+    	}
+		}
+		finally {
+			theContext.exit();
+		}
+  }
+	
+	/* */
+	protected void check_interface_type_definition(String theName,
+																								 Map theDefinition,
+																								 CheckContext theContext) {
+    theContext.enter(theName, Construct.Interface);
+    try {
+		  if (!checkName(theName, theContext) ||
+			    !checkDefinition(theName, theDefinition, theContext)) {
+			  return;
+			}
+
+		  checkTypeConstruct(
+			  Construct.Interface, theName, theDefinition, theContext);
+
+			//not much else here: a list of operation_definitions, each with its
+			//implementation and inputs
+
+			//check that common inputs are re-defined in a compatible manner
+
+			//check that the interface operations are overwritten in a compatible manner
+			//for (Iterator<Map.Entry<String,Map>> i = theDefinition.entrySet()
+
+    }
+		finally {
+		  theContext.exit();
+		}
+  }
+
+	@Catalogs(path="/node_types")
+  protected void catalog_node_types(
+										Map<String, Map> theDefinitions, CheckContext theContext) {
+    theContext.enter("node_types");
+		try {
+			catalogTypes(Construct.Node, theDefinitions, theContext);
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+
+  /* */
+	@Checks(path="/node_types")
+  protected void check_node_types(
+										Map<String, Map> theDefinition, CheckContext theContext) {
+    theContext.enter("node_types");
+		try {
+			if(!checkDefinition("node_types", theDefinition, theContext))
+		 		return;
+
+  	  for (Iterator<Map.Entry<String,Map>> i = theDefinition.entrySet().iterator(); i.hasNext(); ) {
+    	  Map.Entry<String,Map> e = i.next();
+				check_node_type_definition(e.getKey(), e.getValue(), theContext);
+    	}
+		}
+		finally {
+			theContext.exit();
+		}
+  }
+
+	
+	/* */
+	protected void check_node_type_definition(String theName,
+																						Map theDefinition,
+																						CheckContext theContext) {
+    theContext.enter(theName, Construct.Node);
+      
+	  try {
+		  if (!checkName(theName, theContext) ||
+			    !checkDefinition(theName, theDefinition, theContext)) {
+			  return;
+			}
+
+		  checkTypeConstruct(
+			  Construct.Node, theName, theDefinition, theContext);
+		  
+      if (theDefinition.containsKey("properties")) {
+      	check_properties(
+					(Map<String,Map>)theDefinition.get("properties"), theContext);
+				checkTypeConstructFacet(Construct.Node, theName, theDefinition,
+																Facet.properties, theContext);
+      }
+
+      if (theDefinition.containsKey("attributes")) {
+      	check_properties(
+					(Map<String,Map>)theDefinition.get("attributes"), theContext);
+				checkTypeConstructFacet(Construct.Node, theName, theDefinition, 
+																Facet.attributes, theContext);
+			}
+
+  		//requirements
+      if (theDefinition.containsKey("requirements")) {
+				check_requirements(
+				  (List<Map>)theDefinition.get("requirements"), theContext);
+			}
+
+  	  //capabilities
+      if (theDefinition.containsKey("capabilities")) {
+				check_capabilities(
+				  (Map<String,Map>)theDefinition.get("capabilities"), theContext);
+			}
+	  
+		  //interfaces: 
+			Map<String,Map> interfaces = 
+													(Map<String,Map>)theDefinition.get("interfaces");
+      if (interfaces != null) {
+				try {
+			  	theContext.enter("interfaces");
+        	for (Iterator<Map.Entry<String,Map>> i =
+									interfaces.entrySet().iterator(); i.hasNext(); ) {
+          	Map.Entry<String,Map> e = i.next();
+          	check_type_interface_definition(
+							e.getKey(), e.getValue(), theContext);
+        	}
+				}
+				finally {
+					theContext.exit();
+				}
+      }
+		  
+			//artifacts
+      
+    }
+		finally {
+		  theContext.exit();
+		}
+  }
+  
+	@Catalogs(path="/group_types")
+  protected void catalog_group_types(
+										Map<String, Map> theDefinitions, CheckContext theContext) {
+    theContext.enter("group_types");
+		try {
+			catalogTypes(Construct.Group, theDefinitions, theContext);
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+
+	/* */
+	@Checks(path="/group_types")
+  protected void check_group_types(
+										Map<String, Map> theDefinition, CheckContext theContext) {
+    theContext.enter("group_types");
+		try {
+			if(!checkDefinition("group_types", theDefinition, theContext))
+		 		return;
+
+  	  for (Iterator<Map.Entry<String,Map>> i = theDefinition.entrySet().iterator(); i.hasNext(); ) {
+    	  Map.Entry<String,Map> e = i.next();
+				check_group_type_definition(e.getKey(), e.getValue(), theContext);
+    	}
+		}
+		finally {
+			theContext.exit();
+		}
+  }
+	
+	/* */
+	protected void check_group_type_definition(String theName,
+																						Map theDefinition,
+																						CheckContext theContext) {
+    theContext.enter(theName, Construct.Group);
+      
+	  try {
+		  if (!checkName(theName, theContext) ||
+			    !checkDefinition(theName, theDefinition, theContext)) {
+			  return;
+			}
+
+		  checkTypeConstruct(
+			  Construct.Group, theName, theDefinition, theContext);
+      
+			if (theDefinition.containsKey("properties")) {
+      	check_properties(
+					(Map<String,Map>)theDefinition.get("properties"), theContext);
+				checkTypeConstructFacet(Construct.Group, theName, theDefinition,
+																Facet.properties, theContext);
+      }
+
+		  if (theDefinition.containsKey("targets")) {
+			  checkTypeReference(Construct.Node, theContext, 
+				  ((List<String>)theDefinition.get("targets")).toArray(EMPTY_STRING_ARRAY));
+		  }
+
+			//interfaces
+			Map<String,Map> interfaces = 
+													(Map<String,Map>)theDefinition.get("interfaces");
+      if (interfaces != null) {
+				try {
+				  theContext.enter("interfaces");
+      	  for (Iterator<Map.Entry<String,Map>> i =
+									interfaces.entrySet().iterator(); i.hasNext(); ) {
+     	     Map.Entry<String,Map> e = i.next();
+      	    check_type_interface_definition(
+							e.getKey(), e.getValue(), theContext);
+        	}
+				}
+				finally {
+					theContext.exit();
+				}
+      }
+
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+	
+	@Catalogs(path="/policy_types")
+  protected void catalog_policy_types(
+										Map<String, Map> theDefinitions, CheckContext theContext) {
+    theContext.enter("policy_types");
+		try {
+			catalogTypes(Construct.Policy, theDefinitions, theContext);
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+
+	/* */
+	@Checks(path="/policy_types")
+  protected void check_policy_types(
+										Map<String, Map> theDefinition, CheckContext theContext) {
+    theContext.enter("policy_types");
+		try {
+			if(!checkDefinition("policy_types", theDefinition, theContext))
+		 		return;
+
+  	  for (Iterator<Map.Entry<String,Map>> i = theDefinition.entrySet().iterator(); i.hasNext(); ) {
+    	  Map.Entry<String,Map> e = i.next();
+				check_policy_type_definition(e.getKey(), e.getValue(), theContext);
+    	}
+		}
+		finally {
+			theContext.exit();
+		}
+  }
+
+	/* */
+	protected void check_policy_type_definition(String theName,
+																						Map theDefinition,
+																						CheckContext theContext) {
+    theContext.enter(theName, Construct.Policy);
+      
+	  try {
+		  if (!checkName(theName, theContext) ||
+			    !checkDefinition(theName, theDefinition, theContext)) { 
+			  return;
+			}
+		  
+			checkTypeConstruct(
+			  Construct.Policy, theName, theDefinition, theContext);
+
+			if (theDefinition.containsKey("properties")) {
+      	check_properties(
+					(Map<String,Map>)theDefinition.get("properties"), theContext);
+				checkTypeConstructFacet(Construct.Policy, theName, theDefinition,
+																Facet.properties, theContext);
+      }
+
+			//the targets can be known node types or group types
+			List<String> targets = (List<String>)theDefinition.get("targets");
+			if (targets != null) {
+			  if (checkDefinition("targets", targets, theContext)) {
+					for (String target: targets) {
+						if (!(this.catalog.hasType(Construct.Node, target) ||
+								  this.catalog.hasType(Construct.Group, target))) {
+							theContext.addError(
+								Message.INVALID_TYPE_REFERENCE, "targets", target, Arrays.asList(Construct.Node, Construct.Group));
+						}
+					}
+				}
+		  }
+
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+
+  //checking of actual constructs (capability, ..)
+
+	/* First, interface types do not have a hierarchical organization (no 
+	 * 'derived_from' in a interface type definition).
+	 * So, when interfaces (with a certain type) are defined in a node
+	 * or relationship type (and they can define new? operations), what
+	 * is there to check:
+	 * 	Can operations here re-define their declaration from the interface
+	 * type spec?? From A.5.11.3 we are to understand indicates override to be
+	 * the default interpretation .. but they talk about sub-classing so it
+	 * probably intended as a reference to the node or relationship type
+	 * hierarchy and not the interface type (no hierarchy there).
+	 *	Or is this a a case of augmentation where new operations can be added??
+	 */
+  protected void check_type_interface_definition(
+			String theName, Map theDef, CheckContext theContext) {
+    theContext.enter(theName);
+    try {
+		  if (!checkName(theName, theContext) ||
+			    !checkDefinition(theName, theDef, theContext)) {
+			  return;
+			}
+
+			if (!checkTypeReference(Construct.Interface, theContext, (String)theDef.get("type")))
+				return;
+
+      if (theDef.containsKey("inputs")) {
+				check_inputs((Map<String, Map>)theDef.get("inputs"), theContext);
+			}
+
+			//operations: all entries except for 'type' and 'inputs'
+		/*
+      for (Iterator<Map.Entry<String,Map>> i = 
+							theDef.entrySet().iterator(); i.hasNext(); ) {
+        Map.Entry<String,Map> e = i.next();
+				String ename = e.getKey();
+				if ("type".equals(ename) || "inputs".equals(ename)) {
+					continue;
+				}
+			  ?? check_operation_definition(ename, e.getValue(), theContext);
+		  }
+		*/
+		}
+    finally {
+		  theContext.exit();
+		}
+  } 
+
+  /* */
+	protected void check_capabilities(Map<String,Map> theDefinition,
+																		CheckContext theContext) {
+    theContext.enter("capabilities");
+		try {
+			if(!checkDefinition("capabilities", theDefinition, theContext))
+		 		return;
+
+	    for (Iterator<Map.Entry<String,Map>> i = theDefinition.entrySet().iterator(); i.hasNext(); ) {
+  	    Map.Entry<String,Map> e = i.next();
+				check_capability_definition(e.getKey(), e.getValue(), theContext);
+    	}
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+
+  /* A capability definition appears within the context ot a node type
+	 */
+  protected void check_capability_definition(String theName,
+	                                           Map theDef,
+	                                           CheckContext theContext) {
+    theContext.enter(theName, Construct.Capability);
+
+    try {
+		  if (!checkName(theName, theContext) ||
+			    !checkDefinition(theName, theDef, theContext)) {
+			  return;
+			}
+
+      //check capability type
+		  if(!checkTypeReference(Construct.Capability, theContext, (String)theDef.get("type")))
+        return;
+    
+      //check properties
+      if (!checkFacetAugmentation(
+			  		Construct.Capability, theDef, Facet.properties, theContext))
+        return;    
+
+      //check attributes
+      if (!checkFacetAugmentation(
+				  	Construct.Capability, theDef, Facet.attributes, theContext))
+        return;    
+
+      //valid_source_types: should point to valid template nodes
+		  if (theDef.containsKey("valid_source_types")) {
+			  checkTypeReference(Construct.Node, theContext, 
+				  ((List<String>)theDef.get("valid_source_types")).toArray(EMPTY_STRING_ARRAY));
+				//per A.6.1.4 there is an additinal check to be performed here: 
+				//"Any Node Type (names) provides as values for the valid_source_types keyname SHALL be type-compatible (i.e., derived from the same parent Node Type) with any Node Types defined using the same keyname in the parent Capability Type."
+			}
+      //occurences: were verified in range_definition
+
+		}
+    finally {
+		  theContext.exit();
+		}
+  } 
+
+  protected void check_artifact_definition(String theName,
+																					 Map theDef,
+																					 CheckContext theContext) {
+    theContext.enter(theName, Construct.Artifact);
+
+    try {
+		  if (!checkName(theName, theContext) ||
+			    !checkDefinition(theName, theDef, theContext)) {
+			  return;
+			}
+      //check artifact type
+		  if(!checkTypeReference(Construct.Artifact, theContext, (String)theDef.get("type"))) 
+        return;
+		}
+		finally {
+		  theContext.exit();
+		}
+  }
+
+	protected void check_requirements(List<Map> theDefinition,
+																		CheckContext theContext) {
+    theContext.enter("requirements");
+    try {
+			if(!checkDefinition("requirements", theDefinition, theContext))
+		 		return;
+    
+			for (Iterator<Map> i = theDefinition.iterator(); i.hasNext(); ) {
+      	Map e = i.next();
+				Iterator<Map.Entry<String, Map>> ei =
+										(Iterator<Map.Entry<String, Map>>)e.entrySet().iterator();
+				Map.Entry<String, Map> eie = ei.next();
+				check_requirement_definition(eie.getKey(), eie.getValue(), theContext);
+				assert ei.hasNext() == false;
+    	}
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+
+  protected void check_requirement_definition(String theName,
+																							Map theDef,
+																							CheckContext theContext) {
+    theContext.enter(theName, Construct.Requirement);
+
+    try {
+		  if (!checkName(theName, theContext) ||
+			    !checkDefinition(theName, theDef, theContext)) {
+			  return;
+			}
+      //check capability type
+      String capabilityType = (String)theDef.get("capability");
+      if (null != capabilityType) {
+	   		checkTypeReference(Construct.Capability, theContext, capabilityType); 
+      }
+
+      //check node type
+      String nodeType = (String)theDef.get("node");
+      if (null != nodeType) {
+		  	checkTypeReference(Construct.Node, theContext, nodeType); 
+      }
+
+      //check relationship type
+      Map relationshipSpec = (Map)theDef.get("relationship");
+			String relationshipType = null;
+      if (null != relationshipSpec) {
+        relationshipType = (String)relationshipSpec.get("type");
+		  	if (relationshipType != null) { //should always be the case
+  		  	checkTypeReference(Construct.Relationship,theContext,relationshipType); 
+			  }
+
+			  Map<String,Map> interfaces = (Map<String,Map>)
+																					relationshipSpec.get("interfaces");
+        if (interfaces != null) {
+				  //augmentation (additional properties or operations) of the interfaces
+				  //defined by the above relationship types
+
+					//check that the interface types are known
+					for (Map interfaceDef : interfaces.values()) {
+						checkTypeReference(Construct.Interface, theContext, (String)interfaceDef.get("type"));
+					}
+			  }
+      }
+
+			//cross checks
+
+			//the capability definition might come from the capability type or from the capability definition
+			//within the node type. We might have more than one as a node might specify multiple capabilities of the
+			//same type.
+			//the goal here is to cross check the compatibility of the valid_source_types specification in the 
+			//target capability definition (if that definition contains a valid_source_types entry). 
+			List<Map> capabilityDefs = new LinkedList<Map>();
+			//nodeType exposes capabilityType
+			if (nodeType != null) {
+				Map<String,Map> capabilities =
+								findTypeFacetByType(Construct.Node, nodeType,
+																		Facet.capabilities, capabilityType);
+				if (capabilities.isEmpty()) {
+					theContext.addError("The node type " + nodeType + " does not appear to expose a capability of a type compatible with " + capabilityType, null);
+				}
+				else {
+					for (Map.Entry<String,Map> capability: capabilities.entrySet()) {
+						//this is the capability as it was defined in the node type
+						Map capabilityDef = capability.getValue();
+						//if it defines a valid_source_types then we're working with it,
+						//otherwise we're working with the capability type it points to.
+						//The spec does not make it clear if the valid_source_types in a capability definition augments or
+						//overwrites the one from the capabilityType (it just says they must be compatible).
+						if (capabilityDef.containsKey("valid_source_types")) {
+							capabilityDefs.add(capabilityDef);
+						}
+						else {
+							capabilityDef =
+								catalog.getTypeDefinition(Construct.Capability, (String)capabilityDef.get("type"));
+							if (capabilityDef.containsKey("valid_source_types")) {
+								capabilityDefs.add(capabilityDef);
+							}
+							else {
+								//!!if there is a capability that does not have a valid_source_type than there is no reason to
+								//make any further verification (as there is a valid node_type/capability target for this requirement)
+								capabilityDefs.clear();
+								break;
+							}
+						}
+					}
+				}
+			}
+			else {
+				Map capabilityDef =	catalog.getTypeDefinition(Construct.Capability, capabilityType);
+				if (capabilityDef.containsKey("valid_source_types")) {
+					capabilityDefs.add(capabilityDef);
+				}
+			}
+
+			//check that the node type enclosing this requirement definition
+			//is in the list of valid_source_types
+			if (!capabilityDefs.isEmpty()) {
+				String enclosingNodeType =
+										theContext.enclosingConstruct(Construct.Node).name();
+				assert enclosingNodeType != null;
+
+				if (!capabilityDefs.stream().anyMatch(
+							(Map capabilityDef)->{
+								List<String> valid_source_types =
+												(List<String>)capabilityDef.get("valid_source_types");
+								return valid_source_types.stream().anyMatch(
+									(String source_type)-> catalog.isDerivedFrom(
+												Construct.Node, enclosingNodeType, source_type));
+							})) {
+						theContext.addError("Node type: " + enclosingNodeType + " not compatible with any of the valid_source_types provided in the definition of compatible capabilities", null);
+
+				}
+
+				/*
+				boolean found = false;
+				for (Map capabilityDef: capabilityDefs) {
+
+					List<String> valid_source_types =
+											(List<String>)capabilityDef.get("valid_source_types");
+					String enclosingNodeType =
+										theContext.enclosingConstruct(Construct.Node);
+					assert enclosingNodeType != null;
+
+					//make sure enclosingNodeType is compatible (same or derived from)
+					//one valid source type
+					for (String source_type: valid_source_types) {
+						if (catalog.isDerivedFrom(
+									Construct.Node, enclosingNodeType, source_type)) {
+							found = true;
+							break;
+						}
+					}
+				}
+				
+				if (!found) {
+						//the message is not great as it points to the declared
+						//capabilityType which is not necessarly where the information
+						//is coming from
+						theContext.addError("Node type: " + enclosingNodeType + " not compatible with any of the valid_source_types " + valid_source_types + " provided in the definition of capability " + capabilityType, null);
+				}
+				*/
+			}
+
+			//if we have a relationship type, check if it has a valid_target_types
+			//if it does, make sure that the capability type is compatible with one
+			//of them
+		 	if (relationshipType != null) { //should always be the case
+				Map relationshipTypeDef = catalog.getTypeDefinition(
+																		Construct.Relationship, relationshipType);
+				if (relationshipTypeDef != null) {
+					List<String> valid_target_types =
+								(List<String>)relationshipTypeDef.get("valid_target_types");
+					if (valid_target_types != null) {
+						boolean found = false;
+						for (String target_type: valid_target_types) {
+							if (catalog.isDerivedFrom(
+										Construct.Capability, capabilityType, target_type)) {
+								found = true;
+								break;
+							}
+						}
+						if (!found) {
+							theContext.addError("Capability type: " + capabilityType + " not compatible with any of the valid_target_types " + valid_target_types + " provided in the definition of relationship type " + relationshipType, null);
+						}
+					}
+				}
+			}
+
+			//relationship declares the capabilityType in its valid_target_type set
+      //in A.6.9 'Relationship Type' the spec does not indicate how	inheritance
+			//is to be applied to the valid_target_type spec: cumulative, overwrites, 
+			//so we treat it as an overwrite.
+		}
+		finally {
+		  theContext.exit();
+		}
+  }
+  
+	//topology_template_definition and sub-rules
+	/* */
+	@Checks(path="/topology_template")
+	protected void check_topology_template(
+										Map<String,Map> theDef, final CheckContext theContext) {
+    
+		theContext.enter("topology_template");
+
+		try {		
+			theDef.entrySet().stream()
+				.forEach(e ->	catalogs(e.getKey(), e.getValue(), theContext));
+		
+			theDef.entrySet().stream()
+				.forEach(e ->	checks(e.getKey(), e.getValue(), theContext));
+/*		
+		for (Iterator<Map.Entry<String,Object>> ri = theDef.entrySet().iterator();
+		     ri.hasNext(); ) {
+			Map.Entry<String,Object> e = ri.next();
+			checks(e.getKey(), e.getValue(), theContext);
+		}
+*/
+		}
+		finally {
+			theContext.exit();
+		}
+  }
+
+  /*
+   * Once the syntax of the imports section is validated parse/validate/catalog    * all the imported template information
+   */
+	@Checks(path="/imports")
+  protected void check_imports(List theImports, CheckContext theContext) {
+    theContext.enter("imports");
+
+		for (ListIterator li = theImports.listIterator(); li.hasNext(); ) {
+			Object importEntry = li.next(),
+						 importFile =  ((Map)mapEntry(importEntry).getValue()).get("file");
+			Target tgt = null;
+			try {
+				tgt = catalog.getTarget( (URI)importFile );
+			}
+			catch (ClassCastException ccx) {
+				System.out.println("Import is " + importFile);
+			}
+
+			if (tgt == null) {
+				//malfunction
+    	  theContext.addError("Checking import '" + importFile + "': failed at a previous stage", null);
+				return;
+			}
+
+			if (tgt.getReport().hasErrors()) {
+				//import failed parsing or validation, we skip it
+				continue;
+			}
+
+			if (tgt.getStage() == Stage.checked) {
+				//been here before, this target had already been processed
+				continue;
+			}
+
+			//import should have been fully processed by now ??? 
+			log.log(Level.FINE, "Processing import " + tgt + ".");
+   	  try {
+      	checkTarget(tgt);
+     	}
+   	  catch (CheckerException cx) {
+    	  theContext.addError("Failure checking import '" + tgt + "'", cx);
+      }
+		 
+    }
+		theContext.exit();
+  }
+
+	/* */
+	@Checks(path="/topology_template/substitution_mappings")
+  protected void check_substitution_mappings(Map<String, Object> theSub,
+	                            							 CheckContext theContext) {
+    theContext.enter("substitution_mappings");
+		try {
+			//type is mandatory
+			String type = (String)theSub.get("node_type");
+  		if (!checkTypeReference(Construct.Node, theContext, type)) {
+				return;
+			}
+
+			Map<String,List> capabilities = (Map<String,List>)theSub.get("capabilities");
+			if (null != capabilities) {
+				for (Map.Entry<String,List> ce: capabilities.entrySet()) {
+					//the key must be a capability of the type
+					if (null == findTypeFacetByName(Construct.Node, type,
+																					Facet.capabilities, ce.getKey())) {
+    				theContext.addError("Unknown node type capability: " + ce.getKey() + ", type " + type, null);
+					}
+					//the value is a 2 element list: first is a local node, 
+					//second is the name of one of its capabilities
+					List target = ce.getValue();
+					if (target.size() != 2) {
+    				theContext.addError("Invalid capability mapping: " + target + ", expecting 2 elements", null);
+						continue;
+					}
+
+					String targetNode = (String)target.get(0),
+								 targetCapability = (String)target.get(1);
+				
+					Map<String,Object> targetNodeDef = (Map<String,Object>)
+												this.catalog.getTemplate(theContext.target(), Construct.Node, targetNode);
+					if (null == targetNodeDef) {
+    				theContext.addError("Invalid capability mapping node template: " + targetNode, null);
+						continue;
+					}
+
+					String targetNodeType = (String)targetNodeDef.get("type");
+					if (null == findTypeFacetByName(Construct.Node, targetNodeType,
+																		Facet.capabilities, targetCapability)) {
+    				theContext.addError("Invalid capability mapping capability: " + targetCapability + ". No such capability found for node template " + targetNode + ", of type " + targetNodeType, null);
+					}
+				}
+			}
+
+			Map<String,List> requirements = (Map<String,List>)theSub.get("requirements");
+			if (null != requirements) {
+				for (Map.Entry<String,List> re: requirements.entrySet()) {
+					//the key must be a requirement of the type
+					if (null == findNodeTypeRequirementByName(type, re.getKey())) {
+    				theContext.addError("Unknown node type requirement: " + re.getKey() + ", type " + type, null);
+					}
+
+					List target = re.getValue();
+					if (target.size() != 2) {
+    				theContext.addError("Invalid requirement mapping: " + target + ", expecting 2 elements", null);
+						continue;
+					}
+
+					String targetNode = (String)target.get(0),
+								 targetRequirement = (String)target.get(1);
+				
+					Map<String,Object> targetNodeDef = (Map<String,Object>)
+												this.catalog.getTemplate(theContext.target(), Construct.Node, targetNode);
+					if (null == targetNodeDef) {
+    				theContext.addError("Invalid requirement mapping node template: " + targetNode, null);
+						continue;
+					}
+
+					String targetNodeType = (String)targetNodeDef.get("type");
+					if (null == findNodeTypeRequirementByName(targetNodeType,targetRequirement)) {
+    				theContext.addError("Invalid requirement mapping requirement: " + targetRequirement + ". No such requirement found for node template " + targetNode + ", of type " + targetNodeType, null);
+					}
+				}
+			}
+		}
+		finally {
+		  theContext.exit();
+		}
+	}
+
+  /* */
+	@Catalogs(path="/topology_template/inputs")
+  protected void catalog_inputs(Map<String, Map> theInputs,
+	                            	CheckContext theContext) {
+    theContext.enter("inputs");
+
+		try {
+			catalogTemplates(Construct.Data, theInputs, theContext);
+    }
+		finally {
+			theContext.exit();
+		}
+	}
+
+  /* */
+	@Checks(path="/topology_template/inputs")
+  protected void check_inputs(Map<String, Map> theInputs,
+	                            CheckContext theContext) {
+    theContext.enter("inputs");
+
+    try {
+			if(!checkDefinition("inputs", theInputs, theContext))
+		 		return;
+    
+		  for (Iterator<Map.Entry<String,Map>> i = theInputs.entrySet().iterator(); i.hasNext(); ) {
+				Map.Entry<String,Map> e = i.next();
+				check_input_definition(e.getKey(), e.getValue(), theContext);
+    	}
+		}
+		finally {
+			theContext.exit();
+		}
+  }
+
+	/* */
+  protected void check_input_definition(String theName,
+																				Map theDef,
+																				CheckContext theContext) {
+    theContext.enter(theName);
+		try {
+		  if (!checkName(theName, theContext) ||
+			    !checkDefinition(theName, theDef, theContext)) {
+			  return;
+			}
+			//
+      if (!checkDataType(theName, theDef, theContext)) {
+				return;
+			}
+      //check default value
+			Object defaultValue = theDef.get("default");
+			if (defaultValue != null) {
+				checkDataValuation(defaultValue, theDef, theContext);
+			}
+		}
+		finally {
+		  theContext.exit();
+		}
+	}
+  
+	@Checks(path="topology_template/outputs")
+	protected void check_outputs(Map<String, Map> theOutputs,
+	                            CheckContext theContext) {
+    theContext.enter("outputs");
+
+    try {
+			if(!checkDefinition("outputs", theOutputs, theContext))
+		 		return;
+    
+		  for (Iterator<Map.Entry<String,Map>> i = theOutputs.entrySet().iterator(); i.hasNext(); ) {
+				Map.Entry<String,Map> e = i.next();
+				check_output_definition(e.getKey(), e.getValue(), theContext);
+    	}
+		}
+		finally {
+			theContext.exit();
+		}
+  }
+  
+	protected void check_output_definition(String theName,
+																				Map theDef,
+																				CheckContext theContext) {
+    theContext.enter(theName);
+		try {
+		  if (!checkName(theName, theContext) ||
+			    !checkDefinition(theName, theDef, theContext)) {
+			  return;
+			}
+			//check the expression
+		}
+		finally {
+		  theContext.exit();
+		}
+	}
+	
+	@Checks(path="/topology_template/groups")
+	protected void check_groups(Map<String, Map> theGroups,
+	                            CheckContext theContext) {
+    theContext.enter("groups");
+
+    try {
+			if(!checkDefinition("groups", theGroups, theContext))
+		 		return;
+    
+		  for (Iterator<Map.Entry<String,Map>> i = theGroups.entrySet().iterator(); i.hasNext(); ) {
+				Map.Entry<String,Map> e = i.next();
+				check_group_definition(e.getKey(), e.getValue(), theContext);
+    	}
+		}
+		finally {
+			theContext.exit();
+		}
+  }
+
+	protected void check_group_definition(String theName,
+																				Map theDef,
+																				CheckContext theContext) {
+    theContext.enter(theName);
+		try {
+		  if (!checkName(theName, theContext) ||
+			    !checkDefinition(theName, theDef, theContext)) {
+			  return;
+			}
+
+      if (!checkTypeReference(Construct.Group, theContext, (String)theDef.get("type")))
+        return;
+			
+			if (!checkFacet(
+					   Construct.Group, theDef, Facet.properties, theContext))
+        return;    
+		  
+			if (theDef.containsKey("targets")) {
+			  //checkTemplateReference(Construct.Node, theContext, 
+				//  ((List<String>)theDef.get("targets")).toArray(EMPTY_STRING_ARRAY));
+				
+				List<String> targetsTypes = (List<String>)
+					this.catalog.getTypeDefinition(Construct.Group,
+																				 (String)theDef.get("type"))
+												.get("targets");
+
+				List<String> targets = (List<String>)theDef.get("targets");
+				for (String target: targets) {
+					if (!this.catalog.hasTemplate(theContext.target(),Construct.Node, target)) {
+						theContext.addError("The 'targets' entry must contain a reference to a node template, '" + target + "' is not one", null);
+					}
+					else {
+						if (targetsTypes != null) {
+							String targetType = (String)
+								this.catalog.getTemplate(theContext.target(), Construct.Node, target).get("type");
+						
+							boolean found = false;
+							for (String type: targetsTypes) {
+								found = this.catalog
+												.isDerivedFrom(Construct.Node, targetType, type);
+								if (found)
+									break;
+							}
+						
+							if (!found) {
+								theContext.addError("The 'targets' entry '" + target + "' is not type compatible with any of types specified in policy type targets", null);
+							}
+						}
+					}
+				}
+		  }
+			
+			if (theDef.containsKey("interfaces")) {
+			}
+		}
+		finally {
+		  theContext.exit();
+		}
+	}
+
+	@Checks(path="/topology_template/policies")
+	protected void check_policies(List<Map<String,Map>> thePolicies,
+	                              CheckContext theContext) {
+    theContext.enter("policies");
+
+    try {
+			if(!checkDefinition("policies", thePolicies, theContext))
+		 		return;
+   
+		 	for (Map<String,Map> policy: thePolicies) {
+				assert policy.size() == 1;	
+				Map.Entry<String,Map> e = policy.entrySet().iterator().next();
+				check_policy_definition(e.getKey(), e.getValue(), theContext);
+			}
+		}
+		finally {
+			theContext.exit();
+		}
+  }
+	
+	protected void check_policy_definition(String theName,
+																				 Map theDef,
+																				 CheckContext theContext) {
+    theContext.enter(theName);
+		try {
+		  if (!checkName(theName, theContext) ||
+			    !checkDefinition(theName, theDef, theContext)) {
+			  return;
+			}
+      
+			if (!checkTypeReference(Construct.Policy, theContext, (String)theDef.get("type")))
+        return;
+      
+			if (!checkFacet(
+					   Construct.Policy, theDef, Facet.properties, theContext))
+        return;
+
+			//targets: must point to node or group templates (that are of a type
+			//specified in the policy type definition, if targets were specified
+			//there).
+		  if (theDef.containsKey("targets")) {
+				List<String> targetsTypes = (List<String>)
+					this.catalog.getTypeDefinition(Construct.Policy,
+																				 (String)theDef.get("type"))
+												.get("targets");
+
+				List<String> targets = (List<String>)theDef.get("targets");
+				for (String target: targets) {
+					Construct targetConstruct = null;
+
+					if (this.catalog.hasTemplate(theContext.target(),Construct.Group, target)) {
+						targetConstruct = Construct.Group;
+					}
+					else if (this.catalog.hasTemplate(theContext.target(),Construct.Node, target)) {
+						targetConstruct = Construct.Node;
+					}
+					else {
+						theContext.addError(Message.INVALID_TEMPLATE_REFERENCE, "targets", target, new Object[] {"node", "group"});
+					}
+						
+					if (targetConstruct != null &&
+							targetsTypes != null) {
+						//get the target type and make sure is compatible with the types
+						//indicated in the type spec
+						String targetType = (String)
+								this.catalog.getTemplate(theContext.target(), targetConstruct, target).get("type");	
+
+						boolean found = false;
+						for (String type: targetsTypes) {
+							found = this.catalog
+												.isDerivedFrom(targetConstruct, targetType, type);
+							if (found)
+								break;
+						}
+						
+						if (!found) {
+							theContext.addError("The 'targets' " + targetConstruct + " entry '" + target + "' is not type compatible with any of types specified in policy type targets", null);
+						}
+					}
+				}
+		  }
+
+			if (theDef.containsKey("triggers")) {
+				List<Map> triggers = (List<Map>)theDef.get("triggers");
+				//TODO
+			}
+
+		}
+		finally {
+		  theContext.exit();
+		}
+	}
+  
+	/* */
+	@Catalogs(path="/topology_template/node_templates")
+  protected void catalog_node_templates(Map<String, Map> theTemplates,
+	                            					CheckContext theContext) {
+    theContext.enter("node_templates");
+
+		try {
+			catalogTemplates(Construct.Node, theTemplates, theContext);
+    }
+		finally {
+			theContext.exit();
+		}
+	}
+
+  /* */
+	@Checks(path="/topology_template/node_templates")
+  protected void check_node_templates(Map<String, Map> theTemplates,
+	                                    CheckContext theContext) {
+    theContext.enter("node_templates");
+    try {
+			if(!checkDefinition("node_templates", theTemplates, theContext))
+		 		return;
+
+	    for (Iterator<Map.Entry<String,Map>> i = theTemplates.entrySet().iterator(); i.hasNext(); ) {
+  	    Map.Entry<String,Map> e = i.next();
+				check_node_template_definition(e.getKey(), e.getValue(), theContext);
+    	}
+		}
+		finally {
+			theContext.exit();
+		}
+  }
+
+	/* */
+  protected void check_node_template_definition(String theName,
+	                                              Map theNode,
+                                                CheckContext theContext) {
+    theContext.enter(theName, Construct.Node);
+
+    try {
+		  if (!checkName(theName, theContext) ||
+			    !checkDefinition(theName, theNode, theContext)) {
+			  return;
+			}
+
+      if (!checkTypeReference(Construct.Node, theContext, (String)theNode.get("type")))
+        return;
+			
+			//copy
+			String copy = (String)theNode.get("copy");
+			if (copy != null) {
+				if (!checkTemplateReference(Construct.Node, theContext, copy)) {
+					theContext.addError(Message.INVALID_TEMPLATE_REFERENCE, "copy", copy, Construct.Node);
+				}
+				else {
+					//the 'copy' node specification should be used to provide 'defaults'
+					//for this specification, we should check them
+				}
+			}
+
+      /* check that we operate on properties and attributes within the scope of
+	  	the specified node type */
+      if (!checkFacet(
+					   Construct.Node, /*theName,*/theNode, Facet.properties, theContext))
+        return;    
+
+      if (!checkFacet(
+						 Construct.Node, /*theName,*/theNode, Facet.attributes, theContext))
+        return;    
+
+    	//requirement assignment seq
+			if (theNode.containsKey("requirements")) {
+				check_requirements_assignment_definition(
+					(List<Map>)theNode.get("requirements"), theContext);
+			}
+
+			//capability assignment map: subject to augmentation
+			if (theNode.containsKey("capabilities")) {
+				check_capabilities_assignment_definition(
+						(Map<String,Map>)theNode.get("capabilities"), theContext);
+			}
+
+			//interfaces
+			if (theNode.containsKey("interfaces")) {
+				check_template_interfaces_definition(
+						(Map<String,Map>)theNode.get("interfaces"), theContext);
+			}
+
+			//artifacts: artifacts do not have different definition forms/syntax 
+			//depending on the context (type or template) but they are still subject 
+			//to 'augmentation'
+			if (theNode.containsKey("artifacts")) {
+				check_template_artifacts_definition(
+						(Map<String,Object>)theNode.get("artifacts"), theContext);
+			}
+
+			/* node_filter: the context to which the node filter is applied is very
+			 * wide here as opposed to the node filter specification in a requirement
+			 * assignment which has a more strict context (target node/capability are
+			 * specified).
+			 * We could check that there are nodes in this template having the 
+			 * properties/capabilities specified in this filter, i.e. the filter has
+			 * a chance to succeed.
+			 */
+    }
+		finally {
+			theContext.exit();
+		}
+  }
+  
+	@Checks(path="/topology_template/relationship_templates")
+  protected void check_relationship_templates(Map theTemplates,
+	                                            CheckContext theContext) {
+    theContext.enter("relationship_templates");
+
+    for (Iterator<Map.Entry<String,Map>> i = theTemplates.entrySet().iterator(); i.hasNext(); ) {
+      Map.Entry<String,Map> e = i.next();
+			check_relationship_template_definition(e.getKey(), e.getValue(), theContext);
+    }
+		theContext.exit();
+  }
+
+  /* */
+  protected void check_relationship_template_definition(
+																								String theName,
+																								Map theRelationship,
+																								CheckContext theContext) {
+    theContext.enter(theName, Construct.Relationship);
+    try {
+		  if (!checkName(theName, theContext) ||
+			    !checkDefinition(theName, theRelationship, theContext)) {
+			  return;
+			}
+
+      if (!checkTypeReference(Construct.Relationship, theContext, (String)theRelationship.get("type")))
+        return;
+			
+			String copy = (String)theRelationship.get("copy");
+			if (copy != null) {
+				if (!checkTemplateReference(Construct.Relationship, theContext, copy)) {
+					theContext.addError(Message.INVALID_TEMPLATE_REFERENCE, "copy", copy, Construct.Relationship);
+				}
+			}
+
+      /* check that we operate on properties and attributes within the scope of
+	  	the specified relationship type */
+      if (!checkFacet(Construct.Relationship, theRelationship,
+											Facet.properties, theContext))
+        return;    
+
+      if (!checkFacet(Construct.Relationship, theRelationship,
+											Facet.attributes, theContext))
+      return;    
+
+    /* interface definitions
+		   note: augmentation is allowed here so not clear what to check ..
+			 maybe report augmentations if so configured .. */
+
+    }
+		finally {
+			theContext.exit();
+		}
+	}
+
+  //requirements and capabilities assignment appear in a node templates
+  protected void check_requirements_assignment_definition(
+										List<Map> theRequirements, CheckContext theContext) {
+		theContext.enter("requirements");
+    try {
+			if(!checkDefinition("requirements", theRequirements, theContext))
+		 		return;
+		
+			//the node type for the node template enclosing these requirements
+			String nodeType =	(String)catalog.getTemplate(
+															theContext.target(),
+															Construct.Node,
+															theContext.enclosingConstruct(Construct.Node).name())
+																.get("type");
+		
+			for(Iterator<Map> ri = theRequirements.iterator(); ri.hasNext(); ) {
+				Map<String,Map> requirement = (Map<String,Map>)ri.next();
+			
+				Iterator<Map.Entry<String,Map>> rai = 
+					(Iterator<Map.Entry<String,Map>>)requirement.entrySet().iterator();
+			
+				Map.Entry<String,Map> requirementEntry = rai.next();
+				assert !rai.hasNext();
+
+				String requirementName = requirementEntry.getKey();
+				Map		 requirementDef = findNodeTypeRequirementByName(
+																								nodeType, requirementName);
+
+				if (requirementDef == null /*&&
+						!config.allowAugmentation()*/) {
+					theContext.addError("No requirement " + requirementName + " was defined for the node type " + nodeType, null);
+					continue;
+				}
+
+				check_requirement_assignment_definition(
+					requirementName, requirementEntry.getValue(), requirementDef, theContext);
+			}
+		}
+		finally {
+    	theContext.exit();
+		}
+	}
+	
+	protected void check_requirement_assignment_definition(
+																			String theRequirementName,
+																			Map theAssignment,
+																			Map theDefinition,
+																			CheckContext theContext) {
+		theContext//.enter("requirement_assignment")
+							.enter(theRequirementName, Construct.Requirement);
+		
+		//grab the node type definition to verify compatibility
+
+	  try {
+			//node assignment
+			boolean targetNodeIsTemplate = false;
+			String targetNode = (String)theAssignment.get("node");
+			if (targetNode == null) {
+				targetNode = (String)theDefinition.get("node");
+				//targetNodeIsTemplate stays false, targetNode must be a type
+			}
+			else {
+				//the value must be a node template or a node type
+				targetNodeIsTemplate = isTemplateReference(
+																	Construct.Node, theContext, targetNode);
+				if (!targetNodeIsTemplate) {
+			  	if (!isTypeReference(Construct.Node/*, theContext*/, targetNode)) {
+						theContext.addError(Message.INVALID_CONSTRUCT_REFERENCE, "node", targetNode, Construct.Node);
+						return;
+					}
+					//targetNode is a type reference
+				}
+			
+				//additional checks
+				String targetNodeDef = (String)theDefinition.get("node");
+				if (targetNodeDef != null && targetNode != null) {
+					if (targetNodeIsTemplate) {
+					//if the target is node template, it must be compatible with the
+					//node type specification in the requirement defintion
+						String targetNodeType = (String)
+								catalog.getTemplate(theContext.target(),Construct.Node,targetNode).get("type");
+						if (!catalog.isDerivedFrom(
+																Construct.Node, targetNodeType,targetNodeDef)) {
+							theContext.addError(Message.INCOMPATIBLE_REQUIREMENT_TARGET, Construct.Node, targetNodeType + " of target node " + targetNode, targetNodeDef);
+							return;
+						}
+					}
+					else {
+					//if the target is a node type it must be compatible (= or derived
+					//from) with the node type specification in the requirement definition
+						if (!catalog.isDerivedFrom(
+																Construct.Node, targetNode, targetNodeDef)) {
+							theContext.addError(Message.INCOMPATIBLE_REQUIREMENT_TARGET, Construct.Node, targetNode, targetNodeDef);
+							return;
+						}
+					}
+				}
+			}
+
+			String targetNodeType = targetNodeIsTemplate ?
+					(String)catalog.getTemplate(theContext.target(),Construct.Node,targetNode).get("type"):
+					targetNode;
+
+			//capability assignment
+      boolean targetCapabilityIsType = false;
+			String targetCapability = (String)theAssignment.get("capability");
+			if (targetCapability == null) {
+				targetCapability = (String)theDefinition.get("capability");
+				//in a requirement definition the target capability can only be a
+				//capability type (and not a capability name within some target node
+				//type)
+				targetCapabilityIsType = true;
+			}
+			else {
+        targetCapabilityIsType = isTypeReference(Construct.Capability, targetCapability);
+
+				//check compatibility with the target compatibility type specified
+				//in the requirement definition, if any
+				String targetCapabilityDef = (String)theDefinition.get("capability");
+				if (targetCapabilityDef != null && targetCapability != null) {
+					if (targetCapabilityIsType) {
+						if (!catalog.isDerivedFrom(
+								Construct.Capability, targetCapability, targetCapabilityDef)) {
+							theContext.addError(Message.INCOMPATIBLE_REQUIREMENT_TARGET, Construct.Capability, targetCapability, targetCapabilityDef);
+							return;
+						}
+					}
+					else {
+						//the capability is from a target node. Find its definition and
+						//check that its type is compatible with the capability type
+						//from the requirement definition
+
+						//check target capability compatibility with target node		
+						if (targetNode == null) {
+							theContext.addError("The capability '" + targetCapability + "' is not a capability type, hence it has to be a capability of the node template indicated in 'node', which was not specified", null);
+							return;
+						}
+						if (!targetNodeIsTemplate) {
+							theContext.addError("The capability '" + targetCapability + "' is not a capability type, hence it has to be a capability of the node template indicated in 'node', but there you specified a node type", null);
+							return;
+						}
+						//check that the targetNode (its type) indeed has the 
+						//targetCapability
+
+						Map<String,Object> targetNodeCapabilityDef = 
+																findTypeFacetByName(
+																			Construct.Node, targetNodeType,
+																			Facet.capabilities,	targetCapability);
+						if (targetNodeCapabilityDef == null) {
+							theContext.addError("No capability '" + targetCapability + "' was specified in the node " + targetNode + " of type " + targetNodeType, null);
+							return;
+						}
+
+						String targetNodeCapabilityType = (String)targetNodeCapabilityDef.get("type");
+
+						if (!catalog.isDerivedFrom(Construct.Capability,
+																			 targetNodeCapabilityType,
+																			 targetCapabilityDef)) {
+							theContext.addError("The required target capability type '" + targetCapabilityDef + "' is not compatible with the target capability type found in the target node type capability definition : " + targetNodeCapabilityType + ", targetNode " + targetNode + ", capability name " + targetCapability, null);
+							return;
+						}
+					}
+			  }
+			}
+		
+			//relationship assignment
+			Map targetRelationship = (Map)theAssignment.get("relationship");
+      if (targetRelationship != null) {
+				//this has to be compatible with the relationship with the same name
+				//from the node type
+				//check the type
+			}
+
+			//node_filter; used jxpath to simplify the navigation somewhat
+			//this is too cryptic
+	  	JXPathContext jxPath = JXPathContext.newContext(theAssignment);
+			jxPath.setLenient(true);
+
+			List<Map> propertiesFilter = 
+									(List<Map>)jxPath.getValue("/node_filter/properties");
+			if (propertiesFilter != null) {
+				for (Map propertyFilter: propertiesFilter) {
+//System.out.println("propertiesFilter " + propertyFilter);
+					
+					if (targetNode != null) {
+						//if we have a target node or node template then it must have
+						//have these properties
+						for (Object propertyName: propertyFilter.keySet()) {
+							if (null == findTypeFacetByName(Construct.Node,
+																						  targetNodeType,
+																							Facet.properties,
+																							propertyName.toString())) {
+								theContext.addError("The node_filter property " + propertyName + " is invalid: requirement target node " + targetNode + " does not have such a property", null);
+							}
+						}
+					}
+					else if (targetCapability != null) {
+			/*
+						//if we have a target capability type (but not have a target node)
+						//than it must have these properties
+
+			Not true, the filter always refer to node properties: it is the processor's/orchestrator job to match the
+			this requirement with a node that satisfies the filter. We cannot anticipate the values of all properties
+      (some might come from inputs) so we cannot scan for candidates at this point.
+
+
+						if (targetCapabilityIsType) {
+							for (Object propertyName: propertyFilter.keySet()) {
+								if (null == findTypeFacetByName(Construct.Capability,
+																								targetCapability,
+																								Facet.properties,
+																								propertyName.toString())) {
+									theContext.addError("The node_filter property " + propertyName + " is invalid: requirement target capability " + targetCapability + " does not have such a property", null);
+								}
+							}
+						}
+						else {
+							//cannot be: if you point to an explicit capability then you must
+							//have specified a targetNode
+						}
+				*/
+					}
+					else {
+						//what are the properties suppose to filter on ??
+					}
+				}
+			}
+
+			List<Map> capabilitiesFilter = 
+											(List<Map>)jxPath.getValue("node_filter/capabilities");
+			if (capabilitiesFilter != null) {
+				for (Map capabilityFilterDef: capabilitiesFilter) {
+					assert capabilityFilterDef.size() == 1;
+					Map.Entry<String, Map> capabilityFilterEntry = 
+							(Map.Entry<String, Map>)capabilityFilterDef.entrySet().iterator().next();
+					String targetFilterCapability = capabilityFilterEntry.getKey();
+					Map<String,Object> targetFilterCapabilityDef = null;
+
+					//if we have a targetNode capabilityName must be a capability of
+					//that node (type); or it can be simply capability type (but the node
+					//must have a capability of that type)
+
+					String targetFilterCapabilityType = null;
+					if (targetNode != null) {
+						targetFilterCapabilityDef = 
+								findTypeFacetByName(Construct.Node, targetNodeType,
+																		Facet.capabilities, targetFilterCapability);
+						if (targetFilterCapabilityDef != null) {
+							targetFilterCapabilityType =
+										(String)targetFilterCapabilityDef/*.values().iterator().next()*/.get("type");
+						}
+						else {
+							Map<String,Map> targetFilterCapabilities =
+								findTypeFacetByType(Construct.Node, targetNodeType,
+																		Facet.capabilities, targetFilterCapability);
+							
+							if (!targetFilterCapabilities.isEmpty()) {
+								if (targetFilterCapabilities.size() > 1) {
+									log.warning("check_requirement_assignment_definition: filter check, target node type '" + targetNodeType + "' has more than one capability of type '" + targetFilterCapability + "', not supported");
+								}
+								//pick the first entry, it represents a capability of the required type
+								Map.Entry<String,Map> capabilityEntry = targetFilterCapabilities.entrySet().iterator().next();
+								targetFilterCapabilityDef = Collections.singletonMap(capabilityEntry.getKey(),
+																																		 capabilityEntry.getValue());
+								targetFilterCapabilityType = targetFilterCapability;
+							}
+						}
+					}
+					else {
+						//no node (type) specified, it can be a straight capability type
+						targetFilterCapabilityDef = catalog.getTypeDefinition(
+																	Construct.Capability, targetFilterCapability);
+						//here comes the odd part: it can still be a just a name in which
+						//case we should look at the requirement definition, see which 
+						//capability (type) it indicates
+						assert targetCapabilityIsType; //cannot be otherwise, we'd need a node
+						targetFilterCapabilityDef = catalog.getTypeDefinition(
+																	Construct.Capability, targetCapability);
+						targetFilterCapabilityType = targetCapability;
+					}
+
+					if (targetFilterCapabilityDef == null) {
+						theContext.addError("Capability (name or type) " + targetFilterCapability + " is invalid: not a known capability (type) " + 
+						((targetNodeType != null) ? (" of node type" + targetNodeType) : ""), null);
+						continue;
+					}
+
+					for (Map propertyFilter: 
+									(List<Map>)jxPath.getValue("/node_filter/capabilities/" + targetFilterCapability + "/properties")) {
+						//check that the properties are in the scope of the 
+						//capability definition
+						for (Object propertyName: propertyFilter.keySet()) {
+							if (null == findTypeFacetByName(Construct.Capability,
+																							targetCapability,
+																							Facet.properties,
+																							propertyName.toString())) {
+									theContext.addError("The capability filter " + targetFilterCapability + " property " + propertyName + " is invalid: target capability " + targetFilterCapabilityType + " does not have such a property", null);
+							}
+						}
+					}
+				}
+			}
+
+		}
+		finally {
+			theContext//.exit()
+			          .exit();
+		}
+  }
+
+	protected void check_capabilities_assignment_definition(
+										Map<String,Map> theCapabilities, CheckContext theContext) {
+		theContext.enter("capabilities");
+    try {
+			if(!checkDefinition("capabilities", theCapabilities, theContext))
+		 		return;
+			
+			//the node type for the node template enclosing these requirements
+			String nodeType =	(String)catalog.getTemplate(
+															theContext.target(),
+															Construct.Node,
+															theContext.enclosingConstruct(Construct.Node).name())
+																.get("type");
+
+			for (Iterator<Map.Entry<String,Map>> ci =
+											theCapabilities.entrySet().iterator();
+			     ci.hasNext(); ) {
+				
+				Map.Entry<String,Map> ce = ci.next();
+
+				String capabilityName = ce.getKey();
+				Map		 capabilityDef = findTypeFacetByName(Construct.Node, nodeType,
+																			Facet.capabilities, capabilityName);
+				if (capabilityDef == null) {
+					theContext.addError("No capability " + capabilityName + " was defined for the node type " + nodeType, null);
+					continue;
+				}
+
+				check_capability_assignment_definition(
+					capabilityName, ce.getValue(), capabilityDef,theContext);
+			}
+		}
+		finally {
+ 	   theContext.exit();
+		}
+	}
+
+	protected void check_capability_assignment_definition(
+																			String theCapabilityName,
+																			Map theAssignment,
+																			Map theDefinition,
+																			CheckContext theContext) {
+
+		theContext.enter(theCapabilityName, Construct.Capability);
+	  try {
+			String capabilityType = (String)theDefinition.get("type");
+			//list of property and attributes assignments
+			checkFacet(Construct.Capability, theAssignment, capabilityType,
+								 Facet.properties, theContext);
+			checkFacet(Construct.Capability, theAssignment, capabilityType,
+								 Facet.attributes, theContext);
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+
+	/** */
+	protected void check_template_interfaces_definition(
+																				Map<String,Map> theInterfaces,
+																				CheckContext theContext) {
+		theContext.enter("interfaces");
+    try {
+			if(!checkDefinition("interfaces", theInterfaces, theContext))
+		 		return;
+			
+			//the node type for the node template enclosing these requirements
+			String nodeType =	(String)catalog.getTemplate(
+															theContext.target(),
+															Construct.Node,
+															theContext.enclosingConstruct(Construct.Node).name())
+																.get("type");
+
+			for (Iterator<Map.Entry<String,Map>> ii =
+											theInterfaces.entrySet().iterator();
+			     ii.hasNext(); ) {
+				
+				Map.Entry<String,Map> ie = ii.next();
+
+				String interfaceName = ie.getKey();
+				Map		 interfaceDef = findTypeFacetByName(Construct.Node,	nodeType, 
+																					Facet.interfaces, interfaceName);
+				
+				if (interfaceDef == null) {
+					/* this is subject to augmentation: this could be a warning but not an error */	
+					theContext.addError(Message.INVALID_INTERFACE_REFERENCE, nodeType, interfaceName, Construct.Node);
+					continue;
+				}
+
+				check_template_interface_definition(
+					interfaceName, ie.getValue(), interfaceDef, theContext);
+			}
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+	
+	protected void check_template_interface_definition(
+																			String theInterfaceName,
+																			Map theAssignment,
+																			Map theDefinition,
+																			CheckContext theContext) {
+
+		theContext.enter(theInterfaceName, Construct.Interface);
+	  try {
+			//check the assignment of the common inputs
+//System.out.println("Checking interface inputs for " + theInterfaceName);
+			checkFacet(Construct.Interface,
+								 theAssignment,
+								 (String)theDefinition.get("type"),
+								 Facet.inputs,
+								 theContext);
+
+			//check the assignment of inputs in each operation
+			//unfortunately operations are not defined as a facet (grouped under a
+			//facet name) i.e. operations..
+			
+/*
+			Map<String, Map> inputsDefs = theDefinition.get("inputs");
+			Map<String,?> inputs = theAssignment.get("inputs");
+			
+			if (inputs != null && !inputs.isEmpty()) {
+				for (Map.Entry inputEntry: input.entrySet()) {
+					//check the input name part of the definition
+					if (inputDefs != null && inputDefs.containsKey(inputEntry.getKey())) {
+						checkDataValuation(inputEntry.getValue(),
+															 inputsDefs.get(inputEntry.getKey()),
+															 theContext);						
+					}
+					else {
+						theContext.addError("No input " + inputEntry.getKey() + " was defined for the interface " + theInterfaceName, null);
+					}
+				}
+			}
+*/
+/*
+			String interfaceType = (String)theDefinition.get("type");
+			//list of property and attributes assignments
+			checkFacet(Construct.Interface, theAssignment, interfaceType,
+								 "inputs", theContext);
+*/
+			//the interface operations: can new operations be defined here??
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+
+	
+	@Checks(path="/topology_template/artifacts")
+	protected void check_template_artifacts_definition(
+																				Map<String,Object> theDefinition,
+																				CheckContext theContext) {		
+		theContext.enter("artifacts");
+    try {
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+	
+	protected void check_template_artifact_definition(
+																			String theArtifactName,
+																			Map theAssignment,
+																			Map theDefinition,
+																			CheckContext theContext) {
+
+		theContext.enter(theArtifactName, Construct.Artifact);
+	  try {
+
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+
+  //generic checking actions, not related to validation rules
+
+
+  /* the type can be:
+   *   a known type: predefined or user-defined
+   *   a collection (list or map) and then check that the entry_schema points to one of the first two cases (is that it?)
+   */
+  protected boolean checkDataType(
+											String theName, Map theSpec, CheckContext theContext) {
+	  
+		if (!checkTypeReference(Construct.Data, theContext, (String)theSpec.get("type")))
+      return false;
+
+	  String type = (String)theSpec.get("type");
+    if (/*isCollectionType(type)*/
+        "list".equals(type) || "map".equals(type)) {
+ 	   	Map entry_schema = (Map)theSpec.get("entry_schema");
+  	  if (entry_schema == null) {
+      	//maybe issue a warning ?? or is 'string' the default??
+       	return true;
+     	}
+
+			if (!catalog.hasType(Construct.Data,(String)entry_schema.get("type"))) {
+       	theContext.addError("Unknown entry_schema type: " + entry_schema, null);
+       	return false;
+     	}
+    }
+    return true;
+  }
+
+  /*
+	 * generic checks for a type specification
+	 */
+  protected boolean checkTypeConstruct(Construct theConstruct,
+	                                     String theTypeName,
+	                                     Map theDef,
+																			 CheckContext theContext) {
+		/* There is a 'weakness' in the super-type check before: the search for the supertype is done globally and 
+		 * not strictly on the 'import' path, i.e. one should explore for the super-type definition the target sub-tree
+		 * starting at the current target and not ALL the targets
+		 */
+		String parentType = (String)theDef.get("derived_from");
+		if (parentType != null && !catalog.hasType(theConstruct, parentType)) {
+			theContext.addError(
+				Message.INVALID_TYPE_REFERENCE, "derived_from", parentType, theConstruct);
+			return false;
+		}
+    return true;
+  }
+
+  /* Check that a particular facet (properties, attributes) of a construct type
+	 * (node type, capability type, etc) is correctly (consistenly) defined
+	 * across a type hierarchy
+	 */
+  protected boolean checkTypeConstructFacet(Construct theConstruct,
+	                                          String theTypeName,
+	                                          Map theTypeSpec,
+	                                          Facet theFacet,
+																			      CheckContext theContext) {
+    Map<String, Map> defs =
+		   	               (Map<String,Map>)theTypeSpec.get(theFacet.name());
+    if (null == defs) {
+      return true;
+    }
+
+    boolean res = true;
+
+    //given that the type was cataloged there will be at least one entry
+    Iterator<Map.Entry<String,Map>> i =
+															catalog.hierarchy(theConstruct, theTypeName);
+		if (!i.hasNext()) {
+      theContext.addError(
+			  "The type " + theTypeName + " needs to be cataloged before attempting 'checkTypeConstruct'", null);
+			return false;
+		}
+    i.next(); //skip self
+    while(i.hasNext()) {
+      Map.Entry<String,Map> e = i.next();
+      Map<String, Map> superDefs = (Map<String,Map>)e.getValue()
+																												.get(theFacet.name());
+      if (null == superDefs) {
+        continue;
+      }
+      //this computes entries that appear on both collections but with different values, i.e. the re-defined properties
+      Map<String, MapDifference.ValueDifference<Map>> diff = Maps.difference(defs, superDefs).entriesDiffering();
+      
+      for (Iterator<Map.Entry<String, MapDifference.ValueDifference<Map>>> di = diff.entrySet().iterator(); di.hasNext(); ) {
+         Map.Entry<String, MapDifference.ValueDifference<Map>> de = di.next();
+         MapDifference.ValueDifference<Map> dediff = de.getValue();
+         log.finest(
+           theConstruct + " type " + theFacet + ": " + de.getKey() + " has been re-defined between the " + theConstruct + " types " + e.getKey() + " and " + theTypeName);
+         //for now we just check that the type is consistenly re-declared
+         //if (!dediff.leftValue().get("type").equals(dediff.rightValue().get("type"))) {
+         if (!this.catalog.isDerivedFrom(theFacet.construct(),
+												 						(String)dediff.leftValue().get("type"),
+												 						(String)dediff.rightValue().get("type"))) {
+           theContext.addError(
+					  theConstruct + " type " + theFacet + ", redefiniton changed its type: "+ de.getKey() + " has been re-defined between the " + theConstruct + " types " + e.getKey() + " and " + theTypeName + " in an incompatible manner", null);
+           res = false;  
+         }
+      }
+    }
+
+    return res;   
+  }
+
+  /*
+	 * Checks the validity of a certain facet of a construct
+	 * (properties of a node) across a type hierarchy.
+   * For now the check is limited to a verifying that a a facet was declared
+	 * somewhere in the construct type hierarchy (a node template property has
+	 * been declared in the node type hierarchy).
+	 *
+	 * 2 versions with the more generic allowing the specification of the type
+	 * to be done explicitly.
+   */
+  protected boolean checkFacet(Construct theConstruct,
+															 Map theSpec,
+															 Facet theFacet,
+															 CheckContext theContext) {
+		return checkFacet(theConstruct, theSpec, null, theFacet, theContext);
+	}
+	
+	/**
+	 * We walk the hierarchy and verify the assignment of a property with respect to its definition.
+	 * We also collect the names of those properties defined as required but for which no assignment was provided.
+ 	 */
+	protected boolean checkFacet(Construct theConstruct,
+															 Map theSpec,
+															 String theSpecType,
+															 Facet theFacet,
+															 CheckContext theContext) {
+
+    Map<String,Map> defs = (Map<String,Map>)theSpec.get(theFacet.name());
+    if (null == defs) {
+      return true;
+    }
+    defs = Maps.newHashMap(defs); //
+    
+    boolean res = true;
+		if (theSpecType == null) {
+			theSpecType = (String)theSpec.get("type");
+    }
+		if (theSpecType == null) {
+       theContext.addError("No specification type available", null);
+			return false;
+		}
+
+		Map<String,Byte> missed = new HashMap<String, Byte>();  //keeps track of the missing required properties, the value is 
+																											 //false if a default was found along the hierarchy
+    Iterator<Map.Entry<String,Map>> i =
+													catalog.hierarchy(theConstruct, theSpecType);
+    while (i.hasNext() && !defs.isEmpty()) {
+      Map.Entry<String,Map> type = i.next();
+
+//System.out.println(" **** type : " + type.getKey() );
+
+      Map<String, Map> typeDefs = (Map<String,Map>)type.getValue()
+																													.get(theFacet.name());
+      if (null == typeDefs) {
+        continue;
+      }
+
+      MapDifference<String, Map> diff = Maps.difference(defs, typeDefs);
+      
+			//this are the ones this type and the spec have in common (same key,
+			//different values)
+      Map<String, MapDifference.ValueDifference<Map>> facetDefs = 
+																								diff.entriesDiffering();
+			//TODO: this assumes the definition of the facet is not cumulative, i.e.
+			//subtypes 'add' something to the definition provided by the super-types
+			//it considers the most specialized definition stands on its own
+			for (MapDifference.ValueDifference<Map> valdef: facetDefs.values()) {
+				checkDataValuation(valdef.leftValue(), valdef.rightValue(), theContext);
+			}
+
+			//the ones that appear in the type but not in spec; ensure the type does not requires them.
+/*
+			Map<String, Map> unassigned = diff.entriesOnlyOnRight();
+			for (Map.Entry<String, Map> unassignedEntry: unassigned.entrySet()) {
+
+System.out.println(" **** unassigned -> " + unassignedEntry.getKey() + " : " + unassignedEntry.getValue());
+
+				if (unassignedEntry.getValue().containsKey("required")) {
+					Boolean required = (Boolean)unassignedEntry.getValue().get("required");
+					System.out.println(" **** before " + unassignedEntry.getKey() + ", required " + required  + " = " + missed.get(unassignedEntry.getKey()));
+					missed.compute(unassignedEntry.getKey(),
+												 (k, v) -> v == null ? (required.booleanValue() ? (byte)1 
+																																				: (byte)0)
+																						 : (required.booleanValue() ? (byte)(v.byteValue() | 0x01)
+																																				: (byte)(v.byteValue() & 0x02)));
+
+
+					System.out.println(" **** after " + unassignedEntry.getKey() + ", required " + required  + " = " + missed.get(unassignedEntry.getKey()));
+				}
+				if (unassignedEntry.getValue().containsKey("default")) {
+					System.out.println(" **** before " + unassignedEntry.getKey() + ", default = " + missed.get(unassignedEntry.getKey()));
+					missed.compute(unassignedEntry.getKey(),
+												 (k, v) -> v == null ? (byte)2
+																						 : (byte)(v.byteValue() | 0x02));
+					System.out.println(" **** after " + unassignedEntry.getKey() + ", default = " + missed.get(unassignedEntry.getKey()));
+				}
+			}
+*/
+      //remove from properties all those that appear in this type: unfortunately this returns an unmodifiable map ..
+      defs = Maps.newHashMap(diff.entriesOnlyOnLeft());
+    }
+
+    if (!defs.isEmpty()) {
+			theContext.addError(Message.INVALID_FACET_REFERENCE, theConstruct, theFacet, theSpecType, defs);
+      res = false;
+    }
+
+		if (!missed.isEmpty()) {
+			List missedNames = 
+				missed.entrySet()
+							.stream()
+							.filter(e -> e.getValue().byteValue() == (byte)1)
+							.map(e -> e.getKey())
+							.collect(Collectors.toList());
+			if (!missedNames.isEmpty()) {
+      	theContext.addError(theConstruct + " " + theFacet + " missing required values for: " + missedNames, null);
+       	res = false;
+			}
+		}
+
+    return res;
+  }
+
+	/* Augmentation occurs in cases such as the declaration of capabilities within a node type.
+   * In such cases the construct facets (the capabilitity's properties) can redefine (augment) the 
+   * specification found in the construct type. 
+   */
+  protected boolean checkFacetAugmentation(Construct theConstruct,
+															 						 Map theSpec,
+															 						 Facet theFacet,
+															 						 CheckContext theContext) {
+		return checkFacetAugmentation(theConstruct, theSpec, null, theFacet, theContext);
+	}
+
+	protected boolean checkFacetAugmentation(Construct theConstruct,
+															 						 Map theSpec,
+																					 String theSpecType,
+																					 Facet theFacet,
+																					 CheckContext theContext) {
+    
+		Map<String,Map> augs = (Map<String,Map>)theSpec.get(theFacet.name());
+    if (null == augs) {
+      return true;
+    }
+    
+    boolean res = true;
+		if (theSpecType == null) {
+			theSpecType = (String)theSpec.get("type");
+    }
+		if (theSpecType == null) {
+       theContext.addError("No specification type available", null);
+			return false;
+		}
+
+		for (Iterator<Map.Entry<String,Map>> ai = augs.entrySet().iterator(); ai.hasNext(); ) {
+			Map.Entry<String,Map> ae = ai.next();
+			
+			//make sure it was declared by the type
+			Map facetDef = catalog.getFacetDefinition(theConstruct, theSpecType, theFacet, ae.getKey());
+			if (facetDef == null) {
+       	theContext.addError("Unknown " + theConstruct + " " + theFacet + " (not declared by the type " + theSpecType + ") were used: " + ae.getKey(), null);
+				res = false;
+				continue;
+			}
+
+			//check the compatibility of the augmentation: only the type cannot be changed
+			//can the type be changed in a compatible manner ??
+			if (!facetDef.get("type").equals(ae.getValue().get("type"))) {
+       	theContext.addError(theConstruct + " " + theFacet + " " + ae.getKey() + " has a different type than its definition: " + ae.getValue().get("type") + " instead of " + facetDef.get("type"), null);
+				res = false;
+				continue;
+			}
+
+			//check any valuation (here just defaults)
+			Object defaultValue = ae.getValue().get("default");
+			if (defaultValue != null) {
+				checkDataValuation(defaultValue, ae.getValue(), theContext);
+			}
+		}
+
+		return res;
+	}
+  
+  protected boolean catalogTypes(Construct theConstruct, Map<String,Map> theTypes, CheckContext theContext) {
+
+		boolean res = true;
+		for (Map.Entry<String,Map> typeEntry: theTypes.entrySet()) {
+			res &= catalogType(theConstruct, typeEntry.getKey(), typeEntry.getValue(), theContext); 
+		}
+
+		return res;
+	}
+
+  /* */
+	protected boolean catalogType(Construct theConstruct,
+															  String theName,
+															  Map theDef,
+															  CheckContext theContext) {
+			  
+		if (!catalog.addType(theConstruct, theName, theDef)) {
+			theContext.addError(theConstruct + " type " + theName + " re-declaration", null);
+			return false;
+		}
+		log.finer(theConstruct + " type " + theName + " has been cataloged");
+
+		return true;
+	}
+
+
+  /* */
+  protected boolean checkTypeReference(Construct theConstruct,
+																			 CheckContext theContext,
+																			 String... theTypeNames) {
+		boolean res = true;
+		for (String typeName: theTypeNames) {
+			if (!isTypeReference(theConstruct, typeName)) {
+				theContext.addError(Message.INVALID_TYPE_REFERENCE, "", typeName, theConstruct);
+				res = false;
+			}
+		}
+		return res;
+	}
+
+  protected boolean isTypeReference(Construct theConstruct,
+																		String theTypeName) {
+		return this.catalog.hasType(theConstruct, theTypeName);
+  }
+  
+	/* node or relationship templates */
+	protected boolean checkTemplateReference(Construct theConstruct,
+																			     CheckContext theContext,
+																			     String... theTemplateNames) {
+		boolean res = true;
+		for (String templateName: theTemplateNames) {
+			if (!isTemplateReference(theConstruct, theContext, templateName)) {
+				theContext.addError(Message.INVALID_TEMPLATE_REFERENCE, "", templateName, theConstruct);
+				res = false;
+			}
+		}
+		return res;
+  }
+  
+	protected boolean catalogTemplates(Construct theConstruct,
+																		 Map<String,Map> theTemplates,
+																		 CheckContext theContext) {
+
+		boolean res = true;
+		for (Map.Entry<String,Map> typeEntry: theTemplates.entrySet()) {
+			res &= catalogTemplate(theConstruct, typeEntry.getKey(), typeEntry.getValue(), theContext); 
+		}
+
+		return res;
+	}
+
+	protected boolean catalogTemplate(Construct theConstruct,
+															  		String theName,
+															  		Map theDef,
+															  		CheckContext theContext) {
+		try {
+	  	catalog.addTemplate(theContext.target(), theConstruct, theName, theDef);
+			log.finer(theConstruct + " " + theName + " has been cataloged");
+		}
+		catch(CatalogException cx) {
+		  theContext.addError("Failed to catalog " + theConstruct + " " + theName, cx);
+			return false;
+		}
+		return true;
+	}
+
+	protected boolean isTemplateReference(Construct theConstruct,
+																				CheckContext theContext,
+																				String theTemplateName) {
+		return this.catalog.hasTemplate(theContext.target(),theConstruct, theTemplateName);
+	}
+
+	/*
+	 * For inputs/properties/attributes/(parameters). It is the caller's
+	 * responsability to provide the value (from a 'default', inlined, ..)
+	 *
+	 * @param theDef the definition of the given construct/facet as it appears in
+	 * 			its enclosing type definition.
+	 * @param 
+	 */
+	protected boolean checkDataValuation(Object theExpr,
+																			 Map<String,?> theDef,
+																			 CheckContext theContext) {
+		//first check if the expression is a function, if not handle it as a value assignment
+		Data.Function f = Data.function(theExpr);
+		if (f != null) {
+			return f.evaluator()
+							 .eval(theExpr, theDef, theContext);
+		}
+		else {
+			Data.Type type = Data.typeByName((String)theDef.get("type"));
+			if (type != null) {
+//System.out.println("Evaluating " + theExpr + " as " + theExpr.getClass().getName() + " against " + theDef);
+				Data.Evaluator evaluator = null;
+
+				evaluator = type.evaluator();
+				if (evaluator == null) {
+					log.info("No value evaluator available for type " + type);
+				}
+				else {
+					if (theExpr != null) {
+						if (!evaluator.eval(theExpr, theDef, theContext)) {
+							return false;
+						}
+					}
+				}
+				
+				evaluator = type.constraintsEvaluator();
+				if (evaluator == null) {
+					log.info("No constraints evaluator available for type " + type);
+				}
+				else { 
+					if (theExpr != null) {
+						if (!evaluator.eval(theExpr, theDef, theContext)) {
+							return false;
+						}
+					}
+					else {
+						//should have a null value validator
+					}
+				}
+	
+				return true;
+			}
+			else {
+				theContext.addError("Expression " + theExpr + " of " + theDef + " could not be evaluated", null);
+				return false;
+			}
+		}
+	}
+
+	/** Given the type of a certain construct (node type for example), look up
+	 * in one of its facets (properties, capabilities, ..) for one of the given
+	 * facet type (if looking in property, one of the given data type).
+	 * @return a map of all facets of the given type, will be empty to signal
+	 * none found
+	 *
+	 * Should we look for a facet construct of a compatible type: any type derived
+	 * from the given facet's construct type??
+	 */
+	protected Map<String,Map> 
+									findTypeFacetByType(Construct theTypeConstruct,
+																	    String theTypeName,
+																			Facet theFacet,
+																			String theFacetType) {
+		
+		log.logp(Level.FINER, "", "findTypeFacetByType", theTypeName + " " +  theTypeConstruct + ": " + theFacetType + " " + theFacet);
+		Map<String,Map> res= new HashMap<String,Map>();
+    Iterator<Map.Entry<String,Map>> i =
+															catalog.hierarchy(theTypeConstruct, theTypeName);
+		while (i.hasNext()) {
+			Map.Entry<String,Map> typeSpec = i.next();
+			log.logp(Level.FINER, "", "findTypeFacetByType", "Checking " + theTypeConstruct + " type " + typeSpec.getKey() );
+			Map<String,Map> typeFacet =
+									(Map<String,Map>)typeSpec.getValue().get(theFacet.name());
+			if (typeFacet == null) {
+				continue;
+			}
+    	Iterator<Map.Entry<String,Map>> fi = typeFacet.entrySet().iterator();
+			while(fi.hasNext()) {
+				Map.Entry<String,Map> facet = fi.next();
+				String facetType = (String)facet.getValue().get("type");
+				log.logp(Level.FINER, "", "findTypeFacetByType", "Checking " + facet.getKey() + " type " + facetType);
+
+				//here is the question: do we look for an exact match or ..
+				//now we check that the type has a capability of a type compatible
+				//(equal or derived from) the given capability type.
+				if (catalog.isDerivedFrom(
+							theFacet.construct(), /*theFacetType, facetType*/facetType, theFacetType)) {
+					//res.merge(facet.getKey(), facet.getValue(), (currDef, newDef)->(merge the base class definition in the existing definition but provide the result in a new map as to avoid changing the stored defintitions));
+					res.putIfAbsent(facet.getKey(), facet.getValue());
+				}
+			}
+		}
+		log.logp(Level.FINER, "", "findTypeFacetByType", "found " + res);
+
+    return res;
+  }
+	
+	/* */
+	protected Map<String,Object>
+									findTypeFacetByName(Construct theTypeConstruct,
+																	    String theTypeName,
+																			Facet theFacet,
+																			String theFacetName) {
+		log.logp(Level.FINER, "", "findTypeFacetByName", theTypeConstruct + " " + theTypeName);
+    Iterator<Map.Entry<String,Map>> i =
+															catalog.hierarchy(theTypeConstruct, theTypeName);
+		while (i.hasNext()) {
+			Map.Entry<String,Map> typeSpec = i.next();
+			log.logp(Level.FINER, "", "findTypeFacetByName", "Checking " + theTypeConstruct + " type " + typeSpec.getKey() );
+			Map<String,Map> typeFacet =
+											(Map<String,Map>)typeSpec.getValue().get(theFacet.name());
+			if (typeFacet == null) {
+				continue;
+			}
+			Map<String,Object> facet = typeFacet.get(theFacetName);
+			if (facet != null) {
+				return facet;
+			}
+		}
+		return null;
+	}
+
+	/* Requirements are the odd ball as they are structured as a sequence ..
+	 */	
+	protected Map<String,Map> findNodeTypeRequirementByName(
+																String theNodeType, String theRequirementName) {
+		log.logp(Level.FINER, "", "findNodeTypeRequirementByName", theNodeType + "/" + theRequirementName);
+    Iterator<Map.Entry<String,Map>> i =
+															catalog.hierarchy(Construct.Node, theNodeType);
+		while (i.hasNext()) {
+			Map.Entry<String,Map> nodeType = i.next();
+			log.logp(Level.FINER, "", "findNodeTypeRequirementByName", "Checking node type " + nodeType.getKey() );
+			List<Map<String,Map>> nodeTypeRequirements =
+							(List<Map<String,Map>>)nodeType.getValue().get("requirements");
+			if (nodeTypeRequirements == null) {
+				continue;
+			}
+
+			for (Map<String,Map> requirement: nodeTypeRequirements) {
+				Map requirementDef = requirement.get(theRequirementName);
+				if (requirementDef != null) {
+					return requirementDef;
+				}
+			}
+		}
+		return null;
+	}
+
+	/*
+	 * 
+	 */
+	public Map findNodeTemplateInterfaceOperation(
+								Target theTarget, String theNodeName, String theInterfaceName, String theOperationName) {
+
+		Map nodeDefinition = (Map)catalog.getTemplate(theTarget, Construct.Node, theNodeName);
+		if (nodeDefinition == null)
+			return null;
+
+		Map interfaces = (Map)nodeDefinition.get("interfaces");
+		if (interfaces == null)
+			return null;
+
+		Map interfaceDef = (Map)interfaces.get(theInterfaceName);
+		if (interfaceDef == null)
+			return null;
+
+		return (Map)interfaceDef.get(theOperationName);
+	}
+
+	public Map findNodeTypeInterfaceOperation(
+								String theNodeType, String theInterfaceName, String theOperationName) {
+	
+		return null;	
+	}
+	
+  /*
+	 * Assumes that at this time the constrints (syntax) for all names (construct
+	 * types, constructs, facets: ) are the same.
+	 */
+	public boolean checkName(String theName,
+												      CheckContext theContext) {
+		return true;
+	}
+	
+	/*
+	 * Additional generics checks to be performed on any definition: construct,
+	 * construct types, etc ..
+	 */
+	public boolean checkDefinition(String theName,
+															Map theDefinition, 
+												      CheckContext theContext) {
+	  if (theDefinition == null) {
+		  theContext.addError("Missing definition for " + theName, null);
+				return false;
+		}
+	  
+		if (theDefinition.isEmpty()) {
+		  theContext.addError("Empty definition for " + theName, null);
+				return false;
+		}
+
+		return true;
+	}
+
+	public boolean checkDefinition(String theName,
+															List theDefinition, 
+												      CheckContext theContext) {
+	  if (theDefinition == null) {
+		  theContext.addError("Missing definition for " + theName, null);
+				return false;
+		}
+	  
+		if (theDefinition.isEmpty()) {
+		  theContext.addError("Empty definition for " + theName, null);
+				return false;
+		}
+
+		return true;
+	}
+
+	/* I'd rather validate each import once at it's own rule time (see next method) but unfortunately the canonicals
+	 * are not visible 'right away' (they are applied at the end of the pre-validation but not visible in the
+	 * post-validation of the same rule because of kwalify validator implementation).
+	 */
+	@Validates(rule="service_template_definition",timing=Validates.Timing.post)
+  protected void validate_imports(
+			Object theValue, Rule theRule, Validator.ValidationContext theContext) {
+
+		Map template = (Map)theValue;
+		List<Map> imports = (List)template.get("imports");
+
+		if (imports != null) {
+			for (Map importEntry: imports) {
+				validate_import(mapEntry(importEntry).getValue(), theRule, theContext);
+			}
+		}
+	}
+
+	//@Validates(rule="import_definition",timing=Validates.Timing.post)
+  protected void validate_import(
+			Object theValue, Rule theRule, Validator.ValidationContext theContext) {
+
+	  log.entering("", "import", theContext.getPath());
+					
+		TOSCAValidator validator = (TOSCAValidator)theContext.getValidator();
+		Target tgt = validator.getTarget();
+
+		Map def = (Map)theValue; //importEntry.getValue(); 
+		log.fine("Processing import " + def);
+
+		String tfile = (String)def.get("file");
+		Target tgti = this.locator.resolve(tfile);
+		if (tgti == null) {
+     	theContext.addError("Failure to resolve import '" + def + "', imported from " + tgt, theRule, null, null);
+     	return; 
+		}
+		log.finer("Import " + def + " located at " + tgti.getLocation());
+		
+		if (this.catalog.addTarget(tgti, tgt)) {
+	
+			//we've never seen this import (location) before
+			try {
+				List<Target> tgtis = parseTarget(tgti);
+				if (tgtis.isEmpty())
+					return; //continue;
+
+				if (tgtis.size() > 1) {
+       		theContext.addError("Import '" + tgti + "', imported from " + tgt + ", contains multiple yaml documents" , theRule, null, null);
+       		return; //continue;
+				}
+
+				tgti = tgtis.get(0);
+				if (tgt.getReport().hasErrors()) {
+       		theContext.addError("Failure parsing import '" + tgti + "',imported from " + tgt, theRule, null, null);
+					return; //continue;
+				}
+        	
+				validateTarget(tgti);
+				if (tgt.getReport().hasErrors()) {
+        	theContext.addError("Failure validating import '" + tgti + "',imported from " + tgt, theRule, null, null);
+					return; //continue;
+				}
+      }
+      catch (CheckerException cx) {
+       	theContext.addError("Failure validating import '" + tgti + "',imported from " + tgt, theRule, cx, null);
+      }
+		}
+
+		//replace with the actual location (also because this is what they get
+		//index by .. bad, this exposed catalog inner workings)
+		def.put("file", tgti.getLocation());
+	}
+	
+	/* plenty of one entry maps around */
+	private Map.Entry mapEntry(Object theMap) {
+		return (Map.Entry)((Map)theMap).entrySet().iterator().next();
+	}
+ 
+
+	/* */
+	protected static Catalog commonsCatalog = null;
+
+	/*
+	 * commons are built-in and supposed to be bulletproof so any error in here 
+	 * goes out loud.
+	 */
+	protected static Catalog commonsCatalog() {
+		
+		synchronized (Catalog.class) {
+			
+			if (commonsCatalog != null) {
+				return commonsCatalog;
+			}
+
+			//if other templates are going to be part of the common type system
+			//add them to this list. order is relevant.
+			final String[] commons = new String[] {
+																	"tosca/tosca-common-types.yaml" };
+		
+			Checker commonsChecker = null;
+			try {
+				commonsChecker = new Checker();
+
+				for (String common: commons) {
+					commonsChecker.check(common, buildCatalog(false));
+					Report commonsReport = commonsChecker.targets().iterator().next().getReport();
+
+					if (commonsReport.hasErrors()) {
+						throw new RuntimeException("Failed to process commons:\n" + 
+																				commonsReport);
+					}
+				}
+			}
+			catch(CheckerException cx) {
+				throw new RuntimeException("Failed to process commons", cx);
+			}
+
+			return commonsCatalog = commonsChecker.catalog;
+		}
+	}
+  
+	public static Catalog buildCatalog() {
+		return buildCatalog(true);
+	}
+
+  /*
+	 */
+  public static Catalog buildCatalog(boolean doCommons) {
+
+   	Catalog catalog = new Catalog(doCommons ? commonsCatalog() : null);
+		if (!doCommons) {
+    	//add core TOSCA types
+			for (Data.CoreType type: Data.CoreType.class.getEnumConstants()) {
+     		catalog.addType(Construct.Data, type.toString(), Collections.emptyMap());
+			}
+		}
+		return catalog;
+	}
+
+	protected void checks(String theName,
+ 	                      Object theTarget,
+											  CheckContext theContext) {
+
+		handles("checks:" + theContext.getPath(theName), theTarget, theContext);
+  }
+	
+	protected void catalogs(String theName,
+ 	                      	Object theTarget,
+											  	CheckContext theContext) {
+
+		handles("catalogs:" + theContext.getPath(theName), theTarget, theContext);
+	}
+	
+	protected boolean validates(Validates.Timing theTiming,
+	                 		        Object theTarget,
+															Rule theRule,
+															Validator.ValidationContext theContext) {
+		//might look odd but we need both 'handles' call to be executed
+		boolean validated = 
+			handles(theTiming + "-validates:" + theRule.getName(), theTarget, theRule, theContext);
+		return handles(theTiming + "-validates:", theTarget, theRule, theContext) || validated;
+	}
+
+	/*
+	 * allow the handlers to return a boolean .. only do this in order to accomodate the Canonical's way of avoiding
+	 * validation when a short form is encoutered.
+	 * @return true if any handler returned true (if they returned something at all), false otherwise (even when no
+   * handlers were found)
+	 */
+	protected boolean handles(String theHandlerKey, Object... theArgs) {
+
+		boolean handled = false;
+		Map<Method, Object> entries = handlers.row(theHandlerKey);
+		if (entries != null) {
+			for (Map.Entry<Method, Object> entry: entries.entrySet()) {
+				Object res = null;
+				try {
+					res = entry.getKey().invoke(entry.getValue(), theArgs);
+				}
+				catch (Exception x) {
+        	log.log(Level.WARNING, theHandlerKey + " by " + entry.getKey() + " failed", x);
+				}
+				handled |= res == null ? false : (res instanceof Boolean && ((Boolean)res).booleanValue());
+			}	
+		}
+		return handled;
+	}
+
+  /**
+	 */
+  public class TOSCAValidator extends Validator {
+
+		//what were validating
+   	private Target	target;
+			
+    public TOSCAValidator(Target theTarget, Object theSchema)
+																										throws SchemaException {
+      super(theSchema);
+			this.target = theTarget;
+    }
+
+		public Target getTarget() {
+			return this.target;
+		}
+
+    /* hook method called by Validator#validate() 
+     */
+    protected boolean preValidationHook(Object value, Rule rule, ValidationContext context) {
+
+			return validates(Validates.Timing.pre, value, rule, context);
+    }
+
+    /*
+     * Only gets invoked once the value was succesfully verified against the syntax indicated by the given rule.
+     */
+    protected void postValidationHook(Object value,
+		                                  Rule rule,
+																			ValidationContext context) {
+      validates(Validates.Timing.post, value, rule, context);
+    }
+
+  }
+
+  /** 
+	 * Maintains state across the checking process.
+	 */
+  public class CheckContext {
+
+		public class Step {
+
+		  private final Construct construct;
+ 			private final String		name;
+			private final Object		info;
+
+  		public Step(String theName, Construct theConstruct, Object theInfo) {
+    		this.construct = theConstruct;
+    		this.name = theName;
+    		this.info = theInfo;
+  		}
+
+  		public Construct 	construct() { return this.construct; }
+  		public String 		name() { return this.name; }
+  		public Object 		info() { return this.info; }
+		}		
+
+
+		private Target							target;
+	  private ArrayList<Step>			steps = new ArrayList<Step>(20); //artificial max nesting ..
+
+
+		public CheckContext(Target theTarget) {
+			this.target = theTarget;
+		}
+
+    public CheckContext enter(String theName) {
+    	return enter(theName, null, null);
+		}
+
+		public CheckContext enter(String theName, Construct theConstruct) {
+			return enter(theName, theConstruct, null);
+		}
+
+		public CheckContext enter(String theName, Construct theConstruct, Object theInfo) {
+			this.steps.add(new Step(theName, theConstruct, theInfo));
+      Checker.this.log.entering("check", theName, getPath());
+			return this;
+		}
+    
+		public CheckContext exit() {
+	 		Step step = this.steps.get(this.steps.size()-1);
+      Checker.this.log.exiting("check", step.name(), getPath());
+	 		this.steps.remove(this.steps.size()-1);
+		  return this;
+		}
+
+		public String getPath() {
+			return buildPath(null);
+		}
+
+		public String getPath(String theNextElem) {
+			return buildPath(theNextElem);
+		}
+
+		protected String buildPath(String theElem) {
+			StringBuffer sb = new StringBuffer("");
+			for (Step s: this.steps)
+				sb.append(s.name())
+					.append("/");
+			if (theElem != null)
+				sb.append(theElem)
+					.append("/");
+			
+			return sb.substring(0,sb.length()-1);
+		}
+
+    public Step enclosingConstruct(Construct theConstruct) {
+			for (int i = this.steps.size()-1; i > 0; i--) {
+			  Construct c = this.steps.get(i).construct();
+				if (c != null && c.equals(theConstruct)) {
+					return this.steps.get(i);
+				}
+			}
+			return null;
+		}
+    
+		public Step enclosingElement(String theName) {
+			for (int i = this.steps.size()-1; i > 0; i--) {
+			  String n = this.steps.get(i).name();
+				if (n != null && n.equals(theName)) {
+					return this.steps.get(i);
+				}
+			}
+			return null;
+		}
+
+		public Step enclosing() {
+			if (this.steps.size() > 0) {
+				return this.steps.get(this.steps.size()-1);
+			}
+			return null;
+		}
+
+		public CheckContext addError(String theMessage, Throwable theCause) {
+      this.target.report(new TargetError("", getPath(), theMessage, theCause));
+			return this;
+		}
+		
+		public CheckContext addError(Message theMsg, Object... theArgs) {
+			this.target.report(new TargetError("", getPath(), messages.format(theMsg, theArgs), null));
+			return this;
+		}
+
+    public boolean hasErrors() {
+			return this.target.getReport().hasErrors();
+		}
+
+		public Checker checker() {
+			return Checker.this;
+		}
+
+		public Catalog catalog() {
+			return Checker.this.catalog;
+		}
+
+		public Target target() {
+			return this.target;
+		}
+
+		public String toString() {
+			return "CheckContext(" + this.target.getLocation() + "," + getPath() + ")";
+		}
+	}
+
+	public static class CheckerConfiguration {
+
+		private boolean 	allowAugmentation = true;
+		private String		defaultImportsPath = null;
+		private String		defaultCheckerRoots = null;
+
+		protected CheckerConfiguration() {
+		}
+
+		public CheckerConfiguration allowAugmentation(boolean doAllow) {
+			this.allowAugmentation = doAllow;
+			return this;
+		}
+
+		public boolean allowAugmentation() {
+			return this.allowAugmentation;
+		}
+
+		public CheckerConfiguration defaultImportsPath(String thePath) {
+			this.defaultImportsPath = thePath;
+			return this;
+		}
+
+		public String defaultImportsPath() {
+			return this.defaultImportsPath;
+		}
+
+	}
+
+}
+
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/CheckerException.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/CheckerException.java
new file mode 100644
index 0000000..3751bb5
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/CheckerException.java
@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker;
+
+
+/**
+ * A checker exception represents an error that stops the checker from
+ * completing its task.
+ */
+public class CheckerException extends Exception {
+
+  public CheckerException(String theMsg, Throwable theCause) {
+    super(theMsg, theCause);
+  }
+
+  public CheckerException(String theMsg) {
+    super(theMsg);
+  }
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/CommonLocator.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/CommonLocator.java
new file mode 100644
index 0000000..f650f9e
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/CommonLocator.java
@@ -0,0 +1,156 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker;
+
+import java.io.InputStream;
+import java.io.IOException;
+
+import java.net.URL;
+import java.net.URI;
+import java.net.URISyntaxException;
+
+import java.nio.file.Paths;
+
+import java.util.Set;
+import java.util.LinkedHashSet;
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import com.google.common.collect.Iterables;
+
+
+public class CommonLocator implements TargetLocator {
+	
+	private static Logger log =
+		Logger.getLogger("com.att.research.is.tosca.yaml.TargetLocator");
+
+	private Set<URI> searchPaths = new LinkedHashSet(); 
+
+	/* will create a locator with 2 default search paths: the file directory 
+	 * from where the app was and the jar from which this checker (actually this
+	 * class) was loaded */
+	public CommonLocator() {
+		addSearchPath(
+			Paths.get(".").toAbsolutePath().normalize().toUri());
+	}
+	
+	public CommonLocator(String... theSearchPaths) {
+		for (String path: theSearchPaths) {
+			addSearchPath(path);
+		}
+	}
+
+	public boolean addSearchPath(URI theURI) {
+
+		if (!theURI.isAbsolute()) {
+			log.log(Level.WARNING, "Search paths must be absolute uris: " + theURI);
+			return false;
+		}
+
+		return searchPaths.add(theURI);
+	}
+
+	public boolean addSearchPath(String thePath) {
+		URI suri = null; 
+		try {
+			suri = new URI(thePath);
+		}
+		catch(URISyntaxException urisx) {
+			log.log(Level.WARNING, "Invalid search path: " + thePath, urisx);
+			return false;
+		}
+
+		return addSearchPath(suri);
+	}
+
+	public Iterable<URI> searchPaths() {
+		return Iterables.unmodifiableIterable(this.searchPaths);
+	}
+
+	/**
+	 * Takes the given path and first URI resolves it and then attempts to open
+	 * it (a way of verifying its existence) against each search path and stops
+	 * at the first succesful test.
+	 */
+	public Target resolve(String theName) {
+		URI puri = null;
+		InputStream	pis = null;
+
+		//try absolute
+		try {
+			puri = new URI(theName);
+			if (puri.isAbsolute()) {
+				try {
+					pis = puri.toURL().openStream();
+				}
+				catch (IOException iox) {
+					log.log(Level.WARNING, "The path " + theName + " is an absolute uri but it canont be opened", iox);
+					return null;
+				}
+			}
+		}
+		catch(URISyntaxException urisx) {
+			log.log(Level.FINER, "TargetResolver failed attempting " + puri, urisx);
+			//keep it silent but what are the chances ..
+		}
+
+		//try relative to the search paths
+		for (URI suri: searchPaths) {
+			try {
+				puri = suri.resolve(theName);
+				log.finer("TargetResolver trying " + puri);
+				pis = puri.toURL().openStream();
+				return new Target(theName, puri.normalize());
+			}
+			catch (Exception x) {
+				log.log(Level.FINER, "TargetResolver failed attempting " + puri, x);
+				continue;
+			}
+			finally {
+				if (pis!= null) {
+					try {
+						pis.close();
+					}
+					catch (IOException iox) {
+					}
+				}
+			}
+		}
+
+		//try classpath
+		URL purl = getClass().getClassLoader().getResource(theName);
+		if (purl != null) {
+			try {
+				return new Target(theName, purl.toURI());
+			}
+			catch (URISyntaxException urisx) {
+			}
+		}
+
+		return null;
+	}
+
+	public String toString() {
+		return "CommonLocator(" + this.searchPaths + ")";
+	}
+
+	
+	public static void main(String[] theArgs) {
+		TargetLocator tl = new CommonLocator();
+		tl.addSearchPath(java.nio.file.Paths.get("").toUri());
+		tl.addSearchPath("file:///");
+		System.out.println(
+				tl.resolve(theArgs[0]));
+	}
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Construct.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Construct.java
new file mode 100644
index 0000000..45108cb
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Construct.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker;
+
+/*
+ * What exactly is allowed to go in here is a subject of meditation :) I would have said 'elements with a type' but
+ * that will no cover Requirement and Workflow, or topology template top elements but won't cover others ..
+ * 
+ * Properties/Attributes/Inputs/Outputs are just Data constructs under a particular name.
+ */
+public enum Construct {
+    Data,
+		Requirement,
+    Capability,
+    Relationship,
+    Artifact,
+    Interface,
+    Node,
+		Group,
+		Policy,
+		Workflow
+}
+
+
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Data.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Data.java
new file mode 100644
index 0000000..fc29dcf
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Data.java
@@ -0,0 +1,923 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker;
+
+import java.lang.reflect.InvocationTargetException;
+
+import java.util.Collection;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.EnumSet;
+
+import java.util.logging.Logger;
+import java.util.logging.Level;
+
+import java.util.regex.Pattern;
+import java.util.regex.PatternSyntaxException;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.Table;
+import com.google.common.collect.HashBasedTable;
+
+/*
+ * tosca data type (primitive or user defined) evaluators and validators, used in checking valuations
+ */
+public class Data {
+
+	private static Logger log = Logger.getLogger(Data.class.getName());
+
+
+	private Data() {
+	}
+	
+	/*
+	 */
+	@FunctionalInterface
+	public static interface Evaluator {
+
+		public boolean eval(Object theExpr, Map theDef, Checker.CheckContext theCtx);	
+	}
+
+
+  /* data type processing */
+
+	private static Map<String,Type>	typesByName = new HashMap<String,Type>();
+	static {
+		//CoreType.String.toString();
+		//CoreFunction.concat.toString();
+		//Constraint.equal.toString();
+	}
+
+
+	public static Data.Type typeByName(String theName) {
+		return typesByName.getOrDefault(theName, userType);
+	}
+/*
+	public static Evaluator getTypeEvaluator(Type theType) {
+	}
+*/
+
+	/* Needs a better name ?? RValue?? 
+	 * This is not an rvalue (C def) per se but the construct who's instances
+	 * yield rvalues. It is a construct that yields data, not the data (yield)
+	 * itself.
+	 */
+	public static interface Type {
+		
+		public String name();
+
+		public Evaluator evaluator();
+
+		public Evaluator constraintsEvaluator();
+	}
+
+	/* generic placeholder
+	 */
+	private static Type userType = new Type() {
+	
+		public String name() {
+			return null;
+		}
+
+		public Evaluator evaluator() {
+			return Data::evalUser;
+		}
+
+		public Evaluator constraintsEvaluator() {
+			return Data::evalUserConstraints;
+		}
+	};
+
+
+	public static enum CoreType implements Type {
+
+    String("string",
+					(expr,def,ctx) -> expr != null && expr instanceof String,
+					Data::evalScalarConstraints),
+    Integer("integer",
+					(expr,def,ctx) -> Data.valueOf(ctx, expr, Integer.class),
+					Data::evalScalarConstraints),
+		Float("float",
+					(expr,def,ctx) -> Data.valueOf(ctx, expr, Double.class, Integer.class),
+					Data::evalScalarConstraints),
+ 	  Boolean("boolean",
+					(expr,def,ctx) -> Data.valueOf(ctx, expr, Boolean.class),
+					Data::evalScalarConstraints),
+ 	  Null("null",
+					(expr,def,ctx) -> expr.equals("null"),
+					null),
+   	Timestamp("timestamp",
+					(expr,def,ctx) -> timestampRegex.matcher(expr.toString()).matches(),
+					null),
+    List("list", Data::evalList, Data::evalListConstraints),
+    Map("map", Data::evalMap, Data::evalMapConstraints),
+		Version("version",
+					(expr,def,ctx) -> versionRegex.matcher(expr.toString()).matches(),
+					null),
+		/* use a scanner and check that the upper bound is indeed greater than
+		 * the lower bound */
+    Range("range",
+					(expr,def,ctx) -> { return rangeRegex.matcher(expr.toString()).matches();},
+					null ),
+    Size("scalar-unit.size",
+				 (expr,def,ctx) -> sizeRegex.matcher(expr.toString()).matches(),
+					null),
+    Time("scalar-unit.time",
+				 (expr,def,ctx) -> timeRegex.matcher(expr.toString()).matches(),
+					null),
+    Frequency("scalar-unit.frequency",
+				 (expr,def,ctx) -> frequencyRegex.matcher(expr.toString()).matches(),
+					null);
+
+
+		private String 		toscaName;
+		private Evaluator	valueEvaluator,
+											constraintsEvaluator;
+
+		private CoreType(String theName, Evaluator theValueEvaluator, Evaluator theConstraintsEvaluator) {
+			this.toscaName = theName;
+			this.valueEvaluator = theValueEvaluator;
+			this.constraintsEvaluator = theConstraintsEvaluator;
+
+			if (typesByName == null)
+				throw new RuntimeException("No type index available!");
+
+			typesByName.put(this.toscaName, this);
+		}
+
+		public String toString() {
+			return this.toscaName;
+		}
+
+		public Evaluator evaluator() {
+			return this.valueEvaluator;
+		}
+		
+		public Evaluator constraintsEvaluator() {
+			return this.constraintsEvaluator;
+		}
+	}
+
+	private static Pattern timestampRegex = null,
+												 versionRegex = null,
+												 rangeRegex = null,
+												 sizeRegex = null,
+												 timeRegex = null,
+												 frequencyRegex = null;
+
+	static {
+		try {
+			timestampRegex = Pattern.compile(
+					"\\p{Digit}+"); //?? where to find the definition
+
+			//<major_version>.<minor_version>[.<fix_version>[.<qualifier>[-<build_version]]]
+			versionRegex = Pattern.compile(
+					"\\p{Digit}+\\.\\p{Digit}+?(\\.\\p{Digit}+(\\.\\p{Alpha}+(\\-\\p{Digit}+))*)*");
+			
+			rangeRegex = Pattern.compile(
+					"\\[[ ]*\\p{Digit}+(\\.\\p{Digit}+)?[ ]*\\,[ ]*(\\p{Digit}+(\\.\\p{Digit}+)?|UNBOUNDED)[ ]*\\]");
+			
+			sizeRegex = Pattern.compile(
+					"\\p{Digit}+(\\.\\p{Digit}+)?[ ]*(B|kB|KiB|MB|MiB|GB|GiB|TB|TiB)");
+			
+			timeRegex = Pattern.compile(
+					"\\p{Digit}+(\\.\\p{Digit}+)?[ ]*(d|h|m|s|ms|us|ns)");
+			
+			frequencyRegex = Pattern.compile(
+					"\\p{Digit}+(\\.\\p{Digit}+)?[ ]*(Hz|kHz|MHz|GHz)");
+		}
+		catch (PatternSyntaxException psx) {
+			throw new RuntimeException("Bad patterns", psx);
+		}
+	}
+
+	/* */	
+	public static boolean evalScalarConstraints(Object theVal,
+																 							Map theDef,
+																 							Checker.CheckContext theCtx) {
+		Data.Type type = typeByName((String)theDef.get("type"));
+		List<Map<String,Object>> constraints =
+															(List<Map<String,Object>>)theDef.get("constraints");
+		if (constraints == null) {
+			return true;
+		}
+
+		//check value against constraints
+		boolean res = true;
+		for (Map<String,Object> constraintDef: constraints) {
+			Map.Entry<String,Object> constraintEntry =
+																		constraintDef.entrySet().iterator().next();
+			Data.Constraint constraint = constraintByName(constraintEntry.getKey());
+
+// the def passed here includes all constraints, not necessary! we can pass
+// simple constraintEntry.getValue()
+			Evaluator constraintEvaluator = getTypeConstraintEvaluator(type, constraint);
+			if (constraintEvaluator == null) {
+				log.info("No constaint evaluator available for " + type + "/" + constraint);
+				continue;
+			}
+
+			if (!constraintEvaluator.eval(theVal, theDef, theCtx)) {
+				theCtx.addError("Value " + theVal + " failed constraint " + constraintEntry, null);
+				res = false;
+			}
+		}
+		return res;
+	}
+
+	/*
+	 * It assumes the specification is complete, i.e. it contains a valid
+	 * entry_schema section.
+	 * TODO: check constraints, i.e. entrySchema.get("constraints")
+	 */
+	public static boolean evalList(Object theVal,
+																 Map theDef,
+																 Checker.CheckContext theCtx) {
+		try {
+			return evalCollection((List)theVal, theDef, theCtx);
+		}
+		catch (ClassCastException ccx) {
+			theCtx.addError("Value " + theVal + " not a list", null);
+			return false;
+		}
+	}
+	
+	public static boolean evalMap(Object theVal,
+																Map theDef,
+																Checker.CheckContext theCtx) {
+		try {
+			return evalCollection(((Map)theVal).values(), theDef, theCtx);
+		}
+		catch (ClassCastException ccx) {
+			theCtx.addError("Value " + theVal + " not a map", null);
+			return false;
+		}
+	}
+
+
+	/**
+	 * The elements of a collection can be of a core type or user defined type.
+   */
+	private static boolean evalCollection(Collection theVals,
+																 				Map theDef,
+																 				Checker.CheckContext theCtx) {
+
+//System.out.println("evalCollection: " + theDef + ", " + theVals);
+
+		Data.Type entryType = null;
+		Map entryTypeDef = (Map)theDef.get("entry_schema");
+		if (null != entryTypeDef)
+			entryType = typeByName((String)entryTypeDef.get("type"));
+
+//System.out.println("evalCollection, entry definition: " + entryTypeDef);
+		boolean res = true;
+		for (Object val: theVals) {
+			//check if the value is not a function call
+			Data.Function f = Data.function(val);
+			if (f != null &&
+					f.evaluator().eval(val, entryTypeDef, theCtx)) {
+				res = false;
+			}
+			else if (entryType != null &&
+							!entryType.evaluator().eval(val, entryTypeDef, theCtx)) {
+				res= false;
+				//the error should hav been reported by the particular evaluator
+				//theCtx.addError("Value " + val + " failed evaluation", null);
+			}
+		}
+		return res;
+	}
+	
+	public static boolean evalListConstraints(Object theVal,
+																 						Map theDef,
+																 						Checker.CheckContext theCtx) {
+		return evalCollectionConstraints((List)theVal, theDef, theCtx);
+	}
+	
+	public static boolean evalMapConstraints(Object theVal,
+																					 Map theDef,
+																					 Checker.CheckContext theCtx) {
+		return evalCollectionConstraints(((Map)theVal).values(), theDef, theCtx);
+	}
+
+	private static boolean evalCollectionConstraints(Collection theVals,
+																 									 Map theDef,
+																 									 Checker.CheckContext theCtx) {
+//System.out.println("evalCollectionConstraints: " + theDef + ", " + theVals);
+
+		//should check overall constraints 
+
+		if (theVals == null)
+			return true;
+
+		Map entryTypeDef = (Map)theDef.get("entry_schema");
+		if (null == entryTypeDef)
+			return true;
+
+		String entryTypeName = (String)entryTypeDef.get("type");
+		Data.Type entryType = typeByName(entryTypeName);
+
+//System.out.println("evalCollectionConstraints, entry definition: " + entryTypeDef);
+
+		boolean res = true;
+		for (Object val: theVals) {
+			Evaluator entryEvaluator = entryType.constraintsEvaluator();
+			if (entryEvaluator != null &&
+					!entryEvaluator.eval(val, entryTypeDef, theCtx)) {
+				res= false;
+				//the constraints evaluator should have already added an error, but it also adds some context 
+				//theCtx.addError("Value " + val + " failed evaluation", null);
+			}
+		}
+		return res;
+	}
+
+	/*
+	 * All required properties across the hierarchical defintion must be present
+	 * TODO:  The expr cannot contain any entry not specified in the type definition
+	 */
+	public static boolean evalUser(Object theVal,
+																 Map theDef,
+																 Checker.CheckContext theCtx) {
+//System.out.println("evalUser: " + theDef + ", " + theVal);
+
+		boolean res = true;
+		Map val = (Map)theVal;
+		//must be done with respect to the super-type(s) definition
+		Iterator<Map.Entry> props =	theCtx.catalog()
+																				.facets(Construct.Data,
+																								Facet.properties,
+																					 			(String)theDef.get("type"));	
+		while (props.hasNext()) {
+			Map.Entry propEntry = props.next();
+			Map propDef = (Map)propEntry.getValue();
+			Object propVal = val.get(propEntry.getKey());
+
+//System.out.println("evalUser: " + propVal);
+
+			if (propVal != null) {
+				Data.Type propType = typeByName((String)propDef.get("type"));
+
+				if (!propType.evaluator().eval(propVal, propDef, theCtx)) {
+					res= false;
+					//the constraints evaluator should have already added an error
+					//theCtx.addError("Property " + propEntry.getKey() + " failed evaluation for " + propVal, null);
+				}
+			}
+		}
+		return res;
+	}
+	
+	public static boolean evalUserConstraints(Object theVal,
+																 						Map theDef,
+																 						Checker.CheckContext theCtx) {
+		boolean res = true;
+		Map val = (Map)theVal;
+		Iterator<Map.Entry> props =	theCtx.catalog()
+																				.facets(Construct.Data,
+																								Facet.properties,
+																					 			(String)theDef.get("type"));	
+		while (props.hasNext()) {
+			Map.Entry propEntry = props.next();
+			Map propDef = (Map)propEntry.getValue();
+			Object propVal = val.get(propEntry.getKey());
+		
+			if (propVal != null) {
+				Data.Type propType = typeByName((String)propDef.get("type"));
+
+				if (propType.constraintsEvaluator() != null &&
+						!propType.constraintsEvaluator().eval(propVal, propDef, theCtx)) {
+					res= false;
+					//the constraints evaluator should have already added an error
+					//theCtx.addError("Property " + propEntry.getKey() + " failed evaluation for " + propVal, null);
+				}
+			}
+			else {
+				if (Boolean.TRUE == (Boolean)propDef.getOrDefault("required", Boolean.FALSE) &&
+						!propDef.containsKey("default")) {
+					theCtx.addError("Property " + propEntry.getKey() + " failed 'required' constraint; definition is " + propDef, null);
+					res = false;
+				}
+			}	
+		}
+		return res;
+	}
+
+	private static boolean valueOf(Checker.CheckContext theCtx,
+																 Object theExpr,
+																 Class ... theTypes) {
+		for (Class type: theTypes) {
+			if (type.isAssignableFrom(theExpr.getClass())) {
+				return true;
+			}
+		}
+				
+		theCtx.addError("Expression " + theExpr + " as " + theExpr.getClass().getName() + " is not compatible with any of required types: " + Arrays.toString(theTypes), null);
+		return false;
+	}
+
+/*
+	private static boolean valueOf(Class theTarget,
+																 String theExpr,
+																 Checker.CheckContext theCtx) {
+		try {
+			theTarget.getMethod("valueOf", new Class[] {String.class})
+								.invoke(null, theExpr);
+			return true;
+		}
+		catch (InvocationTargetException itx) {
+			theCtx.addError("Failed to parse " + theExpr + " as a " + theTarget.getName(), itx.getCause());
+			return false;
+		}
+		catch (Exception x) {
+			theCtx.addError("Failed to valueOf " + theExpr + " as a " + theTarget.getName(), x);
+			return false;
+		}
+	}
+*/
+
+	/* 
+	 * Function e(valuation)
+	 * ?
+	 * note to self : is there a more efficient way of retrieving a map's 
+	 * single entry? (without knowing the key)
+	 *
+	 * ! Function evaluators have to handle null definition (i.e. perform argument checking) so that
+	 * we can use them in the  context of collections with without entry_schemas
+	 */
+	
+	//just as Type but is it worth expressing this 'commonality'??
+	
+	public static interface Function {
+		
+		public String name();
+
+		public Evaluator evaluator();
+	}
+
+	/*
+	 * This is a heuristic induced from the tosca specification .. it answers the
+	 * question of wether the given expression is a function
+	 */
+	public static Function function(Object theExpr) {
+		if (theExpr instanceof Map &&
+				((Map)theExpr).size() == 1) {
+			try {
+				return Enum.valueOf(CoreFunction.class,	functionName(theExpr));
+			}
+			catch (IllegalArgumentException iax) {
+				//no such function but we cannot really record an error as we only guessed the expression as being a function ..
+				log.info("Failed attempt to interpret " + theExpr + " as a function call");
+			}
+		}
+		
+		return null;
+	}
+
+	/*
+	 */
+	public static String functionName(Object theExpr) {
+		return	(String)
+							((Map.Entry)
+								((Map)theExpr).entrySet().iterator().next())
+									.getKey();
+	}
+
+	/*
+	 */
+	public static Data.Function functionByName(String theName) {
+		return Enum.valueOf(CoreFunction.class, theName);
+	}
+
+	/*
+	 */	
+	public static enum CoreFunction implements Function {
+
+		concat(Data::evalConcat),
+		token(Data::evalToken),
+		get_input(Data::evalGetInput),
+		get_property(Data::evalGetProperty),
+		get_attribute(Data::evalGetAttribute),
+		get_operation_output((expr,def,ctx) -> true),
+		get_nodes_of_type(Data::evalGetNodesOfType),
+		get_artifact((expr,def,ctx) -> true);
+				 
+		private Evaluator	evaluator;
+
+		private CoreFunction(Evaluator theEval) {
+			this.evaluator = theEval;
+		}
+		
+		public Evaluator evaluator() {
+			return this.evaluator;
+		}
+	}
+
+	private static boolean evalConcat(
+						Object theVal, Map theDef, Checker.CheckContext theCtx) {
+		return true;
+	}
+	
+	private static boolean evalToken(
+						Object theVal, Map theDef, Checker.CheckContext theCtx) {
+		return true;
+	}
+
+	private static boolean evalGetInput(
+						Object theVal, Map theDef, Checker.CheckContext theCtx) {
+		Map val = (Map)theVal;
+		Map.Entry entry = (Map.Entry)val.entrySet().iterator().next();
+
+		if (!(entry.getValue() instanceof String)) {
+			theCtx.addError("get_input: argument must be a String" ,null);
+			return false;
+		}
+
+		//check that an input with the given name exists and has a compatible type
+		Map inputDef = theCtx.catalog()
+													.getTemplate(theCtx.target(), Construct.Data, (String)entry.getValue());
+		if (inputDef == null) {
+			theCtx.addError("get_input: no such input " + entry.getValue(), null);
+			return false;
+		}
+
+		if (theDef == null)
+			return true;
+
+		//the output must be type compatible with the input
+		String targetType = (String)theDef.get("type");
+		if (targetType != null) {
+			String inputType = (String)inputDef.get("type");
+
+			if (!theCtx.catalog()
+									.isDerivedFrom(Construct.Data, inputType, targetType)) {
+				theCtx.addError("get_input: input type " + inputType + " is incompatible with the target type " + targetType, null);
+				return false;
+			}
+		}
+
+		return true;
+	}
+
+	/*
+	 * Who's the smarty that decided to define optional arguments in between
+	 * required ones ?!
+	 * (factors the evaluation of get_attribute and get_property)
+	 */
+	private static boolean evalGetData(
+						Object theVal, Map theDef,
+						EnumSet<Facet> theFacets, Checker.CheckContext theCtx) {
+
+		Map val = (Map)theVal;
+		Map.Entry entry = (Map.Entry)val.entrySet().iterator().next();
+
+		if (!(entry.getValue() instanceof List)) {
+			theCtx.addError("get_property: argument must be a List" ,null);
+			return false;
+		}
+
+		List args = (List)entry.getValue();
+		if (args.size() < 2) {
+			theCtx.addError("'get_property' has at least 2 arguments", null);
+			return false;
+		}
+
+		//the first argument is a node or relationship template
+		String 		tmpl = (String)args.get(0);
+		Construct	tmplConstruct = null;
+		Map		 		tmplSpec = null;
+
+		if ("SELF".equals(tmpl)) {
+			tmpl = theCtx.enclosingConstruct(Construct.Node).name();
+			if (tmpl == null) {
+				tmpl = theCtx.enclosingConstruct(Construct.Relationship).name();
+				if (tmpl == null) {
+					theCtx.addError("'get_property' invalid SELF reference: no node or relationship template in scope at " + theCtx.getPath(), null);
+					return false;
+				}
+				else {
+					tmplConstruct = Construct.Relationship;
+				}
+			}
+			else {
+				tmplConstruct = Construct.Node;
+			}
+			tmplSpec = theCtx.catalog().getTemplate(theCtx.target(), tmplConstruct, tmpl);
+		}
+		else if ("SOURCE".equals("tmpl")) {
+			//we are in the scope of a relationship template and this is the source node template.
+			tmpl = theCtx.enclosingConstruct(Construct.Relationship).name();
+			if (tmpl == null) {
+				theCtx.addError("'get_property' invalid SOURCE reference: no relationship template in scope at " + theCtx.getPath(), null);
+				return false;
+			}
+			
+			return true;
+		}
+		else if ("TARGET".equals("tmpl")) {
+			//we are in the scope of a relationship template and this is the target node template.
+			tmpl = theCtx.enclosingConstruct(Construct.Relationship).name();
+			if (tmpl == null) {
+				theCtx.addError("'get_property' invalid TARGET reference: no relationship template in scope at " + theCtx.getPath(), null);
+				return false;
+			}
+
+			return true;
+		}
+		else if ("HOST".equals("tmpl")) {
+			tmpl = theCtx.enclosingConstruct(Construct.Node).name();
+			if (tmpl == null) {
+				theCtx.addError("'get_property' invalid HOST reference: no node template in scope at " + theCtx.getPath(), null);
+				return false;
+			}
+
+			return true;
+		}
+		else {
+			//try node template first
+			tmplSpec = theCtx.catalog().getTemplate(theCtx.target(), Construct.Node, tmpl);
+			if (tmplSpec == null) {
+				//try relationship
+				tmplSpec = theCtx.catalog().getTemplate(theCtx.target(), Construct.Relationship, tmpl);
+				if (tmplSpec == null) {
+					theCtx.addError("'get_data' invalid template reference '" + tmpl + "': no node or relationship template with this name", null);
+					return false;
+				}
+				else {
+					tmplConstruct = Construct.Relationship;
+				}
+			}
+			else {
+				tmplConstruct = Construct.Node;
+			}
+		}
+
+		int facetNameIndex = 1;
+		Construct facetConstruct = tmplConstruct; //who's construct the facet is supposed to belong to
+		Map 			facetConstructSpec = null;
+		String 		facetConstructType = null;
+
+		if (tmplConstruct.equals(Construct.Node) &&
+				args.size() > 2) {
+			//the second arg might be a capability or requirement name. If it is a
+			//capability than the third argument becomes a property of the
+			//coresponding capability type. If it is a requirement than the
+			//requirement definition indicates a capability who's type has a
+			//property with the name indicated in the third argument ..
+			//
+			//while the spec does not make it explicit this can only take place
+			//if the first argument turned out to be a node template (as relationship
+			//templates/types do not have capabilities/requirements
+			String secondArg = (String)args.get(1);
+			if ((facetConstructSpec = theCtx.catalog().getFacetDefinition(
+																						tmplConstruct,
+														 								(String)tmplSpec.get("type"),
+																						Facet.capabilities,
+																						secondArg)) != null) {
+				facetNameIndex = 2;
+				facetConstruct = Construct.Capability;
+				facetConstructType = (String)facetConstructSpec.get("type");
+			}
+			else if ((facetConstructSpec = theCtx.catalog().getRequirementDefinition(
+																							tmplConstruct,
+																							(String)tmplSpec.get("type"),
+																							secondArg)) != null) {	
+				facetNameIndex = 2;
+				facetConstruct = Construct.Capability;
+				
+				//find the specof the capability this requirement points to
+				//TODO: check, can the capability reference be anything else but a capability tyep?
+				facetConstructType = (String)facetConstructSpec.get("capability");
+			}
+		}
+		else {
+			//we'll attempt to handle it as a property of the node template
+			facetConstruct = Construct.Node;
+			facetConstructSpec = tmplSpec;
+			facetConstructType = (String)facetConstructSpec.get("type");
+		}
+	
+		//validate the facet name
+		Map facetSpec = null;
+		{
+			String facetName = (String)args.get(facetNameIndex);
+			for (Facet facet: theFacets) {
+//System.out.println("get_data: looking at " + facetConstruct + " " + facetConstructType + ", " + facet + " " + facetName);
+				facetSpec = theCtx.catalog()
+											.getFacetDefinition(
+														facetConstruct,
+														facetConstructType,
+										  			facet,
+														facetName);
+				if (facetSpec != null)
+					break;
+			}
+
+			if (facetSpec == null) {
+//TODO: not the greatest message if the call strated with a requirement ..
+				theCtx.addError("'get_data' invalid reference, '" + facetConstruct + "' " + facetConstructType + " has no " + theFacets + " with name " + facetName, null);
+				return false;
+			}
+		}
+
+		//the rest of the arguments have to resolve to a field of the property's
+		//data type; the propertySpec contains the type specification
+		for (int i = facetNameIndex + 1; i < args.size(); i++)  {
+		}
+
+		return true;
+	}
+	
+	/**/
+	private static boolean evalGetProperty(
+						Object theVal, Map theDef, Checker.CheckContext theCtx) {
+		return evalGetData(theVal, theDef, EnumSet.of(Facet.properties), theCtx);
+	}
+
+	/*
+	 * get_property and get_attribute are identical, just operating on different
+	 * facets, with one exception: there is an intrinsec attribute for every 
+	 * declared property.
+	 */
+	private static boolean evalGetAttribute(
+						Object theVal, Map theDef, Checker.CheckContext theCtx) {
+		return evalGetData(theVal, theDef, EnumSet.of(Facet.attributes, Facet.properties), theCtx);
+	}
+
+	private static boolean evalGetNodesOfType(
+						Object theVal, Map theDef, Checker.CheckContext theCtx) {
+		
+		Map val = (Map)theVal;
+		Map.Entry entry = (Map.Entry)val.entrySet().iterator().next();
+
+		if (!(entry.getValue() instanceof String)) {
+			theCtx.addError("get_nodes_of_type: argument must be a String", null);
+			return false;
+		}
+
+		String arg = (String)entry.getValue();
+
+		if (null == theCtx.catalog().getTypeDefinition(Construct.Node, arg)) {
+			theCtx.addError("get_nodes_of_type: no such node type " + arg, null);
+			return false;
+		}
+		else {
+			return true;
+		}
+	}
+
+	/* */
+	public static Constraint constraintByName(String theName) {
+		return Enum.valueOf(Constraint.class,	theName);
+	}
+
+	/* */	
+	public static Constraint constraint(Object theExpr) {
+		if (theExpr instanceof Map &&
+				((Map)theExpr).size() == 1) {
+			return constraintByName(constraintName(theExpr));
+		}
+		
+		return null;
+	}
+
+	/* */
+	public static String constraintName(Object theExpr) {
+		return	(String)
+							((Map.Entry)
+								((Map)theExpr).entrySet().iterator().next())
+									.getKey();
+	}
+
+	private static Object getConstraintValue(Map theDef,
+																					 Constraint theConstraint) {
+		List<Map> constraints = (List<Map>)theDef.get("constraints");
+		if (null == constraints)
+			return null;
+
+		for(Map constraint: constraints) {
+			Object val = constraint.get(theConstraint.toString());
+			if (val != null)
+				return val;
+		}
+		return null;
+	}
+
+	public static enum Constraint {
+		equal,
+		greater_than,
+		greater_or_equal,
+		less_than,
+		less_or_equal,
+		in_range,
+		valid_values,
+		length,
+		min_length,
+		max_length,
+		pattern;
+	}
+
+
+	/* hold the constraint evaluators for pairs of type/constraint.
+	 * If a pair is not present than the given constraint does not apply
+	 * to the type.
+	 */
+	private static Table<Type,Constraint,Evaluator> typeConstraintEvaluator =null;
+
+	public static Evaluator
+						getTypeConstraintEvaluator(Type theType, Constraint theConstraint) {
+		if (typeConstraintEvaluator == null) {
+			typeConstraintEvaluator = HashBasedTable.create();
+
+			typeConstraintEvaluator.put(CoreType.String, Constraint.equal,
+				(val,def,ctx) -> val.equals(getConstraintValue(def,Constraint.equal)));
+			typeConstraintEvaluator.put(CoreType.String, Constraint.valid_values,
+				(val,def,ctx) -> {
+						return ((List)getConstraintValue(def,Constraint.valid_values)).contains(val);
+			  });
+			typeConstraintEvaluator.put(CoreType.String, Constraint.length,
+				(val,def,ctx) -> ((String)val).length() == ((Number)getConstraintValue(def,Constraint.length)).intValue());
+			typeConstraintEvaluator.put(CoreType.String, Constraint.min_length, 
+				(val,def,ctx) -> ((String)val).length() >= ((Number)getConstraintValue(def,Constraint.min_length)).intValue());
+			typeConstraintEvaluator.put(CoreType.String, Constraint.max_length, 
+				(val,def,ctx) -> ((String)val).length() <= ((Number)getConstraintValue(def,Constraint.max_length)).intValue());
+			typeConstraintEvaluator.put(CoreType.String, Constraint.pattern,
+				(val,def,ctx) -> Pattern.compile((String)getConstraintValue(def,Constraint.pattern))
+																	.matcher((String)val)
+																		.matches());
+
+			typeConstraintEvaluator.put(CoreType.Integer, Constraint.equal,
+				(val,def,ctx) -> ((Integer)val).compareTo((Integer)getConstraintValue(def,Constraint.equal)) == 0);
+			typeConstraintEvaluator.put(CoreType.Integer, Constraint.greater_than,
+				(val,def,ctx) -> ((Integer)val).compareTo((Integer)getConstraintValue(def,Constraint.greater_than)) > 0);
+			typeConstraintEvaluator.put(CoreType.Integer, Constraint.greater_or_equal,
+				(val,def,ctx) -> ((Integer)val).compareTo((Integer)getConstraintValue(def,Constraint.greater_or_equal)) >= 0);
+			typeConstraintEvaluator.put(CoreType.Integer, Constraint.less_than,
+				(val,def,ctx) -> ((Integer)val).compareTo((Integer)getConstraintValue(def,Constraint.less_than)) < 0);
+			typeConstraintEvaluator.put(CoreType.Integer, Constraint.less_or_equal,
+				(val,def,ctx) -> ((Integer)val).compareTo((Integer)getConstraintValue(def,Constraint.less_or_equal)) <= 0);
+			typeConstraintEvaluator.put(CoreType.Integer, Constraint.in_range,
+				(val,def,ctx) -> { List<Integer> range = (List<Integer>)getConstraintValue(def, Constraint.in_range);
+													 return ((Integer)val).compareTo(range.get(0)) >= 0 &&
+																	((Integer)val).compareTo(range.get(1)) <= 0;
+												});
+			typeConstraintEvaluator.put(CoreType.Integer, Constraint.valid_values,
+				(val,def,ctx) -> ((List<Integer>)getConstraintValue(def, Constraint.valid_values)).contains((Integer)val));
+		
+//yaml parser represents yaml floats as java Double and we are even more tolerant as many double values
+//get represented as ints and the parser will substitute an Integer	
+			typeConstraintEvaluator.put(CoreType.Float, Constraint.equal,
+				(val,def,ctx) -> ((Number)val).doubleValue() == ((Number)getConstraintValue(def,Constraint.equal)).doubleValue());
+			typeConstraintEvaluator.put(CoreType.Float, Constraint.greater_than,
+				(val,def,ctx) -> ((Number)val).doubleValue() > ((Number)getConstraintValue(def,Constraint.greater_than)).doubleValue());
+			typeConstraintEvaluator.put(CoreType.Float, Constraint.greater_or_equal,
+				(val,def,ctx) -> ((Number)val).doubleValue() >= ((Number)getConstraintValue(def,Constraint.greater_or_equal)).doubleValue());
+			typeConstraintEvaluator.put(CoreType.Float, Constraint.less_than,
+				(val,def,ctx) -> ((Number)val).doubleValue() < ((Number)getConstraintValue(def,Constraint.less_than)).doubleValue());
+			typeConstraintEvaluator.put(CoreType.Float, Constraint.less_or_equal,
+				(val,def,ctx) -> ((Number)val).doubleValue() <= ((Number)getConstraintValue(def,Constraint.less_or_equal)).doubleValue());
+			typeConstraintEvaluator.put(CoreType.Float, Constraint.in_range,
+				(val,def,ctx) -> { List<Number> range = (List<Number>)getConstraintValue(def, Constraint.in_range);
+													 return ((Number)val).doubleValue() >= range.get(0).doubleValue() &&
+																	((Number)val).doubleValue() <= range.get(1).doubleValue();
+												});
+			typeConstraintEvaluator.put(CoreType.Float, Constraint.valid_values,
+				(val,def,ctx) -> ((List<Number>)getConstraintValue(def, Constraint.valid_values)).contains((Number)val));
+		}
+
+		Evaluator eval = typeConstraintEvaluator.get(theType, theConstraint);
+
+		return eval == null ? (expr,def,ctx) -> true
+												: eval;
+	}
+
+	
+	private static boolean stringValidValues(String theVal,
+																 					 List<String> theValidValues,
+																 					 Checker.CheckContext theCtx) {
+		if (!theValidValues.contains(theVal)) {
+			theCtx.addError("not a valid value: " + theVal + " not part of " + theValidValues, null);
+			return false;
+		}
+
+		return true;
+	}
+
+	public static final void main(String[] theArgs) {
+		Data.CoreType dt = Enum.valueOf(Data.CoreType.class, theArgs[0]);
+		System.out.println(theArgs[1] + " > " + dt.evaluator().eval(theArgs[1], null, null));
+	}
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Facet.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Facet.java
new file mode 100644
index 0000000..ea9fd48
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Facet.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker;
+
+/*
+ * Oddballs:
+ *  - requirements (a requirement does not have a type - i.e. is not based
+ *  on a Construct) and can target a node, a capability or both .. When present 
+ *  as a facet of another Construct it is also the only one represented as a
+ *  sequence so it will need special handling anyway.
+ */
+public enum Facet {
+    
+	inputs(Construct.Data),
+	outputs(Construct.Data),
+	properties(Construct.Data),
+	attributes(Construct.Data),
+ 	capabilities(Construct.Capability),
+ 	//requirements(Construct.Capability),//??
+ 	artifacts(Construct.Artifact),
+	interfaces(Construct.Interface);
+	/*
+  Node
+	Relationship
+	they can be considered as facets of the topology template ...
+	*/
+    
+	private Construct construct;
+
+	private Facet(Construct theConstruct) {
+		this.construct  = theConstruct;
+	}
+
+	public Construct construct() {
+		return this.construct;
+	}
+}
+
+
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Messages.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Messages.java
new file mode 100644
index 0000000..98158da
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Messages.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker;
+
+import java.text.MessageFormat;
+import java.util.ResourceBundle;
+import java.util.MissingResourceException;
+
+/*
+ * This class should be generated programatically based on the keys available in messages.properties
+ */
+public class Messages {
+
+	private ResourceBundle	messages;
+	
+	public Messages() {
+		try {
+			this.messages = ResourceBundle.getBundle("org/onap/tosca/checker/messages");
+		}
+		catch (MissingResourceException mrx) {
+			throw new RuntimeException("", mrx);
+		}
+
+		//check that the Message enum is in sync with the resource bundle
+	}
+
+	public String format(Message theMessage, Object[] theArgs) {
+		String message = this.messages.getString(theMessage.name());
+		if (message == null)
+			throw new RuntimeException("Un-available message: " + theMessage);
+ 
+		return MessageFormat.format(message, theArgs);
+	}
+
+	public enum Message {
+		EMPTY_TEMPLATE,
+		INVALID_CONSTRUCT_REFERENCE,
+		INVALID_TYPE_REFERENCE,
+		INVALID_TEMPLATE_REFERENCE,
+		INVALID_INTERFACE_REFERENCE,
+		INVALID_FACET_REFERENCE,
+		INCOMPATIBLE_REQUIREMENT_TARGET
+	}
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Paths.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Paths.java
new file mode 100644
index 0000000..2cedaca
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Paths.java
@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker;
+
+import java.util.Map;
+import java.util.HashMap;
+import java.util.Iterator;
+
+import org.apache.commons.jxpath.JXPathContext;
+import org.apache.commons.jxpath.JXPathException;
+
+import org.onap.tosca.checker.annotations.Catalogs;
+
+/*
+ * Facilitates processing of catalog information through xpath expressions.
+ * In development.
+ */
+public class Paths {
+
+	private Map<Target, JXPathContext>	paths = new HashMap<Target, JXPathContext>();
+	private JXPathContext								types = JXPathContext.newContext(new HashMap());
+
+	@Catalogs(path="/")
+	public void catalog_root(Map theDefinition, Checker.CheckContext theContext) {
+		paths.put(theContext.target(), JXPathContext.newContext(theContext.target().getTarget()));
+		theDefinition
+			.forEach((k,v) -> { if (k.toString().endsWith("_types"))
+														((Map)types.getContextBean()).merge(k, v, (v1, v2) -> { ((Map)v1).putAll((Map)v2);
+																																										return v1; 
+																																									});
+												});
+	}
+	
+	public Object resolve(Target theTarget, String thePath) {
+		return paths.get(theTarget).getValue(thePath);
+	}
+	
+	public Object resolve(String thePath) {
+		return types.getValue(thePath);
+	}
+
+	/* */
+	public String nodeType(String theNodeType) {
+		return (String)resolve("/node_types/" + theNodeType);
+	}
+
+	public Map nodeTypeInterface(String theNodeType, String theInterfaceName) {
+		return (Map)resolve("/node_types/" + theNodeType + "/interfaces/" + theInterfaceName);
+	}
+	
+	public String nodeTypeInterfaceType(String theNodeType, String theInterfaceName) {
+		return (String)resolve("/node_types/" + theNodeType + "/interfaces/" + theInterfaceName + "/type");
+	}
+
+	/* */
+	public Map interfaceType(String theInterfaceType) {
+		return (Map)resolve("/interface_types/" + theInterfaceType);
+	}
+
+	//this will also resolve 'metadata', 'derived_from', version and other common entries as operations
+	public Map interfaceTypeOperation(String theInterfaceType, String theOperationName) {
+		return (Map)resolve("/interface_types/" + theInterfaceType + "/" + theOperationName);
+	}
+
+	/* node templates */
+	public String nodeTemplateType(Target theTarget, String theNodeName) {
+		return (String)resolve(theTarget, "/topology_template/node_templates/" + theNodeName + "/type");
+	}
+
+	public Map nodeTemplateInterface(Target theTarget, String theNodeName, String theInterfaceName) {
+		return (Map)resolve(theTarget, "/topology_template/node_templates/" + theNodeName + "/interfaces/" + theInterfaceName);
+	}
+
+	public Map nodeTemplateInterfaceOperation(
+								Target theTarget, String theNodeName, String theInterfaceName, String theOperationName) {
+		return (Map)resolve(theTarget, "/topology_template/node_templates/" + theNodeName + "/interfaces/" + theInterfaceName + "/" + theOperationName);
+	}
+
+
+	/* */
+	public Map nodeTypeInterfaceOperation(String theNodeType, String theInterfaceName, String theOperationName) {
+		return (Map)resolve("/node_types/" + theNodeType + "/interfaces/" + theInterfaceName + "/" + theOperationName);
+	}
+	
+	
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Report.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Report.java
new file mode 100644
index 0000000..bce0729
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Report.java
@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker;
+
+import java.io.IOException;
+
+import java.util.LinkedList;
+import java.util.Collections;
+
+import org.yaml.snakeyaml.error.MarkedYAMLException;
+import kwalify.ValidationException;
+
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonProcessingException;
+
+/**
+ * Represents a collection of errors that occured during one of the stages
+ * of the checker: yaml parsing, yaml validation (tosca syntax), tosca checking
+ */
+/*
+ * This needs some re-thinking: while it is useful to have all original errors introducing
+ * the custom json conversion (just to help the service) is not great either.
+ * I was torn between this approach or creating a custom deserializer and object mapper (which
+ * would have kept all the customized serialization in the service but then the error analysis
+ * would be duplicated there too ..).  
+ */
+@JsonSerialize(contentUsing=org.onap.tosca.checker.Report.ReportEntrySerializer.class)
+public class Report<T extends Throwable> extends LinkedList<T> {
+
+	public Report() {
+	}
+
+	public Report(T[] theErrors) {
+		Collections.addAll(this, theErrors);
+	}
+
+	public boolean hasErrors() {
+		return !this.isEmpty();
+	}
+
+	public boolean addOnce(T theError) {
+		for (T e: this) {
+			if (e.getMessage().equals(theError.getMessage()))
+				return false;
+		}
+		return add(theError);
+	}
+
+	public String toString() {
+    StringBuilder sb = new StringBuilder(this.size() + " errors");
+    for (Throwable x: this) {
+      sb.append("\n")
+				.append("[")
+        .append(location(x))
+        .append("] ")
+				.append(x.getMessage());
+				if (x.getCause() != null) {
+					sb.append("\n\tCaused by:\n")
+          	.append(x.getCause());
+				}
+    }
+		sb.append("\n");
+		return sb.toString();
+	}
+
+	private static String location(Throwable theError) {
+		if (theError instanceof MarkedYAMLException) {
+			MarkedYAMLException mx = (MarkedYAMLException)theError;
+			return "line " + mx.getProblemMark().getLine() + ", column " + mx.getProblemMark().getColumn();
+		}
+		if (theError instanceof ValidationException) {
+      ValidationException vx = (ValidationException)theError;
+      return vx.getPath();
+    }
+		if (theError instanceof TargetError) {
+    	TargetError tx = (TargetError)theError;
+      return tx.getLocation();
+		}
+		return "unknown"; 
+	}
+
+
+	public static class ReportEntrySerializer extends StdSerializer<Throwable> {
+		
+		public ReportEntrySerializer() {
+			super(Throwable.class);
+		}
+
+    @Override
+    public void serialize(Throwable theError, JsonGenerator theGenerator, SerializerProvider theProvider) 
+																												      throws IOException, JsonProcessingException {
+      theGenerator.writeStartObject();
+      theGenerator.writeStringField("location", location(theError));
+      theGenerator.writeStringField("message", theError.getMessage());
+			if (theError.getCause() != null)
+      	theGenerator.writeStringField("cause", theError.getCause().toString());
+      theGenerator.writeEndObject();
+    }
+	}
+}
+
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Repository.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Repository.java
new file mode 100644
index 0000000..66c37af
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Repository.java
@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker;
+
+
+import java.net.URI;
+import java.net.URL;
+import java.net.MalformedURLException;
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import java.util.Map;
+
+/**
+ * Represents a 'container' of (yaml) TOSCA documents
+ */
+public abstract class Repository {
+
+	protected static Logger log =
+			Logger.getLogger("com.att.research.is.tosca.yaml.Repository");
+
+	private String 				name,
+												description;
+	protected URI					 	rootURI;
+	protected Map 					credential;	//TOSCA type tosca.datatype.Credential
+
+	public Repository(String theName, URI theRoot) {
+		this.name = theName;
+		this.rootURI = theRoot;
+	}
+
+	public String getName() {
+		return this.name;
+	}
+
+	public URI getRoot() {
+		return this.rootURI;
+	}
+
+	/** optional */
+	public abstract Iterable<Target> targets();
+
+	/** */
+	public abstract Target resolve(URI theURI);
+
+	@Override
+	public String toString() {
+		return "Repository " + this.name + " at " + this.rootURI;
+	}
+}
+
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Stage.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Stage.java
new file mode 100644
index 0000000..416a533
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Stage.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker;
+
+/*
+ * The Target processing stages 
+ */
+public enum Stage {
+  
+	located, /* not really used as we do not track a Target that we cannot locate */ 
+	parsed,  /* yaml parsing succesfully completed */
+	validated, /* syntax check succesfully completed: document is compliant to yaml tosca grammar */
+	cataloged, /* all the constructs have been cataloged */
+	checked; /* 'semantic' checking completed */
+	
+	private static final Stage[] stages = values();
+
+	public Stage next() {
+		return stages[ordinal() + 1];
+	}
+}
+
+
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Target.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Target.java
new file mode 100644
index 0000000..c21593b
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Target.java
@@ -0,0 +1,109 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker;
+
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.io.BufferedReader;
+import java.io.IOException;
+
+import java.net.URI;
+import java.net.URL;
+import java.net.MalformedURLException;
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * Represents a yaml document to be parsed/validated/checked.
+ * A Target's scope is the checker that is processing it.
+ */
+public class Target {
+
+	private static Logger log =
+			Logger.getLogger("com.att.research.is.tosca.yaml.Target");
+
+	private String 	name;
+	private URI			location;
+	//while it is convenient having the information below in here I am conflicted about it
+	//as it represents processing state
+	private Object 	target;								 //this is the parsed form of the target
+	private Stage		stage = Stage.located; //the processinf stage this target has reached
+	private	Report	report = new Report(); //collects the errors related to this target
+
+	public Target(String theName, URI theLocation) {
+		this.name = theName;
+		this.location = theLocation;
+	}
+
+	public String getName() {
+		return this.name;
+	}
+
+	public URI getLocation() {
+		return this.location;
+	}
+
+	public Report getReport() {
+		return this.report;
+	}
+
+	public void report(Throwable theError) {
+		this.report.add(theError); 
+	}
+	
+	public void report(String theErrMsg) {
+		this.report.add(new Exception(theErrMsg)); 
+	}
+
+	public void setTarget(Object theTarget) {
+		this.target = theTarget;
+	}
+
+	public Object getTarget() {
+		return this.target;
+	}
+
+	public Stage getStage() {
+		return this.stage;
+	}
+
+	public void setStage(Stage theStage) {
+		if (theStage.ordinal() <= this.stage.ordinal())
+			throw new IllegalArgumentException("Stage can only be set forward.");
+
+		this.stage = theStage;
+	}
+
+	public void nextStage() {
+		setStage(this.stage.next());
+	}
+
+	/*
+	 * @return a reader for the source or null if failed
+	 */
+	public Reader open() throws IOException {
+
+    return new BufferedReader(
+						new InputStreamReader(
+          		this.location.toURL().openStream()));
+	}
+
+	public String toString() {
+		//return String.format("Target %s (%.20s ...)", this.location, this.target == null ? "" : this.target.toString());
+		return String.format("Target %s at %s", this.name, this.location);
+
+	}
+}
+
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/TargetError.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/TargetError.java
new file mode 100644
index 0000000..917ec3f
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/TargetError.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker;
+
+
+/**
+ * A target error represents an error in target the resource being checked.
+ * We only represent it as a Throwable because the libraries that perform parsing and syntax validation
+ * represent their errors as such ..
+ */
+public class TargetError extends Throwable {
+
+	/*
+	public static enum Level {
+		error,
+		warning	
+	}
+	*/
+
+  private String		location; //we might need an more detailed representation
+															//here: it could be a YAML document jpath or
+															//document location (line).
+  private String		target;
+
+  public TargetError(String theTarget, String theLocation, String theMessage, Throwable theCause) {
+		super(theMessage, theCause);
+    this.target = theTarget;
+		this.location = theLocation;
+  }
+
+  public TargetError(String theTarget, String theLocation, String theMessage) {
+    this(theTarget, theLocation, theMessage, null);
+  }
+
+	public String getTarget() {
+		return this.target;
+	}
+
+	public String getLocation() {
+		return this.location;
+	}
+
+
+}
+
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/TargetLocator.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/TargetLocator.java
new file mode 100644
index 0000000..920e1a6
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/TargetLocator.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker;
+
+import java.net.URI;
+
+/**
+ * Used to locate a document that needs to be processed by the checker
+ */
+public interface TargetLocator {
+	
+	/** */
+	public boolean addSearchPath(URI theURI); 
+
+	/** */
+	public boolean addSearchPath(String thePath);
+
+	/** */
+	public Iterable<URI> searchPaths();
+	
+	/** */
+	public Target resolve(String theName);
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Workflows.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Workflows.java
new file mode 100644
index 0000000..3f6a445
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/Workflows.java
@@ -0,0 +1,287 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker;
+
+import java.util.Map;
+import java.util.List;
+import java.util.Iterator;
+
+import org.onap.tosca.checker.annotations.Checks;
+
+/**
+ * Workflows checking isolated as it is of significant size. Showcases the way checking can be added to the core
+ * checker through annotations.
+ */
+@Checks
+public class Workflows {
+
+	@Checks(path="/topology_template/workflows")
+	public void check_workflows(Map theDefinition, Checker.CheckContext theContext) {
+
+		theContext.enter("workflows", null, theDefinition);
+	
+		try {
+			if(!theContext.checker().checkDefinition("workflows", theDefinition, theContext))
+		 		return;
+
+  	  for (Iterator<Map.Entry<String,Map>> i = theDefinition.entrySet().iterator(); i.hasNext(); ) {
+    	  Map.Entry<String,Map> e = i.next();
+				check_workflow_definition(e.getKey(), e.getValue(), theContext);
+    	}
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+
+
+	public void check_workflow_definition(String theName, Map theDef, Checker.CheckContext theContext) {
+		
+		theContext.enter("workflow", Construct.Workflow);
+
+		if (theDef.containsKey("inputs")) {
+    	theContext
+				.checker()
+					.check_properties((Map<String,Map>)theDef.get("inputs"), theContext);
+    }
+
+		if (theDef.containsKey("preconditions")) {
+			check_workflow_preconditions_definition((List<Map>)theDef.get("preconditions"), theContext);
+		}
+
+		if (theDef.containsKey("steps")) {
+			check_workflow_steps_definition((Map<String, Map>)theDef.get("steps"), theContext);
+		}
+
+		theContext.exit();
+	}
+  	  
+
+	public void check_workflow_steps_definition(Map theSteps, Checker.CheckContext theContext) {
+		
+		theContext.enter("steps");
+
+		try {
+			for (Iterator<Map.Entry<String,Map>> i = theSteps.entrySet().iterator(); i.hasNext(); ) {
+  	  	Map.Entry<String,Map> e = i.next();
+				check_workflow_step_definition(e.getKey(), e.getValue(), theContext);
+    	}
+		}
+		finally {
+			theContext.exit();
+		}
+
+	}
+
+	public void check_workflow_step_definition(String theName, Map theDef, Checker.CheckContext theContext) {
+
+		theContext.enter(theName, null, theDef);
+		try {
+			//target
+			check_target_definition(theDef, theContext);
+
+			//operation_host
+
+			//filter: sequence of constraints with workflow assertion definitions (see section 3.5.18)
+			//where the keys are attribute names: representing the name of an attribute defined on the assertion context
+			//entity (node instance, relationship instance, group instance) 
+ 			//we could verify that all th eattributes ae defined .. how accurate can that be 
+
+			//activities
+			List<Map> activities = (List)theDef.get("activities");
+			if (activities != null) {
+				for (Map activity: activities) {
+					check_workflow_step_activity_definition(activity, theContext);
+				}
+			}
+
+			List successSteps = (List)theDef.get("on_success");
+			List failureSteps = (List)theDef.get("on_failure");
+			if (successSteps != null || failureSteps != null) {
+				Map steps = (Map)theContext.catalog().getTemplate(theContext.target(),
+														 														  Construct.Workflow,
+																													theContext.enclosingConstruct(Construct.Workflow).name())
+																								.get("steps");
+
+				if (successSteps != null) {
+					for (Object successStep: successSteps) {
+						if (!steps.containsKey(successStep)) {
+							theContext.addError("The 'on_success' step " + successStep + " was not declared", null);
+						}
+					}
+				}
+
+				if (failureSteps != null) {
+					for (Object failureStep: failureSteps) {
+						if (!steps.containsKey(failureStep)) {
+							theContext.addError("The 'on_failure' step " + failureStep + " was not declared", null);
+						}
+					}
+				}
+			}
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+
+	public void check_workflow_preconditions_definition(List<Map> thePreconditions, Checker.CheckContext theContext) {
+		
+		theContext.enter("preconditions");
+
+		try {
+			for (Map precondition: thePreconditions) {
+				check_workflow_precondition_definition(precondition, theContext);
+    	}
+		}
+		finally {
+			theContext.exit();
+		}
+	}
+
+	public void check_workflow_precondition_definition(Map theDef, Checker.CheckContext theContext) {
+	
+		Map targetDef = check_target_definition(theDef, theContext);
+		if (targetDef != null) {
+			List<Map> condDef = (List<Map>)theDef.get("condition");
+			if (condDef != null) {
+				check_condition_clause_definition(targetDef, condDef, theContext);
+			}
+		}
+	}
+
+	public void check_workflow_step_activity_definition(Map theDef, Checker.CheckContext theContext) {
+		if (theDef.size() != 1)
+			theContext.addError("An activity has only one entry", null);
+
+		//only one entry expected
+		String delegate = (String)theDef.get("delegate");
+		if (delegate != null) {
+			//not clear to me what this is:  a reference to a declarative workflow?
+		}
+
+		String state = (String)theDef.get("set_state");
+		if (state != null) {
+		}
+
+		String operation = (String)theDef.get("call_operation");
+		if (operation != null) {
+			int pos = operation.lastIndexOf('.');
+			if (pos < 0) {
+				theContext.addError("Invalid 'operation_call' statement", null);
+			}
+			else {
+				String interfaceName = operation.substring(0, pos),
+							 interfaceOp = operation.substring(pos+1);
+
+				//we expect the enclosing to be the workflow step, where the target is specified
+				String stepTarget = (String)((Map)theContext.enclosing().info()).get("target");
+				Paths  paths = theContext.checker().getHandler(Paths.class);
+				Map		 opDef = null;
+		
+				//look in the node template
+				if (null == (opDef = paths.nodeTemplateInterfaceOperation(
+																										theContext.target(),
+																										stepTarget,
+																										interfaceName,
+																										interfaceOp))) {
+					//look in the node type
+					if (null == (opDef = paths.nodeTypeInterfaceOperation(
+																								paths.nodeTemplateType(theContext.target(), stepTarget),
+																								interfaceName,
+																								interfaceOp))) {
+						
+						//look into the interface type definition, if the node has an interface with the given name
+						if (null == 
+									(opDef = paths.interfaceTypeOperation(
+																paths.nodeTypeInterfaceType(paths.nodeTemplateType(theContext.target(), stepTarget),
+																												 		interfaceName),
+																interfaceOp))) {
+							theContext.addError("Step target node " + stepTarget + " does not have a " + interfaceName + " with operation " + interfaceOp, null);
+						}
+					}
+				}
+
+				System.out.println("*** opDef: " + opDef);
+			}
+		}
+
+		String workflow = (String)theDef.get("inline");
+		if (workflow != null && !((Map)theContext.enclosingElement("workflows").info()).containsKey(workflow)) {
+			theContext.addError("Activity 'inline'  " + workflow + " was not declared", null);
+		}
+	}
+
+	/* it would have been great to be ab le to convey in the return value the type of construct
+	 */
+	protected Map check_target_definition(Map theDef, Checker.CheckContext theContext) {
+			
+		String 		target = (String)theDef.get("target");
+		Construct targetConstruct = null;
+		Map				targetDef = null;
+
+		if ((targetDef = theContext.catalog().getTemplate(theContext.target(), Construct.Group, target)) != null) {
+			targetConstruct = Construct.Group;
+		}
+		else if ((targetDef = theContext.catalog().getTemplate(theContext.target(), Construct.Node, target)) != null) {
+			targetConstruct = Construct.Node;
+		}
+		else {
+			theContext.addError("The 'target' entry must contain a reference to a node template or group template, '" + target + "' is none of those", null);
+		}
+
+		String targetRelationship = (String)theDef.get("target_relationship");
+		if (targetRelationship != null) {
+			if (targetConstruct.equals(Construct.Node)) {
+				//'The optional name of a requirement of the target in case the step refers to a relationship rather than a node or group'
+				if (null == theContext.catalog().getRequirementDefinition(Construct.Node, 
+																																	(String)targetDef.get("type"),
+																																	targetRelationship)) {
+					theContext.addError("The 'target' (" + target + ") has no requirement '" + targetRelationship + "', as indicated by 'targetRelationship'", null);
+				}
+			}
+			else {
+				theContext.addError("The 'target_relationship' is only applicable if the 'target' (" + target + ") is a node template (which it is not)", null);
+			}
+		}
+
+		return targetDef;
+	}
+
+	protected boolean check_condition_clause_definition(Map theTargetDefinition,
+																											List<Map> theConditionDef,
+																											Checker.CheckContext theContext) {
+		boolean res = true;
+
+		for (Map clause: theConditionDef) {
+			Map.Entry clauseEntry = (Map.Entry)clause.entrySet().iterator().next();
+			String	  clauseType = (String)clauseEntry.getKey();
+
+			if ("and".equals(clauseType) || "or".equals(clauseType)) {
+				res &= check_condition_clause_definition(theTargetDefinition, (List<Map>)clauseEntry.getValue(), theContext);
+			}
+			else if ("assert".equals(clauseType)) {
+				List<Map> assertions = (List<Map>)clauseEntry.getValue();
+				for (Map assertion: assertions) {
+					//expected to be a one entry map
+					for (Object attributeName: assertion.keySet()) {
+						//the attribute must be defined in the given Target .. but there are also exposed built-in attributes (such as 'state') that we are not aware of
+					}
+				}
+			}
+		}
+
+		return res;
+	}
+}
+
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/annotations/Catalogs.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/annotations/Catalogs.java
new file mode 100644
index 0000000..829d756
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/annotations/Catalogs.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.annotations;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Target;
+
+
+/**
+ * Marks a method as a processing step during the cataloging phase. Allows for custom cataloging of (any) tosca
+ * construct information.
+ * The expected signature of a cataloging processing function is:
+ *	param theDef	of type matching the representation of the expected/processed construct
+ *	param theContext exposes the processing state of the checker
+ *
+ * <div>
+ * {@code
+ * 	 package org.onap.tosca.myaddons;
+ *
+ *   import org.onap.tosca.checker.annotations.Catalogs;
+ *
+ *   public class MyToscaCatalog {
+ *    ..
+ *     @Catalogs(path="/node_types")
+ *     public void catalog_node_types(
+ *									Map<String, Map> theDefinitions, CheckContext theContext) {
+ *        //doing my thing
+ *	   }
+ *   }
+ * </div>
+ *
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.METHOD}) 
+public @interface Catalogs {
+  String path() default "/";
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/annotations/Checks.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/annotations/Checks.java
new file mode 100644
index 0000000..856ac1b
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/annotations/Checks.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.annotations;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Target;
+
+
+/**
+ * Marks a method as a processing step during the checking phase. Allows for additional checking to be 'plugged' in.
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.TYPE, ElementType.METHOD}) 
+/**
+ * Marks a method as participating in the consistency checking stage. The method is expected to have the following
+ * signature:
+ *	param theDef type of expected representation of the construct's information, for example Map<String,Map> for
+ * 			node_types or List<Map> for requirements
+ *  param theContext	CheckContext instance exposing the checker state
+ * 
+ * Note: currently not used at type level
+ */
+/* The iffy part: as a type annotaton we do not need a path or a version specification,
+   as a method annotation it is mandatory (cannot be the default) 
+	 We could forsee that a version indication at type level would cover all check handler within the type
+ */
+public @interface Checks {
+  String path() default "/";
+	String[] version() default { "1.0", "1.0.0", "1.1", "1.1.0" };
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/annotations/Validates.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/annotations/Validates.java
new file mode 100644
index 0000000..f34a9fc
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/annotations/Validates.java
@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.annotations;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Target;
+
+
+/**
+ * Marks a method as a processing step during the validation phase (grammar rules checking).
+ * The expected signature of a method so annotated is:
+ * 	param theObject the POJO currently being subject to validation
+ *  param theRule kwalify yaml syntax rule representation
+ *	param theContext kwalify validation context exposing the state of the validator
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.TYPE, ElementType.METHOD}) 
+public @interface Validates {
+
+	public static enum Timing {
+		pre,
+		post
+	}
+
+	/* empty string means 'all rules' */
+  String rule();
+
+	Validates.Timing timing();
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/annotations/package-info.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/annotations/package-info.java
new file mode 100644
index 0000000..e7b268a
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/annotations/package-info.java
@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+
+/**
+ * Contains the definition of the annotations used to mark methods used in processing a TOSCA template, one annotation
+ * for each stage (not for locate and parsed: the location process is done through org.onap.tosca.checker.Locator and 
+ * parsing is currently built in).
+ *
+ * The checker {@link org.onap.tosca.checker.Checker Checker} scans the classpath for classes with methods annotated 
+ * accordingly to annotations in this package (currently we scan packages prefixed with org.onap.tosca).
+ * 
+ * At different stages the checker will delegate processing to this annotated methods. 
+ *
+ * {@link org.onap.tosca.checker.annotations.Validates Validates} marks a method as part of the validation stage, i.e.
+ * syntax checking. It requires the indication of the grammar rule it intends to add validation to and wether it
+ * performs pre or post processing.  
+ *
+ * {@link org.onap.tosca.checker.annotations.Checks Checks} marks a method as part of the consistency checks stage.
+ * A method such annotated will be invoked when the processing reaches the document path indicated in the annotation.
+ * A document path follows the strcture of the TOSCA yaml document, for example:
+ *		/node_types/some_node_type
+ *		/topology_template/node_templates
+ * Note that current implementation works by delegation down the hierachical structure of the document. If no processor
+ * is in place for /topology_templates/ or the one(s) in place do not delegate any further then a processor for
+ * /topology_template/node_templates will not get involved. The framework only attempts the invocation of first level
+ * (hierachically speaking) checks.
+ *
+ * {@link org.onap.tosca.checker.annotations.Catalogs Catalogs} marks a method as part of the cataloging stage, i.e.
+ * the storage/indexing (of some sort, it does not really need to be storing) of a construct that has been validated.
+ * Same as with {@link org.onap.tosca.checker.annotations.Checks Checks} the scope of a Cataloger is determined through
+ * a document path specification.
+ *
+ * A third party can provide its own processing (by using these annotations) and perform custom verifications, indexing
+ * for special post-processing, etc. 
+ */
+
+package org.onap.tosca.checker.annotations;
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Artifact.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Artifact.java
new file mode 100644
index 0000000..8d67f0f
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Artifact.java
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+/**
+ * Artifact definition, spec section 3.5.6
+ */
+public interface Artifact extends TOSCAObject<Artifact> {
+
+	public String name();
+
+	public String type();
+	
+	public String description();
+	
+	public String file();
+	
+	public String repository();
+	
+	public String deploy_path();
+	
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/ArtifactType.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/ArtifactType.java
new file mode 100644
index 0000000..798a550
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/ArtifactType.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.List;
+
+/**
+ * Artifact type definition, spec section 3.6.4
+ */
+public interface ArtifactType extends TOSCAObject<ArtifactType> {
+
+	public String name();
+
+	public String derived_from();
+	
+	public String description();
+	
+	public String version();
+	
+	public default Metadata metadata() {
+		return (Metadata)proxy("metadata", Metadata.class);
+	}
+	
+	public String mime_type();
+	
+	public List<String> file_ext();
+
+	public default Properties properties() {
+		return (Properties)proxy("properties", Properties.class);
+	}
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/ArtifactTypes.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/ArtifactTypes.java
new file mode 100644
index 0000000..d714cae
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/ArtifactTypes.java
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface ArtifactTypes extends TOSCAMap<ArtifactType> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Artifacts.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Artifacts.java
new file mode 100644
index 0000000..7c22eac
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Artifacts.java
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface Artifacts extends TOSCAMap<Artifact> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Attribute.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Attribute.java
new file mode 100644
index 0000000..0515f78
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Attribute.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+/**
+ */
+public interface Attribute extends TOSCAObject<Attribute> {
+
+	public String name();
+
+	public String type();
+	
+	public String description();
+	
+	public default Object _default() {
+		return info().get("default");
+	}
+
+	public Boolean required();
+	
+	public String status();
+
+	public String entry_schema();
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Attributes.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Attributes.java
new file mode 100644
index 0000000..d5ee2ca
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Attributes.java
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface Attributes extends TOSCAMap<Attribute> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/AttributesAssignments.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/AttributesAssignments.java
new file mode 100644
index 0000000..70ac163
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/AttributesAssignments.java
@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+/*
+ * A simple representation of the attribute value assignments, spec section 3.5.11
+ */
+public interface AttributesAssignments extends TOSCAObject<AttributesAssignments> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Capabilities.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Capabilities.java
new file mode 100644
index 0000000..31d0e45
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Capabilities.java
@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+/**
+ * Collection of type specific capability definitions (spec section 3.6.2) 
+ */
+public interface Capabilities extends TOSCAMap<Capability> {
+
+}
+
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/CapabilitiesAssignments.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/CapabilitiesAssignments.java
new file mode 100644
index 0000000..d0f4200
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/CapabilitiesAssignments.java
@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+/**
+ * Collection of template specific capability assignment (spec section 3.7.2) 
+ */
+public interface CapabilitiesAssignments extends TOSCAMap<CapabilityAssignment> {
+
+}
+
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Capability.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Capability.java
new file mode 100644
index 0000000..72df0b7
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Capability.java
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.List;
+
+/*
+ * Type specific capability definition, spec section 3.6.2
+ */
+public interface Capability extends TOSCAObject<Capability> {
+
+	/**
+	 * The required name of the Capability Type the capability definition is based upon.
+   */
+	public String type();
+
+	/**
+	 * The optional description of the Capability definition.
+	 */	
+	public String description();
+
+	/**
+	 * An optional list of one or more valid names of Node Types that are supported as valid sources of any 
+	 * relationship established to the declared Capability Type.
+	 */
+	public List<String> valid_source_types();
+
+	/**
+	 * The optional minimum and maximum occurrences for the capability.
+	 * By default, an exported Capability should allow at least one relationship to be formed with it with a
+	 * maximum of UNBOUNDED relationships.
+	 */
+	public default Range occurences() {
+		return (Range)proxyList("occurences", Range.class);
+	}
+
+	/**
+	 * An optional list of property definitions for the Capability definition.
+	 */
+	public default Properties properties() {
+		return (Properties)proxy("properties", Properties.class);
+	}
+
+	/**
+	 * An optional list of attribute definitions for the Capability definition.
+	 */
+	public default Attributes attributes() {
+		return (Attributes)proxy("attributes", Attributes.class);
+	}
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/CapabilityAssignment.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/CapabilityAssignment.java
new file mode 100644
index 0000000..1c49dbe
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/CapabilityAssignment.java
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.List;
+
+/*
+ * Type specific capability definition, spec section 3.7.1
+ */
+public interface CapabilityAssignment extends TOSCAObject<CapabilityAssignment> {
+
+	/** */
+	public String name();
+
+	/**
+	 * An optional list of property definitions for the Capability definition.
+	 */
+	public default PropertiesAssignments properties() {
+		return (PropertiesAssignments)proxy("properties", PropertiesAssignments.class);
+	}
+
+	/**
+	 * An optional list of attribute definitions for the Capability definition.
+	 */
+	public default AttributesAssignments attributes() {
+		return (AttributesAssignments)proxy("attributes", AttributesAssignments.class);
+	}
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/CapabilityType.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/CapabilityType.java
new file mode 100644
index 0000000..64808d1
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/CapabilityType.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.List;
+
+public interface CapabilityType extends TOSCAObject<CapabilityType> {
+
+	public String name();
+
+	public String derived_from();
+	
+	public String description();
+
+	public String version();
+	
+	public List<String> valid_source_types();
+
+	public default Properties properties() {
+		return (Properties)proxy("properties", Properties.class);
+	}
+
+	public default Attributes attributes() {
+		return (Attributes)proxy("attributes", Attributes.class);
+	}
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/CapabilityTypes.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/CapabilityTypes.java
new file mode 100644
index 0000000..3567afe
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/CapabilityTypes.java
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface CapabilityTypes extends TOSCAMap<CapabilityType> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Constraint.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Constraint.java
new file mode 100644
index 0000000..03c8d20
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Constraint.java
@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+/**
+ * constraint definition, spec section 3.6.6
+ */
+public interface Constraint extends TOSCAObject<Constraint> {
+
+	public Constraint.Type name();
+
+	/* this is a one entry map so here we pick the single 
+	 */
+	public default Object expression() {
+		return info().values().iterator().next();
+	}
+
+	public enum Type {
+		equal,
+		greater_than,
+		greater_or_equal,
+		less_than,
+		less_or_equal,
+		in_range,
+		valid_values,
+		length,
+		min_length,
+		max_length,
+		pattern
+	}
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Constraints.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Constraints.java
new file mode 100644
index 0000000..8413cd7
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Constraints.java
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface Constraints extends TOSCASeq<Constraint> {
+
+}
+
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/DataType.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/DataType.java
new file mode 100644
index 0000000..941695c
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/DataType.java
@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+/**
+ * Data type definition, spec section 3.6.6
+ */
+public interface DataType extends TOSCAObject<DataType> {
+
+	public String name();
+
+	public String derived_from();
+	
+	public String description();
+	
+	public String version();
+	
+	public default Metadata metadata() {
+		return (Metadata)proxy("metadata", Metadata.class);
+	}
+
+	public default Properties properties() {
+		return (Properties)proxy("properties", Properties.class);
+	}
+
+	public default Constraints constraints() {
+		return (Constraints)proxy("constraints", Constraints.class);
+	}
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/DataTypes.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/DataTypes.java
new file mode 100644
index 0000000..10b343a
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/DataTypes.java
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface DataTypes extends TOSCAMap<DataType> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/EntrySchema.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/EntrySchema.java
new file mode 100644
index 0000000..3aebaab
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/EntrySchema.java
@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+/**
+ * Used in data type, property, input and so on definitions, see spec section  
+ */
+public interface EntrySchema extends TOSCAObject<EntrySchema> {
+
+	public String type();
+
+	public String description();
+
+	public default Constraints constraints() {
+		return (Constraints)proxy("constraints", Constraints.class);
+	}
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Group.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Group.java
new file mode 100644
index 0000000..9e530c1
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Group.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.List;
+
+/**
+ * Spec section 3.7.5
+ */
+public interface Group extends TOSCAObject<Group> {
+
+	public String name();
+
+	public String type();
+	
+	public String description();
+	
+	public default Metadata metadata() {
+		return (Metadata)proxy("metadata", Metadata.class);
+	}
+
+	public default PropertiesAssignments properties() {
+		return (PropertiesAssignments)proxy("properties", PropertiesAssignments.class);
+	}
+	
+	public default TemplateInterfaces interfaces() {
+		return (TemplateInterfaces)proxy("interfaces", TemplateInterfaces.class);
+	}
+
+	public List<String> members();
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/GroupType.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/GroupType.java
new file mode 100644
index 0000000..acaea03
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/GroupType.java
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.List;
+
+/**
+ * Group type definition, spec section 3.6.11
+ */
+public interface GroupType extends TOSCAObject<GroupType> {
+
+	public String name();
+
+	public String derived_from();
+	
+	public String description();
+	
+	public String version();
+	
+	public default Metadata metadata() {
+		return (Metadata)proxy("metadata", Metadata.class);
+	}
+	
+	public List<String> members();
+
+	public default Properties properties() {
+		return (Properties)proxy("properties", Properties.class);
+	}
+
+	public default Attributes attributes() {
+		return (Attributes)proxy("attributes", Attributes.class);
+	}
+
+	public default TypeInterfaces interfaces() {
+		return (TypeInterfaces)proxy("interfaces", TypeInterfaces.class);
+	}
+
+	public default Requirements requirements() {
+		return (Requirements)proxy("requirements", Requirements.class);
+	}
+
+	public default Capabilities capabilities() {
+		return (Capabilities)proxy("capabilities", Capabilities.class);
+	}
+	
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/GroupTypes.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/GroupTypes.java
new file mode 100644
index 0000000..8254af1
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/GroupTypes.java
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface GroupTypes extends TOSCAMap<GroupType> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Groups.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Groups.java
new file mode 100644
index 0000000..d6f770a
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Groups.java
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface Groups extends TOSCAMap<Group> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Import.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Import.java
new file mode 100644
index 0000000..2e7edf8
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Import.java
@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+/**
+ * Import defintion, see section 
+ */
+public interface Import extends TOSCAObject<Import> {
+
+	public String name();
+
+	public String file();
+
+	public String repository();
+	
+	public String namespace_uri();
+	
+	public String namespace_prefix();
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Imports.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Imports.java
new file mode 100644
index 0000000..3aed669
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Imports.java
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface Imports extends TOSCAMap<Import> {
+
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Input.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Input.java
new file mode 100644
index 0000000..e636d90
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Input.java
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+/**
+ * Same as property definition
+ */
+public interface Input extends TOSCAObject<Input> {
+
+	public String name();
+
+	public String type();
+
+	public String description();
+
+	public default Object _default() {
+		return info().get("default");
+	}
+
+	public boolean required();
+
+	public Status status();
+
+	public default Constraints constraints() {
+		return (Constraints)proxy("constraints", Constraints.class);
+	}
+
+	public default EntrySchema entry_schema() {
+		return (EntrySchema)proxy("entry_schema", EntrySchema.class);
+	}
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Inputs.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Inputs.java
new file mode 100644
index 0000000..1f19079
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Inputs.java
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface Inputs extends TOSCAMap<Input> {
+
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/InterfaceType.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/InterfaceType.java
new file mode 100644
index 0000000..559f24b
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/InterfaceType.java
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.Map;
+
+import com.google.common.collect.Maps;
+
+/**
+ * Interface type definition, spec section 3.6.5
+ */
+public interface InterfaceType extends TOSCAObject<InterfaceType> {
+
+	public String name();
+
+	public String derived_from();
+	
+	public String description();
+	
+	public String version();
+	
+	public default Metadata metadata() {
+		return (Metadata)proxy("metadata", Metadata.class);
+	}
+
+	public default Properties inputs() {
+		return (Properties)proxy("inputs", Properties.class);
+	}
+
+	/**
+   * The set of operations, made up by all keys but the ones above ..
+   */
+	public default Operations operations() {
+		return (Operations)
+			TOSCAProxy.record(info(),
+												info ->	TOSCAProxy.buildMap(null,
+																										Maps.filterKeys((Map)info,
+													 																					key -> !("derived_from".equals(key) ||
+																											  						 				 "description".equals(key) ||
+																																						 "version".equals(key) ||
+																																						 "metadata".equals(key) ||
+																																						 "inputs".equals(key))),
+															 											Operations.class));
+	
+	}
+	
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/InterfaceTypes.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/InterfaceTypes.java
new file mode 100644
index 0000000..4b42c8e
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/InterfaceTypes.java
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface InterfaceTypes extends TOSCAMap<InterfaceType> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Metadata.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Metadata.java
new file mode 100644
index 0000000..8e395dc
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Metadata.java
@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+/*
+ * No predefined entries here, so just use the java.util.Map interface get, i.e. get("some_entry_name")
+ */
+public interface Metadata extends TOSCAObject<Metadata> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Models.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Models.java
new file mode 100644
index 0000000..868d059
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Models.java
@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.io.File;
+import java.util.Map;
+
+import org.onap.tosca.checker.Target;
+import org.onap.tosca.checker.Catalog;
+import org.onap.tosca.checker.Checker;
+
+
+public class Models {
+
+	public static ServiceTemplate service_template(Target theTarget) {
+		return TOSCAProxy.buildObject("", (Map)theTarget.getTarget(), ServiceTemplate.class);
+	}
+
+
+
+  public static void main(String[] theArgs) {
+
+		try {
+			Catalog cat = new Checker().check(new File(theArgs[0]));
+
+			for (Target t: cat.targets()) {
+				System.err.println(t.getLocation() + "\n" + cat.importString(t) + "\n" + t.getReport());
+			}
+
+			//for (Target t: cat.sortedTargets()) {
+			//	System.out.println(t);
+			//}
+
+			ServiceTemplate tmpl = service_template(cat.topTargets().iterator().next());
+
+			NodeTypes node_types = tmpl.node_types();
+			if (node_types != null) {
+				for (NodeType nt: node_types.values()) {
+					System.out.println(" ** node type : " + nt.name());
+					Requirements reqs = nt.requirements();
+					if (reqs != null) {
+						for (Requirement req: reqs)
+							System.out.println("\t ** requirement " + req.name() + "/" + req.capability());
+					}
+				}
+			}
+
+			Substitution subs = tmpl.topology_template().substitution_mappings();
+			System.out.format("Substitution Mapping %s", subs.node_type());
+			Substitution.Mappings maps = subs.capabilities();
+			if (maps != null) {
+				for (Substitution.Mapping m: maps.values())
+					System.out.format("\n\tCapability mapping %s : %s)", m.target(), m.mapping());
+			} 
+			maps = subs.requirements();
+			if (maps != null) {
+				for (Substitution.Mapping m: maps.values())
+					System.out.format("\n\tRequirement mapping %s : %s", m.target(), m.mapping());
+			} 
+/*
+for(NodeTemplate nt: tmpl.topology_template().node_templates().values()) {
+	System.out.println(" ** node : " + nt.name() + " : " + nt.type());
+	PropertiesAssignments props = nt.properties();
+	if (props != null) {
+		props.entrySet().stream().forEach(e -> {
+			System.out.println(" ** property : " + e.getKey() + " : " + e.getValue());
+																						});
+	}
+*/
+		}
+		catch (Exception x) {
+			x.printStackTrace();
+		}
+	}
+}
+
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/NodeFilter.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/NodeFilter.java
new file mode 100644
index 0000000..27e3de2
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/NodeFilter.java
@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+/**
+ * Node filter definition, spec section 
+ */
+public interface NodeFilter extends TOSCAObject<NodeFilter> {
+
+	public default Properties properties() {
+		return (Properties)proxy("properties", Properties.class);
+	}
+
+	public default Capabilities capabilities() {
+		return (Capabilities)proxy("capabilities", Capabilities.class);
+	}
+	
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/NodeTemplate.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/NodeTemplate.java
new file mode 100644
index 0000000..6f20e2b
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/NodeTemplate.java
@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.List;
+
+/**
+ * See tosca spec section 
+ */
+public interface NodeTemplate extends TOSCAObject<NodeTemplate> {
+
+	public String name();
+
+	public String type();
+	
+	public String description();
+	
+	public List<String> directives();
+	
+	public String copy();
+
+	public default Metadata metadata() {
+		return (Metadata)proxy("metadata", Metadata.class);
+	}
+
+	public default PropertiesAssignments properties() {
+		return (PropertiesAssignments)proxy("properties", PropertiesAssignments.class);
+	}
+	
+	public default AttributesAssignments attributes() {
+		return (AttributesAssignments)proxy("attributes", AttributesAssignments.class);
+	}
+	
+	public default CapabilitiesAssignments capabilities() {
+		return (CapabilitiesAssignments)proxy("capabilities", CapabilitiesAssignments.class);
+	}
+	
+	public default RequirementsAssignments requirements() {
+		return (RequirementsAssignments)proxy("requirements", RequirementsAssignments.class);
+	}
+
+	public default TemplateInterfaces interfaces() {
+		return (TemplateInterfaces)proxy("interfaces", TemplateInterfaces.class);
+	}
+
+	public default Artifacts artifacts() {
+		return (Artifacts)proxy("artifacts", Artifacts.class);
+	}
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/NodeTemplates.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/NodeTemplates.java
new file mode 100644
index 0000000..4e4bb09
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/NodeTemplates.java
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface NodeTemplates extends TOSCAMap<NodeTemplate> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/NodeType.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/NodeType.java
new file mode 100644
index 0000000..06d79bb
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/NodeType.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+/**
+ * Node type definition, spec section 3.6.9
+ */
+public interface NodeType extends TOSCAObject<NodeType> {
+
+	public String name();
+
+	public String derived_from();
+	
+	public String description();
+	
+	public String version();
+	
+	public default Metadata metadata() {
+		return (Metadata)proxy("metadata", Metadata.class);
+	}
+
+	public default Properties properties() {
+		return (Properties)proxy("properties", Properties.class);
+	}
+
+	public default Attributes attributes() {
+		return (Attributes)proxy("attributes", Attributes.class);
+	}
+
+	public default Requirements requirements() {
+		return (Requirements)proxy("requirements", Requirements.class);
+	}
+
+	public default Capabilities capabilities() {
+		return (Capabilities)proxy("capabilities", Capabilities.class);
+	}
+
+	public default TypeInterfaces interfaces() {
+		return (TypeInterfaces)proxy("interfaces", TypeInterfaces.class);
+	}
+
+	public default Artifacts artifacts() {
+		return (Artifacts)proxy("artifacts", Artifacts.class);
+	}
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/NodeTypes.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/NodeTypes.java
new file mode 100644
index 0000000..e61deb4
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/NodeTypes.java
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface NodeTypes extends TOSCAMap<NodeType> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Operation.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Operation.java
new file mode 100644
index 0000000..fbc66b3
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Operation.java
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+/**
+ * This is the type specific defintion, as per spec section 3.5.13.2.2
+ */
+public interface Operation extends TOSCAObject<Operation> {
+
+
+		public String name();
+		
+		public String description();
+	
+		public String implementation();
+
+		public default Properties inputs() {
+			return (Properties)proxy("inputs", Properties.class);
+		}
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Operations.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Operations.java
new file mode 100644
index 0000000..726ad90
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Operations.java
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface Operations extends TOSCAMap<Operation> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Outputs.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Outputs.java
new file mode 100644
index 0000000..2daed56
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Outputs.java
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface Outputs extends TOSCAMap<Parameter> {
+
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Parameter.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Parameter.java
new file mode 100644
index 0000000..e1d771b
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Parameter.java
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+/**
+ * Spec section 3.5.12
+ */
+public interface Parameter extends TOSCAObject<Parameter> {
+
+	public String name();
+
+	public String type();
+
+	public String description();
+	
+	public Object value();
+
+	public default Object _default() {
+		return info().get("default");
+	}
+
+	public boolean required();
+
+	public Status status();
+
+	public default Constraints constraints() {
+		return (Constraints)proxy("constraints", Constraints.class);
+	}
+
+	public default EntrySchema entry_schema() {
+		return (EntrySchema)proxy("entry_schema", EntrySchema.class);
+	}
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Policies.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Policies.java
new file mode 100644
index 0000000..21a6be5
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Policies.java
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface Policies extends TOSCAMap<Policy> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Policy.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Policy.java
new file mode 100644
index 0000000..4d291a9
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Policy.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.List;
+
+/**
+ * Policy type definition, spec section 3.7.6
+ */
+public interface Policy extends TOSCAObject<Policy> {
+
+	public String type();
+	
+	public String description();
+	
+	public String version();
+	
+	public default Metadata metadata() {
+		return (Metadata)proxy("metadata", Metadata.class);
+	}
+	
+	public List<String> targets();
+
+	public default PropertiesAssignments properties() {
+		return (PropertiesAssignments)proxy("properties", PropertiesAssignments.class);
+	}
+
+	public default PolicyType.Triggers triggers() {
+		return (PolicyType.Triggers)proxy("triggers", PolicyType.Triggers.class);
+	}
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/PolicyType.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/PolicyType.java
new file mode 100644
index 0000000..08a4bfa
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/PolicyType.java
@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.List;
+
+/**
+ * Policy type definition, spec section 3.6.12
+ */
+public interface PolicyType extends TOSCAObject<PolicyType> {
+
+	public String name();
+
+	public String derived_from();
+	
+	public String description();
+	
+	public String version();
+	
+	public default Metadata metadata() {
+		return (Metadata)proxy("metadata", Metadata.class);
+	}
+	
+	public List<String> targets();
+
+	public default Properties properties() {
+		return (Properties)proxy("properties", Properties.class);
+	}
+
+	public default Triggers triggers() {
+		return (Triggers)proxy("triggers", Triggers.class);
+	}
+
+	public interface Triggers extends TOSCAMap<Trigger> {
+
+	}
+
+	public interface Trigger extends TOSCAObject<Trigger> {
+
+		public String description();
+		
+		public String event_type();
+		
+		public String schedule();
+	
+		public default Constraints constraint() {
+			return (Constraints)proxy("constraint", Constraints.class);
+		}
+
+		public default Constraints condition() {
+			return (Constraints)proxy("condition", Constraints.class);
+		}
+
+		public int period();
+		
+		public int evaluations();
+
+		public String method();
+		
+		public String action();
+
+		//target_filter	
+		public default EventFilter target_filter() {
+			return (EventFilter)proxy("target_filter", EventFilter.class);
+		}
+
+	}
+	
+	public interface EventFilter extends TOSCAObject<EventFilter> {
+
+		public String node();
+
+		public String requirement();
+
+		public String capability();
+
+	}
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/PolicyTypes.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/PolicyTypes.java
new file mode 100644
index 0000000..8ef6278
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/PolicyTypes.java
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface PolicyTypes extends TOSCAMap<PolicyType> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Properties.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Properties.java
new file mode 100644
index 0000000..d2a8e85
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Properties.java
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface Properties extends TOSCAMap<Property> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/PropertiesAssignments.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/PropertiesAssignments.java
new file mode 100644
index 0000000..dd949ff
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/PropertiesAssignments.java
@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+/*
+ * A simple representation of the property value assignments, to be used through the Map interface
+ * Working with this more basic representation keeps all (jx)paths expressions valid 
+ */
+public interface PropertiesAssignments extends TOSCAObject<PropertiesAssignments> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Property.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Property.java
new file mode 100644
index 0000000..126a346
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Property.java
@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+/**
+ * See spec section 3.5.8
+ */
+public interface Property extends TOSCAObject<Property> {
+
+	public String name();
+
+	public String type();
+
+	public String description();
+
+	public default Object _default() {
+		return info().get("default");
+	}
+
+	public boolean required();
+
+	public Status status();
+
+	public default Constraints constraints() {
+		return (Constraints)proxy("constraints", Constraints.class);
+	}
+
+	public default EntrySchema entry_schema() {
+		return (EntrySchema)proxy("entry_schema", EntrySchema.class);
+	}
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Range.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Range.java
new file mode 100644
index 0000000..ed90ed7
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Range.java
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.List;
+
+/*
+ */
+public interface Range extends List<Object> {
+
+	public default Object lower() {
+		return get(0);
+	}
+
+	public default Object upper() {
+		return get(1);
+	}
+
+	public default boolean isUnbounded() {
+		return "UNBOUNDED".equals(upper());
+	}
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/RelationshipTemplate.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/RelationshipTemplate.java
new file mode 100644
index 0000000..89e1fa0
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/RelationshipTemplate.java
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.List;
+
+/**
+ */
+public interface RelationshipTemplate extends TOSCAObject<RelationshipTemplate> {
+
+	public String name();
+
+	public String type();
+	
+	public String description();
+	
+	public String copy();
+
+	public default Metadata metadata() {
+		return (Metadata)proxy("metadata", Metadata.class);
+	}
+
+	public default PropertiesAssignments properties() {
+		return (PropertiesAssignments)proxy("properties", PropertiesAssignments.class);
+	}
+	
+	public default AttributesAssignments attributes() {
+		return (AttributesAssignments)proxy("attributes", AttributesAssignments.class);
+	}
+	
+	public default TemplateInterfaces interfaces() {
+		return (TemplateInterfaces)proxy("interfaces", TemplateInterfaces.class);
+	}
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/RelationshipTemplates.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/RelationshipTemplates.java
new file mode 100644
index 0000000..d4f73d6
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/RelationshipTemplates.java
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface RelationshipTemplates extends TOSCAMap<RelationshipTemplate> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/RelationshipType.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/RelationshipType.java
new file mode 100644
index 0000000..844f176
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/RelationshipType.java
@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.List;
+
+/**
+ * Relationship type definition, spec section 3.6.10
+ */
+public interface RelationshipType extends TOSCAObject<RelationshipType> {
+
+	public String name();
+
+	public String derived_from();
+	
+	public String description();
+	
+	public String version();
+	
+	public default Metadata metadata() {
+		return (Metadata)proxy("metadata", Metadata.class);
+	}
+
+	public default Properties properties() {
+		return (Properties)proxy("properties", Properties.class);
+	}
+
+	public default Attributes attributes() {
+		return (Attributes)proxy("attributes", Attributes.class);
+	}
+
+	public default TypeInterfaces interfaces() {
+		return (TypeInterfaces)proxy("interfaces", TypeInterfaces.class);
+	}
+
+	public List<String> valid_target_types();
+	
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/RelationshipTypes.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/RelationshipTypes.java
new file mode 100644
index 0000000..c5144f5
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/RelationshipTypes.java
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface RelationshipTypes extends TOSCAMap<RelationshipType> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Repositories.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Repositories.java
new file mode 100644
index 0000000..b30bfe7
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Repositories.java
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface Repositories extends TOSCAMap<Repository> {
+
+}
+
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Repository.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Repository.java
new file mode 100644
index 0000000..b685378
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Repository.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.Map;
+
+
+/*
+ * Repository definition (spec section 3.6.3)
+ */
+public interface Repository extends TOSCAObject<Repository> {
+
+	/** */
+	public String name();
+
+	/** */
+	public String description();
+
+	/** */
+	public String url();
+	
+	/** */
+	public default Credential credential() {
+		return (Credential)proxy("credential", Credential.class);
+	}
+
+	/** */
+	public interface Credential extends TOSCAObject<Credential> {
+	
+		/** */
+		public String protocol();
+		
+		/** */
+		public String token_type();
+		
+		/** */
+		public String token();
+		
+		/** */
+		public String user();
+		
+		/** */
+		public Map<String,String> keys();
+	}
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Requirement.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Requirement.java
new file mode 100644
index 0000000..5e3c4f8
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Requirement.java
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+/*
+ * Requirement definition, as it appears in node type definitions (spec section 3.6.3)
+ */
+public interface Requirement extends TOSCAObject<Requirement> {
+
+	/** */
+	public String name();
+
+	/** */
+	public String capability();
+
+	/** */
+	public String node();
+
+	/** */		
+	public default Range occurences() {
+		return (Range)proxy("relationship", Range.class);
+	}
+
+	public default Relationship relationship() {
+		return (Relationship)proxy("relationship", Relationship.class);
+	}
+
+	/**
+	 * Spec section 3.6.3.2.3 
+	 */
+	public interface Relationship extends TOSCAObject<Relationship> {
+
+		public String type();
+
+		public default TypeInterfaces interfaces() {
+			return (TypeInterfaces)proxy("interfaces", TypeInterfaces.class);
+		}
+	}
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/RequirementAssignment.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/RequirementAssignment.java
new file mode 100644
index 0000000..7d03453
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/RequirementAssignment.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+/*
+ * Requirement assignment as it appears in node templates. See spec section 3.7.2
+ */
+public interface RequirementAssignment extends TOSCAObject<RequirementAssignment> {
+
+	public String name();
+
+	/**
+	 * Provide the name of either a:
+	 * 	Capability definition within a target node template that can fulfill the requirement.
+	 * 	Capability Type that the provider will use to select a type-compatible target node template to fulfill the requirement at runtime.
+	 */
+	public String capability();
+
+	/**
+	 */
+	public String node();
+	
+	/** */
+	public default NodeFilter node_filter() {
+		return (NodeFilter)proxy("node_filter", NodeFilter.class);
+	}
+
+	/** */
+	public default RelationshipAssignment relationship() {
+		return (RelationshipAssignment)proxy("relationship", RelationshipAssignment.class);
+	}
+
+	public interface RelationshipAssignment extends TOSCAObject<RelationshipAssignment> {
+
+		public String type();
+
+		public default PropertiesAssignments properties() {
+			return (PropertiesAssignments)proxy("properties", PropertiesAssignments.class);
+		}
+
+		public default TemplateInterfaces interfaces() {
+			return (TemplateInterfaces)proxy("interfaces", TemplateInterfaces.class);
+		}
+	}
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Requirements.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Requirements.java
new file mode 100644
index 0000000..b29a256
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Requirements.java
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface Requirements extends TOSCASeq<Requirement> {
+
+}
+
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/RequirementsAssignments.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/RequirementsAssignments.java
new file mode 100644
index 0000000..a621c44
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/RequirementsAssignments.java
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface RequirementsAssignments extends TOSCASeq<RequirementAssignment> {
+
+}
+
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/ServiceTemplate.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/ServiceTemplate.java
new file mode 100644
index 0000000..7eb686c
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/ServiceTemplate.java
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+/**
+ */
+public interface ServiceTemplate extends TOSCAObject<ServiceTemplate> {
+
+	public String tosca_definitions_version();
+
+	public String description();
+
+	public default Metadata metadata() {
+		return (Metadata)proxy("metadata", Metadata.class);
+	}
+	
+	public default Imports imports() {
+		return (Imports)proxy("imports", Imports.class);
+	}
+	
+	public default Repositories repositories() {
+		return (Repositories)proxy("repositories", Repositories.class);
+	}
+	
+	public default ArtifactTypes artifact_types() {
+		return (ArtifactTypes)proxy("artifact_types", ArtifactTypes.class);
+	}
+	
+	public default DataTypes data_types() {
+		return (DataTypes)proxy("data_types", DataTypes.class);
+	}
+	
+	public default NodeTypes node_types() {
+		return (NodeTypes)proxy("node_types", NodeTypes.class);
+	}
+	
+	public default GroupTypes group_types() {
+		return (GroupTypes)proxy("group_types", GroupTypes.class);
+	}
+	
+	public default PolicyTypes policy_types() {
+		return (PolicyTypes)proxy("policy_types", PolicyTypes.class);
+	}
+	
+	public default RelationshipTypes relationship_types() {
+		return (RelationshipTypes)proxy("relationship_types", RelationshipTypes.class);
+	}
+	
+	public default CapabilityTypes capability_types() {
+		return (CapabilityTypes)proxy("capability_types", CapabilityTypes.class);
+	}
+	
+	public default InterfaceTypes interface_types() {
+		return (InterfaceTypes)proxy("interface_types", InterfaceTypes.class);
+	}
+
+	public default TopologyTemplate topology_template() {
+		return (TopologyTemplate)proxy("topology_template", TopologyTemplate.class);
+	}
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Status.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Status.java
new file mode 100644
index 0000000..e76bff5
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Status.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public enum Status {
+
+	supported,
+	unsupported,
+	experimental,
+	deprecated
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Substitution.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Substitution.java
new file mode 100644
index 0000000..c41a429
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/Substitution.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.List;
+
+
+/**
+ * Spec section 3.8
+ */
+public interface Substitution extends TOSCAObject<Substitution> {
+
+	public String node_type();
+
+	public default Mappings capabilities() {
+		return (Mappings)proxy("capabilities", Mappings.class);
+	}
+
+	public default Mappings requirements() {
+		return (Mappings)proxy("requirements", Mappings.class);
+	}
+
+	/** */
+	public interface Mappings extends TOSCAMap<Mapping> {
+	}
+
+	/** */
+	public interface Mapping extends TOSCAObject<Mapping> {
+
+		/** to promote the key */
+		public String name();
+
+		/**
+		 */
+		public default String target() {
+			return name();
+		}
+
+		/** */
+		public default List<String> mapping() {
+			return (List<String>)info().values().iterator().next();			
+		}
+	}
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TOSCAMap.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TOSCAMap.java
new file mode 100644
index 0000000..50feb44
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TOSCAMap.java
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.Map;
+
+
+/*
+ * used to render TOSCA constructs that are maps of names to actual construct data:
+ *  - node types, etc
+ *  - topology template inputs, etc
+ */
+public interface TOSCAMap<T extends TOSCAObject<T>> extends Map<String, T> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TOSCAObject.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TOSCAObject.java
new file mode 100644
index 0000000..a0332fd
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TOSCAObject.java
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.Map;
+import java.util.List;
+import java.util.Collections;
+
+import java.lang.reflect.Proxy;
+
+/*
+ * Some choice to make here: do we explcitly extend Map or not
+ * Note that this makes assumptions about the POJO representation of the yaml document.
+ */
+public interface TOSCAObject<T extends TOSCAObject<T>> extends Map<String, Object> {
+
+	/** */
+	public abstract Map info();
+
+	/* if the key is absent this produces a null value, rather normal I'd say
+	 */
+	public default <A> A proxy(String theKey, final Class<A> theType) {
+		return (A)/*info().*/computeIfPresent(theKey,
+																			 (key, val)-> {
+																					/*
+																					if (val instanceof TOSCAObject ||
+																							val instanceof TOSCAMap ||
+																							val instanceof TOSCASeq)
+																						return val;
+																					*/
+																					//this makes the assumption that no other proxies are at play
+																					if (Proxy.isProxyClass(val.getClass()))
+																						return val;
+
+																					if (val instanceof Map && TOSCAMap.class.isAssignableFrom(theType))
+																						return TOSCAProxy.buildMap((String)key, (Map<String,Map>)val, (Class<TOSCAMap>)theType);
+																					if (val instanceof List && TOSCASeq.class.isAssignableFrom(theType))
+																						return TOSCAProxy.buildSeq((List)val, (Class<TOSCASeq>)theType);
+																					
+																					return TOSCAProxy.buildObject((String)key, (Map<String,Map>)val, theType);
+																				});
+	}
+
+	public default <A extends List> A proxyList(String theKey, final Class<A> theType) {
+		return (A)computeIfPresent(theKey,
+															 (key, val)-> {
+																					if (Proxy.isProxyClass(val.getClass()))
+																						return val;
+																					return TOSCAProxy.buildList((List)val, theType);
+																				});
+	}
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TOSCAProxy.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TOSCAProxy.java
new file mode 100644
index 0000000..bce8675
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TOSCAProxy.java
@@ -0,0 +1,179 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.List;
+import java.util.LinkedList;
+import java.util.Map;
+import java.util.HashMap;
+import java.util.Collections;
+
+import java.util.stream.Collectors;
+
+import java.util.function.Function;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import java.lang.reflect.Type;
+import java.lang.reflect.Method;
+import java.lang.reflect.Array;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.InvocationTargetException;
+
+import java.lang.invoke.MethodHandles;
+
+import com.google.common.reflect.Invokable;
+import com.google.common.reflect.AbstractInvocationHandler;
+
+
+/**
+ */
+public class TOSCAProxy 
+									extends AbstractInvocationHandler {
+
+
+	public static Constructor<MethodHandles.Lookup> lookupHandleConstructor;
+
+	static {
+		try {
+			lookupHandleConstructor =
+					MethodHandles.Lookup.class.getDeclaredConstructor(Class.class,
+																														int.class);
+
+			if (!lookupHandleConstructor.isAccessible()) {
+   			lookupHandleConstructor.setAccessible(true);
+			}
+		}
+		catch (Exception x) {
+			throw new RuntimeException(x);
+		}	
+	}
+
+	protected static <T> Class<T> typeArgument(Class theType) {
+		return (Class<T>)	
+						((ParameterizedType)theType.getGenericInterfaces()[0]).
+							getActualTypeArguments()[0];
+	}
+
+	private static Map	proxyRecords = new HashMap();
+
+	/** */
+	public static Object record(Object theRef, Function theProxyBuilder) {
+		return proxyRecords.computeIfAbsent(theRef, theProxyBuilder);
+	}
+
+	/* a version allowing for the 'decoration/wrapping' of a basic list
+	 */
+	public static <T extends List> T buildList(final List theInfo, Class<T> theType) {
+		return (T)java.lang.reflect.Proxy.newProxyInstance(
+							TOSCAProxy.class.getClassLoader(),
+							new Class[] { theType },
+							new AbstractInvocationHandler() {
+								protected Object handleInvocation(Object theProxy,Method theMethod,Object[] theArgs)
+																																												throws Throwable {
+									return theMethod.invoke(theInfo, theArgs);
+								}
+							});
+	}
+	
+	/*
+ 	 * This is targeted at lists of one entry maps seen in in the TOSCA spec 
+   */
+	public static <T extends TOSCASeq> T buildSeq(final List<Map> theInfo, Class<T> theType) {
+		theInfo.replaceAll((value) -> { Map.Entry<String,Map> entry = (Map.Entry<String,Map>)
+																																			value.entrySet().iterator().next();
+																		return buildObject(entry.getKey(), entry.getValue(), typeArgument(theType)); 
+																	});
+		return (T)java.lang.reflect.Proxy.newProxyInstance(
+							TOSCAProxy.class.getClassLoader(),
+							new Class[] { theType },
+							new AbstractInvocationHandler() {
+								protected Object handleInvocation(Object theProxy,Method theMethod,Object[] theArgs)
+																																												throws Throwable {
+									//A Seq is nothing but a List so just propagate the call ..
+									return theMethod.invoke(theInfo, theArgs);
+								}
+							});
+	}
+	
+	/*
+ 	 * All entries in the map will become TOSCAObject instances (used for collections of constructs)
+   */
+	public static <T extends TOSCAMap> T buildMap(String theName, Map<String, ?> theInfo, Class<T> theType) {
+		theInfo.replaceAll((name, value) -> {
+													return
+														value instanceof Map ?
+															buildObject(name, (Map)value, typeArgument(theType)) :
+															buildObject(name, Collections.singletonMap("value", value), typeArgument(theType));
+													});
+		return buildObject(theName, theInfo, theType);
+	}
+
+	public static <T> T buildObject(String theName, Map theInfo, Class<T> theType) {
+		return (T)java.lang.reflect.Proxy.newProxyInstance(
+							TOSCAProxy.class.getClassLoader(),
+							new Class[] { theType /*, Map.class*/ },
+							new TOSCAProxy(theName, theInfo));
+	}
+/*
+	public static <T> T build(String theName, Map theInfo, Class<T> theType) {
+		if (TOSCAMap.class.isAssignableFrom(theType))
+			return buildMap(theName, theInfo, (Class<TOSCAMap>)theType);
+		else
+			return buildObject(theName, theInfo, theType);
+	}
+*/
+	private String name;
+	private Map 	 info;
+
+	protected TOSCAProxy(String theName, Map theInfo) {
+		this.name = theName;
+		this.info = theInfo;
+	}
+
+	protected Object handleInvocation(
+											Object theProxy,Method theMethod,Object[] theArgs)
+																												throws Throwable {
+
+//System.out.println(" ** proxy looking for " + theMethod + " in " + name + "&" + info);
+
+		//if the method was declared in Map.class, just default to 'info' (we should make this read only)
+		if (Map.class.equals(theMethod.getDeclaringClass())) {
+			return theMethod.invoke(this.info, theArgs);
+		}
+
+		if (theMethod.isDefault()) {
+			final Class<?> declaringClass = theMethod.getDeclaringClass();
+			return lookupHandleConstructor
+							.newInstance(declaringClass, MethodHandles.Lookup.PRIVATE)
+							.unreflectSpecial(theMethod, declaringClass)
+							.bindTo(theProxy)
+							.invokeWithArguments(theArgs);
+		}
+
+		if ("info".equals(theMethod.getName())) {
+			return this.info;
+		}
+
+		if ("name".equals(theMethod.getName())) {
+			return this.name;
+		}
+
+		return this.info.get(theMethod.getName());
+	}
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TOSCASeq.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TOSCASeq.java
new file mode 100644
index 0000000..e335e5a
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TOSCASeq.java
@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.List;
+
+
+/*
+ * used to render TOSCA constructs that are list of actual constructs:
+ *  - requirements
+ */
+public interface TOSCASeq<T extends TOSCAObject<T>> extends List<T> {
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TemplateInterface.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TemplateInterface.java
new file mode 100644
index 0000000..628e2f7
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TemplateInterface.java
@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.List;
+import java.util.Map;
+
+import com.google.common.collect.Maps;
+
+
+/*
+ * Interface definition used in templates (node, relationship)
+ */
+public interface TemplateInterface extends TOSCAObject<TemplateInterface> {
+
+	public String name();
+
+	public default Inputs inputs() {
+		return (Inputs)proxy("inputs", Inputs.class);
+	}
+
+	/**
+	 * See InterfaceType for the reason for the implementation below. 
+	 * Use the template specific operation definition, as per spec section 3.5.13.2.3
+	 */
+	public default TemplateInterface.Operations operations() {
+		return (Operations)
+			TOSCAProxy.record(info(),
+												info ->	TOSCAProxy.buildMap(null,
+																										Maps.filterKeys((Map)info,
+													 																					key -> !("inputs".equals(key))),
+															 											Operations.class));
+	}
+
+	/**
+	 * Is this to be viewed as an 'operation assignment' ??
+	 */	
+	public interface Operations extends TOSCAMap<Operation> {
+	}
+
+	/*
+	 * Template specific operation definition, section 3.5.13.2.3
+	 */
+	public interface Operation extends TOSCAObject<Operation> {
+
+		public String name();
+		
+		public String description();
+	
+		public default PropertiesAssignments inputs() {
+			return (PropertiesAssignments)proxy("inputs", PropertiesAssignments.class);
+		}
+		
+		public default Implementation implementation() {
+			return (Implementation)proxy("implementation", Implementation.class);
+		}
+
+		/**
+		 */
+		public interface Implementation extends TOSCAObject<Implementation> {
+		
+			public String primary();
+			
+			public List<String> dependencies();
+	
+		}
+			
+	}
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TemplateInterfaces.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TemplateInterfaces.java
new file mode 100644
index 0000000..b4b40a2
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TemplateInterfaces.java
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface TemplateInterfaces extends TOSCAMap<TemplateInterface> {
+
+}
+
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TopologyTemplate.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TopologyTemplate.java
new file mode 100644
index 0000000..88328ba
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TopologyTemplate.java
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface TopologyTemplate extends TOSCAObject<TopologyTemplate> {
+
+	public String description();
+
+	public default Inputs inputs() {
+		return (Inputs)proxy("inputs", Inputs.class);
+	}
+	
+	public default Outputs outputs() {
+		return (Outputs)proxy("Outputs", Outputs.class);
+	}
+
+	public default NodeTemplates node_templates() {
+		return (NodeTemplates)proxy("node_templates", NodeTemplates.class);
+	}
+	
+	public default RelationshipTemplates relationship_templates() {
+		return (RelationshipTemplates)proxy("relationship_templates", RelationshipTemplates.class);
+	}
+
+	public default Groups groups() {
+		return (Groups)proxy("groups", Groups.class);
+	}
+
+	public default Substitution substitution_mappings() {
+		return (Substitution)proxy("substitution_mappings", Substitution.class);
+	}
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TypeInterface.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TypeInterface.java
new file mode 100644
index 0000000..77836f6
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TypeInterface.java
@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+import java.util.Map;
+
+import com.google.common.collect.Maps;
+
+/*
+ * Interface definition used in types (node, relationship)
+ */
+public interface TypeInterface extends TOSCAObject<TypeInterface> {
+
+	public String name();
+	
+	public String type();
+
+	public default Inputs inputs() {
+		return (Inputs)proxy("inputs", Inputs.class);
+	}
+
+	public default Operations operations() {
+		//not as obvious because we need to pick up all the keys EXCEPT "inputs" and "type";
+		//as a result we cannot pick a key to attach the proxy to (and end up in the best case creating one every time ..).
+		//I wish I had a more elegant solution but in order to avoid building a new proxy every time we get here
+		//we register the long-lasting reference to proxy association ..
+
+		return (Operations)
+			TOSCAProxy.record(info(),
+												info ->	TOSCAProxy.buildMap(null,
+																										Maps.filterKeys((Map)info,
+													 																					key -> !("type".equals(key) ||
+																											  						 				 "inputs".equals(key))),
+															 											Operations.class));
+	}
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TypeInterfaces.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TypeInterfaces.java
new file mode 100644
index 0000000..fb271d7
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/TypeInterfaces.java
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.model;
+
+
+public interface TypeInterfaces extends TOSCAMap<TypeInterface> {
+
+}
+
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/package-info.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/package-info.java
new file mode 100644
index 0000000..783389e
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/model/package-info.java
@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+
+/**
+ * The package contains Java representations of TOSCA constructs.
+ * During processing (parsing, checking, cataloging) a POJO representation of the TOSCA yaml document content
+ * is being used. For any post-processing the user has the option of wrapping the POJO representations in these
+ * domain specific representations.
+ * Domain specific elements are created 'as needed' as the client navigates through the template content and the
+ * goal here was not to change the POJO-based structure, but just to wrap it in compatible elements (in this way
+ * all other methods of post processing stay compatible: jxpath, etc).
+ * The TOSCA specific representations are defined as interfaces for which implementations are built at run-time,
+ * implementations which delegate to the existing POJO representations resulting from the checker.
+ * 
+ * The entry points are defined in {@link org.onap.tosca.checker.models.Models Models}.
+ * 
+ * ToDo: more entry points needed, at least for catalog based navigation of available types.
+ */
+
+package org.onap.tosca.checker.model;
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/package-info.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/package-info.java
new file mode 100644
index 0000000..818eeab
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/package-info.java
@@ -0,0 +1,142 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+
+/**
+ * The checker provides an api/tool for the verification of TOSCA yaml files.
+ * <p>
+ * It provides a three stage processing of a tosca yaml file:
+ *   - yaml verification: is the document a valid yaml document as per yaml.org/spec. In particular we're using 
+ *   the snakeyaml library for parsing the yaml document to a nested structure of java objects. Multiple yaml
+ *	 documents per storage element/yaml character stream (file, stream) are supported, see section 9 of yaml spec. 
+ *   - tosca yaml grammar validation: is the document a valid tosca yaml
+ *   document, as per the the TOSCA simple profile for yaml. We use a modified
+ *   version of the kwalify library for this task. The grammar for TOSCA yaml
+ *   is itself a yaml document (found in the package in 
+ *   resources/tosca-schema.yaml). There are certain limitations on how far 
+ *   this grammar can go.  
+ *   - consistency verification: we check the type hierarchies for all TOSCA
+ *   constructs (data types, capability types, node types, etc), the definition
+ *   of all facets of a construct (properties, attributes, etc) across the type
+ *   hierachies, the conformity of construct templates (node templates, ..) with
+ *   their types, data valuations(input assignements, constants, function calls).
+ *
+ * Each stage is blocking, i.e. a stage will be performed only if the previous
+ * one completed successfully. Additional procesing can be added to each stage by 
+ * providing code annotated as per the {@link org.onap.tosca.checker.annotations Annotations} package.  
+ * <p>
+ * The verification is done across all the imported documents. The common TOSCA 
+ * types are by default made available to all documents being processed (the
+ * specification is in resources/tosca-common-types.yaml). Networking related
+ * types can be made available by importing resources/tosca-network-types.yaml
+ * while the tosca nfv profile definitions are available at
+ * resources/tosca-nfv-types.yaml. 
+ * <p>
+ * The main java classes exposed by the package are the Checker, Target
+ * and Report. A Target represents a document processed by the Checker. While
+ * the Checker starts with a top Target, through import statements it can end up
+ * processing a number of Targets. The results of processing a Target are made
+ * available through a Report which currently is nothing more that a list of
+ * recorded errors.
+ *
+ * <div>
+ * {@code
+ *   Checker checker = new Checker();
+ *	 checker.check("tests/example.yaml");
+ *
+ *	 for (Target t: checker.targets())
+ *     System.out.println(t.getLocation() + "\n" + t.getReport());
+ * }
+ * </div>
+ * <p>
+ * A {@link org.onap.tosca.checker.Report report} consolidates the problems encountered
+ * in the processed documents per Target.
+ * The errors are recorded as instances of Exception, mostly due to the fact
+ * snakeyaml and kwalify do report errors as exceptions. As such there are 3
+ * basic types of errros to be expected in a report: YAMLException (from
+ * snakeyaml, related to parsing), ValidationException (from kwalify, tosca
+ * grammar validation), TargetException (from the checker itself). This might
+ * change as we're looking to unify the way errors are reported. A Report 
+ * object has a user friendly toString function.
+ *
+ * A CheckerException thrown during the checking process is an indication of a
+ * malfunction in the checker itself.
+ * <p>
+ * The checker handles targets as URIs. The resolution of a target consists in
+ * going from a string representing some path/uri to the absolute URI. 
+ * The Targets are found through a TargetLocator which interprets a location string
+ * as an URI. A custom TargetLocator (capable of interpreting particular URI schemes)
+ * can be plugged in the Checker. Locating a target is actually the first stage of
+ * target processing and and intrisic part of the process (resolving imported targets). 
+ * The package provides a default {@link org.onap.tosca.checker.CommonLocator locator} 
+ * which handles the common uri schemes (the jdk recognizes).
+ * The example above highlights the fact that even when processing starts with one target
+ * it could end up going over a larger set, through imports. 
+ *
+ * The results of processing a TOSCA yaml document (all all related documents through 
+ * the import relationship) are stored in a {@link org.onap.tosca.checker.Catalog catalog}.
+ * Catalogs are re-usable and the checker provides methods for processing targets with
+ * respect to an existing catalog. 'With respect to a catalog' means that all the types
+ * available in that catalog are visisble to the targets being processed; this facilitates
+ * the processing of TOSCA templates organized as a schema (types specifications) and 
+ * topology templates.
+ * <p>
+ * The most common entry point is {@link org.onap.tosca.checker.Checker#check(String) check},
+ * where the argument is passed to thelocator and once a {@link org.onap.tosca.checker.Target target}
+ * has been obtained, processing continues with the other stages.
+ * The checker has processing entry points past the first two processing stages: an already located
+ * target <br/>
+ *	<ul>
+ *    <li>{@link org.onap.tosca.checker.Checker#check(Target) check}</li>
+ *    <li>{@link org.onap.tosca.checker.Checker#check(Target, Catalog) check}</li>
+ *  </ul>
+ * and after a target located and parsed <br/>
+ *	<ul>
+ *    <li>{@link org.onap.tosca.checker.Checker#validate(Target) check}</li>
+ *    <li>{@link org.onap.tosca.checker.Checker#validate(Target, Catalog) check}</li>
+ *  </ul>
+ * </p>
+ * <p>
+ * The build process provides an all-in-one jar to facilitate the usage as a tool:
+ * <p>
+ * Other:
+ * <ul>
+ *   <li>the checker performs during tosca grammar validation a 'normalization'
+ *   process as the tosca yaml profile allows for short forms in the 
+ *   specification of a number of its constructs (see spec). The checker changes
+ *   the actual structure of the parsed document such that only normalized
+ *   (complete) forms of specification are present before the checking phase.
+ *   (the kwalify library was extended in order to be able to specify these
+ *   short forms in the grammar itself and process/tolerate them at validation
+ *   time).
+ *   </li>
+ *   <li>the checker contains an internal catalog where the types and templates
+ *   of different constructs are aggregated and indexed across all targets in
+ *   order to facilitate the checking phase. Catalogs can be 'linked' and the
+ *   resolution process delegated (the checker maintains a basic catalog with
+ *   the core and common types and there is always a second catalog maintaining
+ *   the information related to the current targets).
+ *   The catalog is currently not exposed by the library.
+ *   </li>
+ *   <li>imports processing: the import statements present in a target are first 
+ *   'detected' during tosca yaml grammar validation phase. At that stage all
+ *   imports are (recursively) parsed and validated (first 2 phases). Checking
+ *   off all imports (recursively) is done during stage 3.
+ *   </li>
+ * <ul>
+ * <p>
+ * ToDo:
+ * 	 - nobody says the parsing cannot be pluggable: snakeyaml could be replaced by
+ * anything that can take a Reader and produce a POJO hierarchy for the next stages. 
+ */
+
+package org.onap.tosca.checker;
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/JSP.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/JSP.java
new file mode 100644
index 0000000..4183c75
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/JSP.java
@@ -0,0 +1,659 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.processing;
+
+import java.io.FileReader;
+import java.io.IOException;
+import java.io.File;
+
+import java.net.URI;
+
+import java.util.Set;
+import java.util.Map;
+import java.util.List;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.stream.Collectors;
+import java.util.function.Consumer;
+import java.util.function.BiFunction;
+import java.util.function.Predicate;
+
+import javax.script.Invocable;
+import javax.script.Compilable;
+import javax.script.CompiledScript;
+import javax.script.Bindings;
+import javax.script.SimpleBindings;
+import javax.script.ScriptContext;
+import javax.script.SimpleScriptContext;
+import javax.script.ScriptEngine;
+import javax.script.ScriptEngineManager;
+import javax.script.ScriptException;
+
+import jdk.nashorn.api.scripting.JSObject;
+import jdk.nashorn.api.scripting.AbstractJSObject;
+
+import org.apache.commons.jxpath.JXPathContext;
+import org.apache.commons.jxpath.JXPathException;
+
+import org.onap.tosca.checker.Target;
+import org.onap.tosca.checker.Catalog;
+import org.onap.tosca.checker.Report;
+import org.onap.tosca.checker.Construct;
+import org.onap.tosca.checker.Facet;
+
+
+/**
+ * Java Script Processor
+ * Each script is represented by a Target and the JSP processor maintains a collection of Targets, i.e. scripts.
+ * A collection of targets can be used with only one JSP processor at a time (as the processor stores processor specific * compiled versions within the target). 
+ */
+public class JSP implements Processor<JSP> {
+
+  private ScriptEngine engine;
+	private Collection<? extends Target> targets;
+
+  public JSP(String[] theScripts) {
+		this(Arrays.stream(theScripts)
+								.map(s -> new Target(s, new File(s).toURI()))
+								.collect(Collectors.toList()));
+	}
+  
+	public JSP(File[] theScripts) {
+		this(Arrays.stream(theScripts)
+								.map(s -> new Target(s.getName(), s.toURI()))
+								.collect(Collectors.toList()));
+	}
+	
+	public JSP(URI[] theScripts) {
+		this(Arrays.stream(theScripts)
+								.map(s -> new Target(s.toString(), s))
+								.collect(Collectors.toList()));
+	}
+
+	/**
+   * The given collection is allowed to change while used by the JSP engine but access to it needs to be synchronized.
+   * The engine uses the target field of each Target to store a compiled version of each script. An external reset of
+   * this field (maybe in order to indicate some change in the Target) will caue a re-compilation of the Target.
+   */
+	public JSP(Collection<? extends Target> theTargets) {
+		this.targets = theTargets;
+    ScriptEngineManager engineManager = new ScriptEngineManager();
+    this.engine = engineManager.getEngineByName("nashorn");
+	}
+
+	public Collection<? extends Target> targets() {
+		return this.targets;
+	}
+
+	/* pre-compiles all known targets
+   */
+	protected void compile() throws ProcessorException {
+		synchronized (this.targets) {
+			for (Target t: this.targets)
+				compile(t);
+		}
+	}
+
+	protected CompiledScript compile(Target theTarget) throws ProcessorException {
+
+		CompiledScript cs = null;
+
+		synchronized(theTarget) {		
+			try {
+				cs = (CompiledScript)theTarget.getTarget();
+			}
+			catch(ClassCastException ccx) {
+				throw new ProcessorException(theTarget, "Unexpected target content");
+			}
+
+			if (cs == null) {
+				try {
+					cs = ((Compilable)this.engine).compile(theTarget.open());
+					theTarget.setTarget(cs);
+				}
+  	  	catch (IOException iox) {
+					throw new ProcessorException(theTarget, "Failed to read script", iox);
+				}
+				catch (ScriptException sx) {
+					throw new ProcessorException(theTarget, "Failed to compile script", sx);
+				}
+			}
+		}
+
+		return cs;
+	}
+
+	public ContextBuilder process(Catalog theCatalog) {
+		return new ContextBuilder(
+											this.engine.createBindings())
+											//new DelegateBindings(this.engine.getBindings(ScriptContext.ENGINE_SCOPE)))
+								.with("catalog", new JSCatalog(theCatalog));
+	}
+
+	/**
+   */
+	public class ContextBuilder implements ProcessBuilder<JSP> { 
+
+		private ScriptContext		context;
+
+		protected ContextBuilder(Bindings theBindings) {
+			this.context = new SimpleScriptContext();
+			this.context.setBindings(theBindings, Process.PROCESS_SCOPE /*ScriptContext.ENGINE_SCOPE*/);
+		}
+
+		public ContextBuilder withPreprocessing(BiFunction<Target, ScriptContext, Boolean> thePreprocessing) {
+			this.context.setAttribute("preprocessor", thePreprocessing, Process.PROCESS_SCOPE);
+			return this;
+		}
+
+		public ContextBuilder withPostprocessing(BiFunction<Target, ScriptContext, Boolean> thePostprocessing) {
+			this.context.setAttribute("postprocessor", thePostprocessing, Process.PROCESS_SCOPE);
+			return this;
+		}
+
+		public ContextBuilder with(String theName, Object theValue) {
+			this.context.getBindings(Process.PROCESS_SCOPE).put(theName, theValue);
+			return this;
+		}
+		
+		public ContextBuilder withOpt(String theName, Object theValue) {
+			if (theValue != null)
+				this.context.getBindings(Process.PROCESS_SCOPE).put(theName, theValue);
+			return this;
+		}
+
+		public JSProcess process() {
+ 			return new JSProcess(this.context);
+		}
+
+	}
+
+  /**
+   */
+  public class JSProcess implements Process<JSP> {
+
+		private Report											report = new Report();
+		private Iterator<? extends Target> 	scripts;
+		private JScriptInfo									scriptInfo = new JScriptInfo();
+		private	Target											script; //script currently being evaluated
+		private boolean											stopped = false;
+		private ScriptContext								context;
+
+		private JSProcess(ScriptContext theContext) {
+
+			this.context = theContext;
+			this.context.getBindings(Process.PROCESS_SCOPE)
+											.put("stop", new Consumer<String>() {
+																			public void accept(String theMsg) {
+																				JSProcess.this.stopped = true;
+																				//log the message??
+																			}
+																		});
+			this.context.getBindings(Process.PROCESS_SCOPE)
+											.put("report", new Consumer<String>() {
+																			public void accept(String theMsg) {
+																				JSProcess.this.report.add(new ProcessorException(script, theMsg));
+																			}
+																		});
+			this.context.getBindings(Process.PROCESS_SCOPE)
+											.put("reportOnce", new Consumer<String>() {
+																			public void accept(String theMsg) {
+																				JSProcess.this.report.addOnce(new ProcessorException(script, theMsg));
+																			}
+																		});
+			this.scripts = JSP.this.targets.iterator();
+		}
+
+		protected String infoName(Target theTarget) {
+			String name = theTarget.getName();
+			return name.substring(0, name.indexOf(".")) + "_info";
+		}
+
+		public JSP processor() {
+			return JSP.this;
+		}
+
+		public boolean hasNext() {
+			return !this.stopped && this.scripts.hasNext();
+		}
+
+		protected Target next() {
+			if (hasNext())
+				return this.script = this.scripts.next();
+			else
+				throw new RuntimeException("Process is completed");
+		}
+
+		protected boolean runProcessor(String theName) throws ProcessorException {
+			BiFunction<Target, ScriptContext, Boolean> proc = (BiFunction<Target, ScriptContext, Boolean>)
+																														this.context.getAttribute(theName, Process.PROCESS_SCOPE);
+			if (proc != null) {
+				try {
+					return proc.apply(this.script, this.context).booleanValue();
+				}
+				catch (Exception x) {
+					throw new ProcessorException(this.script, theName + "failed", x);
+				}
+			}
+
+			return true;
+		}
+
+		public Process runNext() throws ProcessorException {
+			Target target = next();
+			synchronized(target) {
+				String name = infoName(target);
+				try {
+					if (runProcessor("preprocessor")) {
+						compile(target).eval(this.context);
+						runProcessor("postprocessor");
+					}
+				}
+				catch (ScriptException sx) {
+					throw new ProcessorException(target, "Failed to execute validation script", sx);
+				}
+			}
+			
+			return this;
+		}
+		
+		public Process runNextSilently() {
+			try {
+				return runNext();
+			}
+			catch (ProcessorException px) {
+				this.report.add(px);
+			}
+			return this;
+		}
+
+		public Report run() {
+			while (hasNext())
+				runNextSilently();
+			return this.report;
+		}
+
+		public void stop() {
+			this.stopped = true;
+		}
+
+		public Report report() {
+			return this.report;
+		}
+	}
+
+	private static class JScriptInfo implements TargetInfo {
+	
+		private JSObject info;
+
+		protected JScriptInfo() {
+		}
+
+		protected JScriptInfo setInfo(JSObject theInfo) {
+			this.info = theInfo;
+			return this;
+		}
+
+		public Set<String>	entryNames() {
+			return this.info == null ? Collections.EMPTY_SET : this.info.keySet();
+		}
+
+		public boolean	hasEntry(String theName) {
+			return this.info == null ? false : this.info.hasMember(theName);
+		}
+
+		public Object	getEntry(String theName) {
+			return this.info == null ? null : 
+								 this.info.hasMember(theName) ?	this.info.getMember(theName) : null;
+		}
+	}
+
+
+  /* Exposes the catalog information in a more Java Script friendly manner.
+   */
+  public static class JSCatalog {
+
+		private Catalog catalog;
+
+		private JSCatalog(Catalog theCatalog) {
+			this.catalog = theCatalog;
+		}
+		
+		/** */
+    public JSTarget[] targets() {
+			return 
+				this.catalog.targets()
+					.stream()
+					.map(t -> { return new JSTarget(t); })
+					.toArray(size -> new JSTarget[size]); //or toArray(JSNode[]::new)
+    }
+    
+		public JSTarget[] topTargets() {
+			return 
+				this.catalog.topTargets()
+					.stream()
+					.map(t -> { return new JSTarget(t); })
+					.toArray(size -> new JSTarget[size]); //or toArray(JSNode[]::new)
+    }
+
+		/** */
+    public String[] types(String theConstruct) {
+			Set<String> names = 
+							this.catalog.getConstructTypes(Enum.valueOf(Construct.class,theConstruct)).keySet();
+      return names.toArray(new String[names.size()]);
+    }
+
+		/** */
+		public boolean isDerivedFrom(String theConstruct, String theType, String theSuperType) {
+			return this.catalog.isDerivedFrom(Enum.valueOf(Construct.class,theConstruct), theType, theSuperType);
+		}
+
+		/** */
+		public JSObject facetDefinition(String theConstruct, String theType, String theFacet, String theName) {
+			return new JSElement(theName,
+													 this.catalog.getFacetDefinition(
+															Enum.valueOf(Construct.class, theConstruct), theType, 
+															Enum.valueOf(Facet.class, theFacet), theName));
+		}
+
+
+		/** */
+/*
+    public JSElement[] targetNodes(Target theTarget) {
+			return 
+				this.catalog.getTargetTemplates(theTarget, Construct.Node)
+					.entrySet()
+						.stream()
+						.map(e -> { return new JSElement(e.getKey(),e.getValue()); })
+						.toArray(size -> new JSElement[size]); //or toArray(JSNode[]::new)
+		}
+*/
+
+		public class JSTarget {
+
+			private Target 				tgt;
+	  	private	JXPathContext jxPath;
+
+			private JSTarget(Target theTarget) {
+				this.tgt = theTarget;
+				this.jxPath = JXPathContext.newContext(this.tgt.getTarget());
+				this.jxPath.setLenient(true);
+			}
+
+			public String getName() { return this.tgt.getName(); }
+
+			public JSElement resolve(String thePath) {
+				Object res = jxPath.getValue(thePath);
+				if (res instanceof Map) {
+					return new JSElement(thePath, (Map)res);
+				}
+				//??
+				return null;
+			}
+
+			public JSElement[] getInputs() {
+				
+				Map<String,Map> inputs = (Map<String,Map>)jxPath.getValue("/topology_template/inputs");
+				return (inputs == null) ? 
+										new JSElement[0]
+									: inputs.entrySet()
+											.stream()
+											.map(e -> { return new JSElement(e.getKey(),e.getValue()); })
+											.toArray(size -> new JSElement[size]);
+			}
+
+//			public JSElement[] getOutputs() {
+//			}
+
+      public JSElement getMetadata() {
+				return new JSElement("metadata", (Map)jxPath.getValue("/metadata"));
+			}
+
+			public JSElement[] getNodes() {
+				return 
+					JSCatalog.this.catalog.getTargetTemplates(this.tgt, Construct.Node)
+						.entrySet()
+							.stream()
+							.map(e -> { return new JSElement(e.getKey(),e.getValue()); })
+							.toArray(size -> new JSElement[size]); //or toArray(JSElement[]::new)
+			}
+
+//			public JSElement[] getPolicies() {
+//			}
+
+		}
+
+
+		/*
+		 */
+  	public class JSElement extends AbstractJSObject {
+	
+
+			private String 	name;
+  	  private Map			def;
+
+			private JSElement(String theName, Object theDef) {
+//System.out.println("JSObject " + theName + ":" + theDef);
+				this.name = theName;
+    	  this.def = theDef == null ? Collections.emptyMap() 
+																	: (theDef instanceof Map) ? (Map)theDef
+																														: Collections.singletonMap("value",theDef);
+			}
+
+			public String getName() { return this.name; }
+
+			public boolean hasMember(String theMember) {
+//	System.out.println("hasMember " + theMember);
+				return this.def.containsKey(theMember); 
+			}
+
+			public Object getMember(final String theMember) {
+				Object val = this.def.get(theMember);
+//	System.out.println("getMember " + theMember + ": " + val);
+				if (val != null) {
+					if (val instanceof Map) {
+						return new JSElement(theMember, val);
+					/*
+						return ((Map<String,?>)obj).entrySet()
+											.stream()
+											.map((Map.Entry<String,?> e) -> { return new JSElement(e.getKey(),e.getValue()); })
+											.toArray(size -> new JSElement[size]);
+					*/
+					}
+					
+					if (val instanceof List) {
+						//a property value can be a list of: primitive types or maps (for a user defined type)
+						//requirements are exposed as a list of maps
+						List lval = (List)val;
+						if (lval.get(0) instanceof Map) {
+							return lval
+											.stream()
+											.map((e) -> new JSElement(theMember, e))
+											.toArray(size -> new JSElement[size]);
+							
+						/*
+							return val
+											.stream()
+											.map((e) -> {
+																		System.out.println("Found in " + theMember + ": " + e); 
+																		Map.Entry<String,?> re = ((Map<String,?>)e).entrySet().iterator().next();
+																		return new JSElement(re.getKey(), re.getValue());
+																	})
+											.toArray(size -> new JSElement[size]);
+						*/
+						}
+					}
+					
+					return val;
+				}
+				else {
+					if ("name".equals(theMember))
+						return this.name;
+					if ("toString".equals(theMember))
+						return _toString;
+					if ("hasOwnProperty".equals(theMember))
+						return _hasOwnProperty;	
+//		System.out.println("Could not find " + theMember + " in " + this.def);
+					return super.getMember(theMember);
+				}
+			}		
+			/* TODO: we do not expose 'name' in here */
+			public Set<String> keySet() {
+//				System.out.println("keySet: " + this.def.keySet());
+				return this.def.keySet(); 
+			}
+
+/* having problem with getDefaultValue in Jenkins builds */
+/*
+			public Object getDefaultValue(Class<?> hint) {
+//				System.out.println("getDefaultValue: " + hint);
+				if (String.class.equals(hint))
+					return this.def.toString();
+
+				return super.getDefaultValue(hint);
+			}
+*/
+
+		}
+
+
+	static final JSObject _toString = 
+						new TracerJSObject("_toString") {
+							public Object call(Object thiz, Object... args) {
+								return ((JSElement)thiz).def.toString();
+							}
+
+							public boolean isFunction() { return true; }
+						};
+
+	static final JSObject _hasOwnProperty = 
+						new TracerJSObject("_hasOwnProperty") {
+							public Object call(Object thiz, Object... args) {
+//				System.out.println("_hasOwnProperty: " + args.length);
+								return ((JSElement)thiz).def.containsKey(args[0]);
+							}
+
+							public boolean isFunction() { return true; }
+						};	
+
+	}//JSCatalog
+
+
+
+  private static class TracerJSObject extends AbstractJSObject {
+
+		private String mark;
+	
+		TracerJSObject(String theMark) {
+			this.mark = theMark;
+		}
+
+		public Object call(Object thiz, Object... args)	{
+			System.out.println(this.mark + ":call");
+			return super.call(thiz, args);
+		}
+
+		public Object newObject(Object... args) {
+			System.out.println(this.mark + ":newObject");
+			return super.newObject(args);
+		}
+
+		public Object eval(String s) {
+			System.out.println(this.mark + ":eval");
+			return super.eval(s);
+		}
+
+		public Object getMember(String name) {
+			System.out.println(this.mark + ":getMember");
+			return super.getMember(name);
+		}
+
+		public Object getSlot(int index) {
+			System.out.println(this.mark + ":getSlot");
+			return super.getSlot(index);
+		}
+
+		public boolean hasMember(String name) {
+			System.out.println(this.mark + ":hasMember");
+			return super.hasMember(name);
+		}
+
+		public boolean hasSlot(int slot) {
+			System.out.println(this.mark + ":hasSlot");
+			return super.hasSlot(slot);
+		}
+
+		public void removeMember(String name) {
+			System.out.println(this.mark + ":removeMember");
+			super.removeMember(name);
+		}
+
+		public void setMember(String name, Object value) {
+			System.out.println(this.mark + ":setMember");
+			super.setMember(name,value);
+		}
+
+		public void setSlot(int index, Object value) {
+			System.out.println(this.mark + ":setSlot");
+			super.setSlot(index,value);
+		}
+
+		public Set<String> keySet() {
+			System.out.println(this.mark + "JSObject:keySet");
+			return super.keySet();
+		}
+
+		public Collection<Object> values() {
+			System.out.println(this.mark + ":values");
+			return super.values();
+		}
+
+		public boolean isInstance(Object instance) {
+			System.out.println(this.mark + ":isInstance");
+			return super.isInstance(instance);
+		}
+
+		public boolean isInstanceOf(Object clazz) {
+			System.out.println(this.mark + ":isInstanceOf");
+			return super.isInstance(clazz);
+		}
+
+		public String getClassName() {
+			System.out.println(this.mark + ":getClassName");
+			return super.getClassName();
+		}
+
+		public boolean isFunction() {
+			System.out.println(this.mark + ":isFunction");
+			return super.isFunction();
+    }
+
+		public boolean isStrictFunction() {
+			System.out.println(this.mark + ":isStrictFunction");
+			return super.isStrictFunction();
+		}
+
+		public boolean isArray() {
+			System.out.println(this.mark + ":isArray");
+			return super.isArray();
+		}
+
+		public Object getDefaultValue(Class<?> hint) {
+			System.out.println(this.mark + ":getDefaultValue(" + hint + ")");
+			return super.getDefaultValue(hint);
+		}
+	}
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/Process.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/Process.java
new file mode 100644
index 0000000..865de06
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/Process.java
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.processing;
+
+import java.util.function.Predicate;
+
+import org.onap.tosca.checker.Report;
+
+/**
+ * 
+ */
+public interface Process<T extends Processor> {
+
+	public static final int	PROCESS_SCOPE = 100;
+
+	/**
+   * the processor running this process
+   */
+	public T processor();
+
+  /* */
+	public boolean hasNext();
+
+  /* */
+	public Process runNext() throws ProcessorException;
+
+	/* execute all steps to completion
+   */
+	public Report run();
+
+	/* execution report
+   */
+	public Report report(); 
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/ProcessBuilder.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/ProcessBuilder.java
new file mode 100644
index 0000000..cb0b455
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/ProcessBuilder.java
@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.processing;
+
+import org.onap.tosca.checker.Report;
+
+
+/**
+ * Just in case you might want to do something with a template (set) once it was checked
+ */
+public interface ProcessBuilder<T extends Processor> {
+
+	/* */
+	public ProcessBuilder<T> with(String theName, Object theValue);
+		
+	/* */
+	public ProcessBuilder<T> withOpt(String theName, Object theValue);
+  
+	/* */
+	public Process<T> process();
+
+	/* */
+	default public Report run() {
+		return process()
+						.run();
+	}
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/Processor.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/Processor.java
new file mode 100644
index 0000000..94904d2
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/Processor.java
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.processing;
+
+import org.onap.tosca.checker.Catalog;
+
+
+/**
+ * Just in case you might want to do something with a template (set) once it was checked
+ */
+public interface Processor<T extends Processor<T>> {
+
+  /* */
+	public ProcessBuilder<T> process(Catalog theCatalog);
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/ProcessorException.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/ProcessorException.java
new file mode 100644
index 0000000..2d9cd22
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/ProcessorException.java
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.processing;
+
+import org.onap.tosca.checker.Target;
+import org.onap.tosca.checker.CheckerException;
+
+
+/**
+ */
+public class ProcessorException extends CheckerException {
+
+	private Target	target;
+
+  public ProcessorException(Target theTarget, String theMsg, Throwable theCause) {
+    super(theMsg, theCause);
+		this.target = theTarget;
+  }
+
+  public ProcessorException(Target theTarget, String theMsg) {
+    super(theMsg);
+		this.target = theTarget;
+  }
+
+	public Target getTarget() {
+		return this.target;
+	}
+
+	@Override
+	public String getMessage() {
+		return this.target + ":" + super.getMessage() + (getCause() == null ? "" : ("(" + getCause() + ")"));
+	}
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/TargetInfo.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/TargetInfo.java
new file mode 100644
index 0000000..f330df5
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/TargetInfo.java
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+package org.onap.tosca.checker.processing;
+
+import java.util.Set;
+
+
+/**
+ * Exposes target properties. How they are obtained/calculated not of importance here.
+ */
+public interface TargetInfo {
+	
+	/** */
+	public Set<String>	entryNames();
+
+	/** */
+	public boolean	hasEntry(String theName);
+
+	/** */
+	public Object	getEntry(String theName);
+
+}
diff --git a/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/package-info.java b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/package-info.java
new file mode 100644
index 0000000..7a2d62f
--- /dev/null
+++ b/javatoscachecker/checker/src/main/java/org/onap/tosca/checker/processing/package-info.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2017 <AT&T>.  All rights reserved.
+ * ===================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed 
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for
+ * the specific language governing permissions and limitations under the License.
+ */
+
+/**
+ * After checking and cataloging we assume some applications will do some sort of post-processing.
+ * While all such processing can be done in java by navigating catalog information this package focuses
+ * on processing based on different 'environments' through a so called 'processor'. The package offers one
+ * implementation, a Java Script processor that exposes Checker catalog information to java scripts executed
+ * through Nashorn, the Javs (8) built-in java script engine.
+ *  
+ */
+
+package org.onap.tosca.checker.processing;
diff --git a/javatoscachecker/checker/src/main/resources/org/onap/tosca/checker/messages_en_US.properties b/javatoscachecker/checker/src/main/resources/org/onap/tosca/checker/messages_en_US.properties
new file mode 100644
index 0000000..f1152cc
--- /dev/null
+++ b/javatoscachecker/checker/src/main/resources/org/onap/tosca/checker/messages_en_US.properties
@@ -0,0 +1,18 @@
+EMPTY_TEMPLATE= Empty template
+
+# {0}: field, {1}: field value, {2}: construct
+INVALID_CONSTRUCT_REFERENCE= {0} is expected to be a reference to a {2} type or {2} template, value ''{1}'' is none of those 
+
+INVALID_TYPE_REFERENCE= ''{0}'' value ''{1}'' is expected to be a reference to a {2} type. No {2} type with this name was declared.
+#{0}: field, {1} value, {2} construct
+INVALID_TEMPLATE_REFERENCE= ''{0}'' value ''{1}'' is expected to be a reference to a {2} template.  No such {2} template is in scope.
+INVALID_INTERFACE_REFERENCE= {2} type ''{0}'' has no interface ''{1}''
+#INCOMPATIBLE_TYPE_REFERENCE= {2} type ''{0}'' value ''{1}'' is not type compatible with any declared {2} type
+
+# {0}: the target construct, {1}: target, {2}: target definition
+INCOMPATIBLE_REQUIREMENT_TARGET= Required target {0} type {1} is not compatible with the target {0} type found in the requirement definition {2}
+
+Unknown " + theConstruct + " " + theFacet + " (not declared by the type " + theSpecType + ") were used: " + defs,
+
+#{0}: construct, {1}: facet, {2} type, {3} list of facets
+INVALID_FACET_REFERENCE: Unknown {0} {1} (not available through the type {2}) were used: {3}
\ No newline at end of file
diff --git a/javatoscachecker/checker/src/main/resources/tosca/tosca-common-types.yaml b/javatoscachecker/checker/src/main/resources/tosca/tosca-common-types.yaml
new file mode 100644
index 0000000..cacaa5b
--- /dev/null
+++ b/javatoscachecker/checker/src/main/resources/tosca/tosca-common-types.yaml
@@ -0,0 +1,668 @@
+tosca_definitions_version: tosca_simple_yaml_1_1_0
+description: >
+ TOSCA simple profile common types. To be included by default in all templates.
+
+
+data_types:
+
+#see 5.3.1
+  tosca.datatypes.Root:
+    description: The TOSCA root Data Type all other TOSCA base Data Types derive from
+
+#from 5.3.2
+  tosca.datatypes.Credential:
+    derived_from: tosca.datatypes.Root
+    properties:
+      protocol:
+        type: string
+        required: false
+      token_type:
+        type: string
+        default: password
+      token:
+        type: string
+      keys:
+        type: map
+        required: false
+        entry_schema: string
+      user:
+        type: string
+        required: false
+
+#from 5.3.3
+  tosca.datatypes.TimeInterval:
+    derived_from: tosca.datatypes.Root
+    properties:
+      start_time:
+        type: timestamp
+        required: true
+      end_time:
+        type: timestamp
+        required: true
+
+#from 5.3.4
+  tosca.datatypes.network.NetworkInfo:
+    derived_from: tosca.datatypes.Root
+    properties:
+      network_name:
+        type: string
+      network_id:
+        type: string
+      addresses:
+        type: list
+        entry_schema: string
+
+#from 5.3.5
+  tosca.datatypes.network.PortInfo:
+    derived_from: tosca.datatypes.Root
+    properties:
+      port_name:
+        type: string
+      port_id:
+        type: string
+      network_id:
+        type: string
+      mac_address:
+        type: string
+      addresses:
+        type: list
+        entry_schema: string
+
+#from 5.3.6
+  tosca.datatypes.network.PortDef:
+    derived_from: integer
+    constraints:
+      - in_range: [ 1, 65535 ]
+
+#from 5.3.7
+  tosca.datatypes.network.PortSpec:
+    derived_from: tosca.datatypes.Root
+    properties:
+      protocol:
+        type: string
+        required: true
+        default: tcp
+        constraints:
+          - valid_values: [ udp, tcp, igmp ]
+      target:
+#I think the intent was (same for source):
+#type: tosca.datatypes.network.PortDef
+        type: integer
+        entry_schema: tosca.datatypes.network.PortDef
+      target_range:
+        type: range
+        constraints:
+          - in_range: [ 1, 65535 ]
+      source:
+        type: integer
+        entry_schema: tosca.datatypes.network.PortDef
+      source_range:
+        type: range
+        constraints:
+          - in_range: [ 1, 65535 ]
+
+capability_types:
+
+#from 5.5.1
+  tosca.capabilities.Root:
+    description: The TOSCA root Capability Type all other TOSCA base Capability Types derive from
+
+#from 5.5.2
+  tosca.capabilities.Node:
+    derived_from: tosca.capabilities.Root
+
+#from 5.5.3
+  tosca.capabilities.Compute:
+    derived_from: tosca.capabilities.Root
+    properties:
+      name:
+        type: string
+        required: false
+      num_cpus:
+        type: integer
+        required: false
+        constraints:
+          - greater_or_equal: 1
+      cpu_frequency:
+        type: scalar-unit.frequency
+        required: false
+        constraints:
+          - greater_or_equal: 0.1 GHz
+      disk_size:
+        type: scalar-unit.size
+        required: false
+        constraints:
+          - greater_or_equal: 0 MB
+      mem_size:
+        type: scalar-unit.size
+        required: false
+        constraints:
+          - greater_or_equal: 0 MB
+
+#from 5.5.4
+  tosca.capabilities.Network:
+    derived_from: tosca.capabilities.Root
+    properties:
+      name:
+        type: string
+        required: false
+
+#from 5.5.5
+  tosca.capabilities.Storage:
+    derived_from: tosca.capabilities.Root
+    properties:
+      name:
+        type: string
+        required: false
+
+#from 5.5.6
+  tosca.capabilities.compute.Container:
+    derived_from: tosca.capabilities.Compute
+  
+  tosca.capabilities.Container:
+    derived_from: tosca.capabilities.Compute
+
+#from 5.5.7
+  tosca.capabilities.Endpoint:
+    derived_from: tosca.capabilities.Root
+    properties:
+      protocol:
+        type: string
+        default: tcp
+      port:
+        type: tosca.datatypes.network.PortDef
+        required: false
+      secure:
+        type: boolean
+        default: false
+      url_path:
+        type: string
+        required: false
+      port_name: 
+        type: string
+        required: false
+      network_name:
+        type: string
+        required: false
+        default: PRIVATE
+      initiator:
+        type: string
+        default: source
+        constraints:
+          - valid_values: [ source, target, peer ]
+      ports:
+        type: map
+        required: false
+        constraints:
+          - min_length: 1
+        entry_schema: tosca.datatypes.network.PortSpec
+    attributes:
+      ip_address:
+        type: string
+
+#from 5.5.8
+  tosca.capabilities.Endpoint.Public:
+    derived_from: tosca.capabilities.Endpoint
+    properties:
+      # Change the default network_name to use the first public network found
+      network_name:
+        type: string
+        default: PUBLIC
+      floating:
+        description: >
+          indicates that the public address should be allocated from a pool of floating IPs that are associated with the network.
+        type: boolean
+        default: false
+        status: experimental
+      dns_name:
+        description: The optional name to register with DNS
+        type: string
+        required: false
+        status: experimental
+
+#from 5.5.9
+  tosca.capabilities.Endpoint.Admin:
+    derived_from: tosca.capabilities.Endpoint
+    # Change Endpoint secure indicator to true from its default of false
+    properties:
+      secure:
+        type: boolean
+        default: true
+        constraints:
+          - equal: true
+
+#from 5.5.10
+  tosca.capabilities.Endpoint.Database:
+    derived_from: tosca.capabilities.Endpoint
+
+#from 5.5.11
+  tosca.capabilities.Attachment:
+    derived_from: tosca.capabilities.Root
+
+#from 5.5.12
+  tosca.capabilities.OperatingSystem:
+    derived_from: tosca.capabilities.Root
+    properties:
+      architecture:
+        type: string
+        required: false
+      type:
+        type: string
+        required: false
+      distribution:
+        type: string
+        required: false
+      version:
+        type: version
+        required: false
+
+#from 5.5.13
+  tosca.capabilities.Scalable:
+    derived_from: tosca.capabilities.Root
+    properties:
+      min_instances:
+        type: integer
+        default: 1
+      max_instances:
+        type: integer
+        default: 1
+      default_instances:
+        type: integer
+
+#from C.3.11
+  tosca.capabilities.network.Bindable:
+    derived_from: tosca.capabilities.Node
+
+
+relationship_types:
+
+#from 5.7.1
+  tosca.relationships.Root:
+    description: The TOSCA root Relationship Type all other TOSCA base Relationship Types derive from
+    attributes:
+      tosca_id:
+        type: string
+      tosca_name:
+        type: string
+    interfaces:
+      Configure:
+        type: tosca.interfaces.relationship.Configure
+
+#from 5.7.2
+  tosca.relationships.DependsOn:
+    derived_from: tosca.relationships.Root
+    valid_target_types: [ tosca.capabilities.Node ]
+
+#from 5.7.3
+  tosca.relationships.HostedOn:
+    derived_from: tosca.relationships.Root
+    valid_target_types: [ tosca.capabilities.compute.Container ]
+
+#from 5.7.4
+  tosca.relationships.ConnectsTo:
+    derived_from: tosca.relationships.Root
+    valid_target_types: [ tosca.capabilities.Endpoint ]
+    properties:
+      credential:
+        type: tosca.datatypes.Credential
+        required: false
+
+#from 5.7.5
+  tosca.relationships.AttachesTo:
+    derived_from: tosca.relationships.Root
+    valid_target_types: [ tosca.capabilities.Attachment ]
+    properties:
+      location:
+        type: string
+        constraints:
+          - min_length: 1
+      device:
+        type: string
+        required: false
+
+#from 5.7.6
+  tosca.relationships.RoutesTo:
+    derived_from: tosca.relationships.ConnectsTo
+    valid_target_types: [ tosca.capabilities.Endpoint ]
+
+
+interface_types:
+
+#from 5.8.3
+  tosca.interfaces.Root:
+#    derived_from: tosca.entity.Root
+    description: The TOSCA root Interface Type all other TOSCA base Interface Types derive from
+
+#from 5.8.4
+  tosca.interfaces.node.lifecycle.Standard:
+    derived_from: tosca.interfaces.Root
+    create:
+      description: Standard lifecycle create operation.
+    configure:
+      description: Standard lifecycle configure operation.
+    start:
+      description: Standard lifecycle start operation.
+    stop:
+      description: Standard lifecycle stop operation.
+    delete:
+      description: Standard lifecycle delete operation.
+
+#from 5.8.5
+  tosca.interfaces.relationship.Configure:
+    derived_from: tosca.interfaces.Root
+    pre_configure_source:
+      description: Operation to pre-configure the source endpoint.
+    pre_configure_target:
+      description: Operation to pre-configure the target endpoint.
+    post_configure_source:
+      description: Operation to post-configure the source endpoint.
+    post_configure_target:
+      description: Operation to post-configure the target endpoint.
+    add_target:
+      description: Operation to notify the source node of a target node being added via a relationship.
+    add_source:
+      description: Operation to notify the target node of a source node which is now available via a relationship.
+    target_changed:
+      description: Operation to notify source some property or attribute of the target changed
+    remove_target:
+      description: Operation to remove a target node. 
+
+
+node_types:
+
+#from 5.9.1
+  tosca.nodes.Root:
+    description: The TOSCA Node Type all other TOSCA base Node Types derive from
+    attributes:
+      tosca_id:
+        type: string
+      tosca_name:
+        type: string
+      state:
+        type: string
+    capabilities:
+      feature:
+        type: tosca.capabilities.Node
+    requirements:
+      - dependency:
+          capability: tosca.capabilities.Node
+          node: tosca.nodes.Root
+          relationship: tosca.relationships.DependsOn
+          occurrences: [ 0, UNBOUNDED ]
+    interfaces:
+      Standard:
+        type: tosca.interfaces.node.lifecycle.Standard
+
+#from 5.9.2
+  tosca.nodes.Compute:
+    derived_from: tosca.nodes.Root
+    attributes:
+      private_address:
+        type: string
+      public_address:
+        type: string
+      networks:
+        type: map
+#entry schema for attribute has a string value as per A.5.9 .. 
+#the standard document defines it as a map similar to the property definition ..
+        entry_schema: tosca.datatypes.network.NetworkInfo
+      ports:
+        type: map
+        entry_schema: tosca.datatypes.network.PortInfo
+    requirements:
+      - local_storage:
+          capability: tosca.capabilities.Attachment
+          node: tosca.nodes.BlockStorage
+          relationship: tosca.relationships.AttachesTo
+          occurrences: [0, UNBOUNDED]
+    capabilities:
+      host:
+        type: tosca.capabilities.compute.Container
+        valid_source_types: [tosca.nodes.SoftwareComponent]
+      endpoint:
+        type: tosca.capabilities.Endpoint.Admin
+      os:
+        type: tosca.capabilities.OperatingSystem
+      scalable:
+        type: tosca.capabilities.Scalable
+      binding:
+        type: tosca.capabilities.network.Bindable
+
+#from 5.9.3
+  tosca.nodes.SoftwareComponent:
+    derived_from: tosca.nodes.Root
+    properties:
+      # domain-specific software component version
+      component_version:
+        type: version
+        required: false
+      admin_credential:
+        type: tosca.datatypes.Credential
+        required: false
+    requirements:
+      - host:
+          capability: tosca.capabilities.compute.Container
+          node: tosca.nodes.Compute
+          relationship: tosca.relationships.HostedOn
+
+#from 5.9.4
+  tosca.nodes.WebServer:
+    derived_from: tosca.nodes.SoftwareComponent
+    capabilities:
+    # Private, layer 4 endpoints
+      data_endpoint: tosca.capabilities.Endpoint
+      admin_endpoint: tosca.capabilities.Endpoint.Admin
+      host:
+        type: tosca.capabilities.compute.Container
+        valid_source_types: [ tosca.nodes.WebApplication ]
+
+#from 5.9.5
+  tosca.nodes.WebApplication:
+    derived_from: tosca.nodes.Root
+    properties:
+      context_root:
+        type: string
+    capabilities:
+      app_endpoint:
+        type: tosca.capabilities.Endpoint
+    requirements:
+      - host:
+          capability: tosca.capabilities.compute.Container
+          node: tosca.nodes.WebServer
+          relationship: tosca.relationships.HostedOn
+
+#from 5.9.6
+  tosca.nodes.DBMS:
+    derived_from: tosca.nodes.SoftwareComponent
+    properties:
+      root_password:
+        type: string
+        required: false
+        description: the optional root password for the DBMS service
+      port:
+        type: integer
+        required: false
+        description: the port the DBMS service will listen to for data and requests
+    capabilities:
+      host:
+        type: tosca.capabilities.compute.Container
+        valid_source_types: [ tosca.nodes.Database ]
+
+#from 5.9.7
+  tosca.nodes.Database:
+    derived_from: tosca.nodes.Root
+    properties:
+      name:
+        type: string
+        description: the logical name of the database
+      port:
+        type: integer
+        description: the port the underlying database service will listen to for data
+      user:
+        type: string
+        description: the optional user account name for DB administration
+        required: false
+      password:
+        type: string
+        description: the optional password for the DB user account
+        required: false
+    requirements:
+      - host:
+          capability: tosca.capabilities.compute.Container
+          node: tosca.nodes.DBMS
+          relationship: tosca.relationships.HostedOn
+    capabilities:
+      database_endpoint:
+        type: tosca.capabilities.Endpoint.Database
+
+#from 5.9.8
+  tosca.nodes.ObjectStorage:
+    derived_from: tosca.nodes.Root
+    properties:
+      name:
+        type: string
+      size:
+        type: scalar-unit.size
+        constraints:
+          - greater_or_equal: 0 GB
+      maxsize:
+        type: scalar-unit.size
+        constraints:
+          - greater_or_equal: 0 GB
+    capabilities:
+      storage_endpoint:
+        type: tosca.capabilities.Endpoint
+
+#from 5.9.9
+  tosca.nodes.BlockStorage:
+    derived_from: tosca.nodes.Root
+    properties:
+      size:
+        type: scalar-unit.size
+        constraints:
+          - greater_or_equal: 1 MB
+      volume_id:
+        type: string
+        required: false
+      snapshot_id:
+        type: string
+        required: false
+    capabilities:
+      attachment:
+        type: tosca.capabilities.Attachment
+
+#from 5.9.10
+  tosca.nodes.Container.Runtime:
+    derived_from: tosca.nodes.SoftwareComponent
+    capabilities:
+      host:
+        type: tosca.capabilities.compute.Container
+      scalable:
+        type: tosca.capabilities.Scalable
+
+#from 5.9.11
+  tosca.nodes.Container.Application:
+    derived_from: tosca.nodes.Root
+    requirements:
+      - host:
+          capability: tosca.capabilities.compute.Container
+     #		node: tosca.nodes.Container !invalid node reference!
+          relationship: tosca.relationships.HostedOn
+
+#from 5.9.12
+  tosca.nodes.LoadBalancer:
+    derived_from: tosca.nodes.Root
+    properties:
+      # TBD
+      algorithm:
+        type: string
+        required: false
+        status: experimental
+    capabilities:
+      client:
+        type: tosca.capabilities.Endpoint.Public
+        occurrences: [0, UNBOUNDED]
+        description: the Floating (IP) clients on the public network can connect to
+    requirements:
+      - application:
+          capability: tosca.capabilities.Endpoint
+          relationship: tosca.relationships.RoutesTo
+          occurrences: [0, UNBOUNDED]
+# correction by jora: requirement defintion does not allow for a description entry
+#          description: Connection to one or more load balanced applications
+
+artifact_types:
+
+#from 5.4.1
+  tosca.artifacts.Root:
+    description: The TOSCA Artifact Type all other TOSCA Artifact Types derive from
+
+#from 5.4.2
+  tosca.artifacts.File:
+    derived_from: tosca.artifacts.Root
+
+#from 5.4.3
+  tosca.artifacts.Deployment:
+    derived_from: tosca.artifacts.Root
+    description: TOSCA base type for deployment artifacts
+
+#from 5.4.3.3
+  tosca.artifacts.Deployment.Image:
+    derived_from: tosca.artifacts.Deployment
+
+#from 5.4.3.4
+  tosca.artifacts.Deployment.Image.VM:
+    derived_from: tosca.artifacts.Deployment.Image
+    description: Virtual Machine (VM) Image
+
+#from 5.4.4
+  tosca.artifacts.Implementation:
+    derived_from: tosca.artifacts.Root
+    description: TOSCA base type for implementation artifacts
+
+#from 5.4.4.3
+  tosca.artifacts.Implementation.Bash:
+    derived_from: tosca.artifacts.Implementation
+    description: Script artifact for the Unix Bash shell
+    mime_type: application/x-sh
+    file_ext: [ sh ]
+
+#from 5.4.4.4
+  tosca.artifacts.Implementation.Python:
+    derived_from: tosca.artifacts.Implementation
+    description: Artifact for the interpreted Python language
+    mime_type: application/x-python
+    file_ext: [ py ]
+
+
+#from 5.9
+group_types:
+
+  tosca.groups.Root:
+    description: The TOSCA Group Type all other TOSCA Group Types derive from
+    interfaces:
+      Standard:
+        type: tosca.interfaces.node.lifecycle.Standard
+
+#from 5.10
+policy_types:
+
+  tosca.policies.Root:
+    description: The TOSCA Policy Type all other TOSCA Policy Types derive from
+
+  tosca.policies.Placement:
+    derived_from: tosca.policies.Root
+    description: The TOSCA Policy Type definition that is used to govern placement of TOSCA nodes or groups of nodes. 
+
+  tosca.policies.Scaling:
+    derived_from: tosca.policies.Root
+    description: The TOSCA Policy Type definition that is used to govern scaling of TOSCA nodes or groups of nodes. 
+
+  tosca.policies.Update:
+    derived_from: tosca.policies.Root
+    description: The TOSCA Policy Type definition that is used to govern update of TOSCA nodes or groups of nodes.
+
+  tosca.policies.Performance:
+    derived_from: tosca.policies.Root
+    description: The TOSCA Policy Type definition that is used to declare performance requirements for TOSCA nodes or groups of nodes. 
+
diff --git a/javatoscachecker/checker/src/main/resources/tosca/tosca-examples-types.yaml b/javatoscachecker/checker/src/main/resources/tosca/tosca-examples-types.yaml
new file mode 100644
index 0000000..5eee538
--- /dev/null
+++ b/javatoscachecker/checker/src/main/resources/tosca/tosca-examples-types.yaml
@@ -0,0 +1,117 @@
+tosca_definitions_version: tosca_simple_yaml_1_0_0
+description: >
+ Non-normative type definitions, as per section 8 of TOSCA simple profile.
+
+
+artifact_types:
+
+  tosca.artifacts.Deployment.Image.Container.Docker:
+    derived_from: tosca.artifacts.Deployment.Image
+    description: Docker Container Image
+
+  tosca.artifacts.Deployment.Image.VM.ISO:
+    derived_from: tosca.artifacts.Deployment.Image.VM
+    description: Virtual Machine (VM) image in ISO disk format
+    mime_type: application/octet-stream
+    file_ext: [ iso ]
+
+  tosca.artifacts.Deployment.Image.VM.QCOW2:
+    derived_from: tosca.artifacts.Deployment.Image.VM
+    description: Virtual Machine (VM) image in QCOW v2 standard disk format
+    mime_type: application/octet-stream
+    file_ext: [ qcow2 ]
+
+
+capability_types:
+
+  tosca.capabilities.Container.Docker:
+    derived_from: tosca.capabilities.Container
+    properties:
+      version:
+        type: list
+        required: false
+        entry_schema: version
+      publish_all:
+        type: boolean
+        default: false
+        required: false
+      publish_ports:
+        type: list
+        entry_schema: tosca.datatypes.network.PortSpec
+        required: false
+      expose_ports:
+        type: list
+        entry_schema: tosca.datatypes.network.PortSpec
+        required: false
+      volumes:
+        type: list
+        entry_schema: string
+        required: false
+
+
+node_types:
+  
+  tosca.nodes.Database.MySQL:
+    derived_from: tosca.nodes.Database
+    requirements:
+      - host:
+          capability: tosca.capabilities.Container
+          node: tosca.nodes.DBMS.MySQL
+
+  tosca.nodes.DBMS.MySQL:
+    derived_from: tosca.nodes.DBMS
+    properties:
+      port:
+        type: integer
+        description: reflect the default MySQL server port
+        default: 3306
+      root_password:
+        type: string
+        # MySQL requires a root_password for configuration
+        # Override parent DBMS definition to make this property required
+        required: true
+    capabilities:
+      # Further constrain the ‘host’ capability to only allow MySQL databases
+      host:
+        type: tosca.capabilities.Container
+        valid_source_types: [ tosca.nodes.Database.MySQL ]
+
+  tosca.nodes.WebServer.Apache:
+    derived_from: tosca.nodes.WebServer
+
+  tosca.nodes.WebApplication.WordPress:
+    derived_from: tosca.nodes.WebApplication
+    properties:
+      admin_user:
+        type: string
+      admin_password:
+        type: string
+      db_host:
+        type: string
+    requirements:
+      - database_endpoint:
+          capability: tosca.capabilities.Endpoint.Database
+          node: tosca.nodes.Database
+          relationship: tosca.relationships.ConnectsTo
+
+  tosca.nodes.WebServer.Nodejs:
+    derived_from: tosca.nodes.WebServer
+    properties:
+      # Property to supply the desired implementation in the Github repository
+      github_url:
+        required: no
+        type: string
+        description: location of the application on the github.
+        default: https://github.com/mmm/testnode.git
+    interfaces:
+      Standard:
+        type: tosca.interfaces.node.lifecycle.Standard
+        inputs:
+          github_url:
+            type: string
+
+  tosca.nodes.Container.Application.Docker:
+    derived_from: tosca.nodes.Container.Application
+    requirements:
+      - host:
+          capability: tosca.capabilities.Container.Docker
\ No newline at end of file
diff --git a/javatoscachecker/checker/src/main/resources/tosca/tosca-network-types.yaml b/javatoscachecker/checker/src/main/resources/tosca/tosca-network-types.yaml
new file mode 100644
index 0000000..e4930e0
--- /dev/null
+++ b/javatoscachecker/checker/src/main/resources/tosca/tosca-network-types.yaml
@@ -0,0 +1,103 @@
+tosca_definitions_version: tosca_simple_yaml_1_0_0
+description: >
+ TOSCA simple profile for networking.
+
+metadata:
+  template_name: tosca_simple_networking
+  template_version: "1.0"
+
+#imports:
+#  - tosca-common-types.yaml
+
+node_types:
+
+  tosca.nodes.network.Network:
+    derived_from: tosca.nodes.Root
+    properties:
+      ip_version:
+        type: integer
+        required: false
+        default: 4
+        constraints:
+          - valid_values: [ 4, 6 ]
+      cidr:
+        type: string
+        required: false
+      start_ip:
+        type: string
+        required: false
+      end_ip:
+        type: string
+        required: false
+      gateway_ip:
+        type: string
+        required: false
+      network_name:
+        type: string
+        required: false
+      network_id:
+        type: string
+        required: false
+      segmentation_id:
+        type: string
+        required: false
+      network_type:
+        type: string
+        required: false
+      physical_network:
+        type: string
+        required: false
+    capabilities:
+      link:
+        type: tosca.capabilities.network.Linkable
+
+  tosca.nodes.network.Port:
+    derived_from: tosca.nodes.Root
+    properties:
+      ip_address:
+        type: string
+        required: false
+      order:
+        type: integer
+        required: true
+        default: 0
+        constraints:
+          - greater_or_equal: 0
+      is_default:
+        type: boolean
+        required: false
+        default: false
+      ip_range_start:
+        type: string
+        required: false
+      ip_range_end:
+        type: string
+        required: false
+    requirements:
+      - link:
+          capability: tosca.capabilities.network.Linkable
+          relationship: tosca.relationships.network.LinksTo
+      - binding:
+          capability: tosca.capabilities.network.Bindable
+          relationship: tosca.relationships.network.BindsTo
+
+
+capability_types:
+
+  tosca.capabilities.network.Linkable:
+    derived_from: tosca.capabilities.Node
+ 
+  # also part of common types - used in Compute node type 
+  tosca.capabilities.network.Bindable:
+    derived_from: tosca.capabilities.Node
+
+relationship_types:
+
+  tosca.relationships.network.LinksTo:
+    derived_from: tosca.relationships.DependsOn
+    valid_target_types: [ tosca.capabilities.network.Linkable ]
+
+  tosca.relationships.network.BindsTo:
+    derived_from: tosca.relationships.DependsOn
+    valid_target_types: [ tosca.capabilities.network.Bindable ]
+
diff --git a/javatoscachecker/checker/src/main/resources/tosca/tosca-nfv-types.yaml b/javatoscachecker/checker/src/main/resources/tosca/tosca-nfv-types.yaml
new file mode 100644
index 0000000..fd52f6b
--- /dev/null
+++ b/javatoscachecker/checker/src/main/resources/tosca/tosca-nfv-types.yaml
@@ -0,0 +1,143 @@
+tosca_definitions_version: tosca_simple_profile_for_nfv_1_0_0
+description: >
+ TOSCA simple profile for Network Function Virtualization (NFV).
+
+metadata:
+  template_name: http://docs.oasis-open.org/tosca/tosca-nfv/v1.0/csd01/tosca-nfv-v1.0-csd01.pdf
+  template_version: "1.0"
+
+#imports:
+#  - tosca-common-types.yaml
+
+capability_types:
+
+#from 6.3
+  tosca.capabilities.nfv.VirtualLinkable:
+    derived_from: tosca.capabilities.Root
+
+#from 7.2.1
+  tosca.capabilities.nfv.VirtualBindable:
+    derived_from: tosca.capabilities.Root
+# breaks the virtualbinding requirement in the node type nfv.CP
+#    valid_source_types: [ tosca.nodes.nfv.VDU ]
+
+#from 7.2.2
+  tosca.capabilities.nfv.HA:
+    derived_from: tosca.capabilities.Root
+    valid_source_types: [ tosca.nodes.nfv.VDU ]
+
+#from 7.2.3
+  tosca.capabilities.nfv.HA.ActiveActive:
+    derived_from: tosca.capabilities.nfv.HA
+
+#from 7.2.4
+  tosca.capabilities.nfv.HA.ActivePassive:
+    derived_from: tosca.capabilities.nfv.HA
+
+#from 7.2.5
+  tosca.capabilities.nfv.Metric:
+    derived_from: tosca.capabilities.Root
+
+
+relationship_types:
+
+#from 6.4
+  tosca.relationships.nfv.VirtualLinksTo:
+    derived_from: tosca.relationships.ConnectsTo
+    valid_target_types: [ tosca.capabilities.nfv.VirtualLinkable ]
+
+#from 7.3.1
+  tosca.relationships.nfv.VirtualBindsTo:
+    derived_from: tosca.relationships.ConnectsTo
+    valid_target_types: [ tosca.capabilities.nfv.VirtualBindable]
+
+#from 7.3.2
+  tosca.relationships.nfv.HA:
+    derived_from: tosca.relationships.Root
+    valid_target_types: [ tosca.capabilities.nfv.HA]
+
+#from 7.3.3
+  tosca.relationships.nfv.Monitor:
+    derived_from: tosca.relationships.ConnectsTo
+    valid_target_types: [ tosca.capabilities.nfv.Metric]
+
+
+node_types:
+
+#from 7.4.1
+  tosca.nodes.nfv.VNF:
+    derived_from: tosca.nodes.Root
+    properties:
+      id:
+        type: string
+        description: ID of this VNF
+      vendor:
+        type: string
+        description: name of the vendor who generate this VNF
+      version:
+        type: version
+        description: version of the software for this VNF
+    requirements:
+      - virtualLink:
+          capability: tosca.capabilities.nfv.VirtualLinkable
+
+#from 7.4.2
+  tosca.nodes.nfv.VDU:
+    derived_from: tosca.nodes.SoftwareComponent
+    capabilities:
+      high_availability:
+        type: tosca.capabilities.nfv.HA
+      Virtualbinding:
+        type: tosca.capabilities.nfv.VirtualBindable
+      monitoring_parameter:
+        type: tosca.capabilities.nfv.Metric
+    requirements:
+      - high_availability:
+          capability: tosca.capabilities.nfv.HA
+          relationship: tosca.relationships.nfv.HA
+          occurrences: [ 0, 1 ]
+      - host:
+          capability: tosca.capabilities.Container
+          node: tosca.nodes.Compute
+          relationship: tosca.relationships.HostedOn
+
+#from 7.4.3
+  tosca.nodes.nfv.CP:
+    derived_from: tosca.nodes.Root
+    properties:
+      type:
+        type: string
+        required: false
+    requirements:
+      - virtualLink:
+          capability: tosca.capabilities.nfv.VirtualLinkable
+      - virtualbinding:
+          capability: tosca.capabilities.nfv.VirtualBindable
+    attributes:
+      IP_address:
+        type: string
+#!attributes do not take required ..        required: false
+
+#from 8.1
+  tosca.nodes.nfv.VL:
+    derived_from: tosca.nodes.Root
+    properties:
+      vendor:
+        type: string
+        required: true
+        description: name of the vendor who generate this VL
+    capabilities:
+      virtual_linkable:
+        type: tosca.capabilities.nfv.VirtualLinkable
+
+#from 8.2
+  tosca.nodes.nfv.VL.ELine:
+    derived_from: tosca.nodes.nfv.VL
+
+#from 8.3
+  tosca.nodes.nfv.VL.ELAN:
+    derived_from: tosca.nodes.nfv.VL
+
+#from
+  tosca.nodes.nfv.VL.ETree:
+    derived_from: tosca.nodes.nfv.VL
diff --git a/javatoscachecker/checker/src/main/resources/tosca/tosca_simple_yaml_1_0.grammar b/javatoscachecker/checker/src/main/resources/tosca/tosca_simple_yaml_1_0.grammar
new file mode 100644
index 0000000..56f1eb0
--- /dev/null
+++ b/javatoscachecker/checker/src/main/resources/tosca/tosca_simple_yaml_1_0.grammar
@@ -0,0 +1,1262 @@
+_status_values: &status_values  
+  enum:
+    - supported
+    - unsupported
+    - experimental
+    - deprecated
+
+#I do not know that the lists and maps qualify as 'primitive' ..
+_primitive_types: &primitive_types
+  enum: [string,integer,float,boolean,timestamp,list,map,version,range,scalar-unit.size,scalar_unit.frequency,scalar_unit.time]
+
+#needs custom validation as we have to make sure there are 2 elements and allow for the
+#UNBOUNDED keyword as second element
+_range_definition: &range_definition
+  type: seq
+  name: range_definition
+  sequence:
+    - type: scalar
+
+#see A.5.2
+#this is where the need of verifying the size of a collection (sequence/map) came from
+#this is specified as a sequence where each entry is a map with one entry??
+_constraints_sequence: &constraints_sequence
+  name: constraints_sequence
+  short: 0
+  type: seq
+  sequence:
+    - type: map
+#      length: 1
+      mapping:
+        equal:
+          desc: "Constrains a property or parameter to a value equal to the value declared."
+          type: any
+          required: no
+        greater_than:
+          desc: "Constrains a property or parameter to a value greater than the value declared"
+          type: scalar
+          required: no
+        greater_or_equal:
+          desc: "Constrains a property or parameter to a value greater than or equal to the value declared."
+          type: scalar
+          required: no
+        less_than:
+          desc: "Constrains a property or parameter to a value less than the value declared"
+          type: scalar
+          required: no
+        less_or_equal:
+          desc: "Constrains a property or parameter to a value less than or equal to the value declared."
+          type: scalar
+          required: no
+        in_range:
+          desc: "Constrains a property or parameter to a value in range of (inclusive) the two values declared.
+"
+          type: seq
+#          length: 2
+          sequence:
+            - type: scalar
+          required: no
+        valid_values:
+          desc: "Constrains a property or parameter to a value that is in the list of declared values"
+          type: seq
+          sequence:
+            - type: scalar
+          required: no
+        length:
+          desc: "Constrains the property or parameter to a value of a given length."
+          type: int
+          required: no
+        min_length:
+          desc: "Constrains the property or parameter to a value to a minimum length"
+          type: scalar
+          required: no
+        max_length:
+          desc: "Constrains the property or parameter to a value to a maximum length"
+          type: scalar
+          required: no
+        pattern:    
+          desc: "Constrains the property or parameter to a value that is allowed by the provided regular expression."
+          type: str
+          required: no
+
+# section A.5.3 property_filter_definition
+# it is a constraints sequence that gets attached to a property ..
+_property_filter_definition: &property_filter_definition
+  name: property_filter_definition
+  type: map
+  mapping:
+    =:
+      *constraints_sequence
+
+#section A.5.4 node_filter_definition
+_node_filter_definition: &node_filter_definition
+  type: map
+  name: node_filter_definition
+  mapping:
+    properties:
+      desc: "property names to constraints to be applied to those properties"
+      required: no
+      type: seq
+      sequence:
+         - *property_filter_definition
+#        - type: map
+#          mapping: 
+#            =:
+#              *constraints_sequence
+    capabilities:
+      desc: ""
+      required: no
+      type: seq
+      sequence:
+        - type: map
+          name: node_filter_capabilities_sequence
+          desc: "the key is a capability name or type"
+          mapping:
+            =: 
+              name: node_filter_capabilities_entry
+              type: map
+              mapping:
+                properties:
+                  desc: "the capability properties and their constraints"
+                  name: node_filter_capabilities_properties
+                  type: seq        
+                  sequence:
+                    - type: map
+                      name: node_filter_capabilities_property
+                      mapping:
+                        =: *constraints_sequence
+
+#used in property and attribute definitions
+_entry_schema_definition: &entry_schema_definition
+  desc: "The optional key that is used to declare the name of the Datatype definition for entries of set types such as the TOSCA list or map"
+  name: entry_schema_definition
+  required: no
+  type: map
+  short: type
+  mapping: 
+    "type":
+      desc: "collection element type"
+      required: yes
+      type: str
+    description:
+      required: no
+      type: str
+    constraints:
+      *constraints_sequence
+
+# see section A.5.5
+_artifact_definition: &artifact_definition
+  type: map
+  name: artifact_definition
+  short: implementation # assumes type can be inferred ..
+  mapping:
+    "type":
+      desc: "The required artifact type for the artifact definition"
+      required: yes
+      type: str
+    description:
+      desc: "The optional description for the artifact definition"
+      required: no
+      type: str
+    implementation:
+      desc: "The optional URI string (relative or absolute) which can be used to locate the artifacts file.
+"
+      required: no
+      type: str
+    repository:
+      desc: "The optional name of the repository definition which contains the location of the external repository that contains the artifact"
+      required: no
+      type: str
+    deploy_path:    
+      desc: "The file path the associated file would be deployed into within the target nodes container."
+      required: no
+      type: str
+
+# see section A.5.6
+_repository_definition: &repository_definition
+  type: map
+  name: repository_definition
+  short: url
+  mapping:
+    description:
+      desc: "The optional description for the repository."
+      required: no
+      type: str
+    url:
+      desc: "The required URL or network address used to access the repository"
+      required: yes
+      type: str
+    credential:
+      desc: "The optional Credential used to authorize access to the repository"
+      required: no
+      type: str
+
+#see section 3.5.7
+_import_definition: &import_definition
+  type: map
+  name: import_definition
+  short: file
+  mapping:
+    file:
+      desc: "file URI"
+      required: yes
+      type: str
+    repository:
+      desc: "symbolic name of the repository definition where the imported file can be found"
+      required: no
+      type: str
+    namespace_uri:
+      desc: "namespace URI to that will be applied to type definitions found within the imported file"
+      required: no
+      type: str
+    namespace_prefix:
+      desc: "optional namespace prefix (alias) that will be used to indicate the namespace_uri when forming a qualified name (i.e., qname) when referencing type definitions from the imported"
+      required: no
+      type: str
+
+#see section A.5.7
+_property_definition: &property_definition
+  type: map
+  name: property_definition
+  mapping:
+    "type":
+      type: str
+      required: yes
+#not as easy, it can be an user defined data type
+#      <<: *primitive_types
+    description:
+      type: str
+      required: no
+    constraints:
+      desc: "The optional list of sequenced constraint clauses for the Data Type."
+      required: no
+      <<: *constraints_sequence
+    default:
+      type: any
+      required: no
+    "required":
+      type: bool
+      required: no
+    status:
+      type: str
+      required: no
+      <<: *status_values
+    entry_schema:
+      <<: *entry_schema_definition
+#      desc: "used to declare the name of the Datatype definition for entries of set types such as the TOSCA list or map."
+#      type: str
+#      required: no
+
+#see section A.5.8
+#_property_assignment_definition: &property_assignment_definition
+
+#see A.5.9
+_attribute_definition: &attribute_definition
+  type: map
+  name: attribute_definition
+  mapping:
+    "type":
+      type: str
+      required: yes
+#      <<: *primitive_types
+    description:
+      type: str
+      required: no
+    default:
+      type: any
+      required: no
+    status:
+      desc: "The optional status of the attribute relative to the specification or implementation"
+      type: str
+      required: no
+      <<: *status_values
+    entry_schema:
+      <<: *entry_schema_definition
+
+#see section A.5.10
+#here again, we must support the short form which is the most common
+_attribute_assignment_definition: &attribute_assignment_definition
+  type: map
+  name: attribute_assignment_definition
+  mapping:
+    description:
+      desc: "The optional description of the attribute."
+      required: no
+      type: str
+    value:
+#actually 'value | value_expression'
+      desc: "represent the type-compatible value to assign to the named attribute. Attribute values may be provided as the result from the evaluation of an expression or a function"
+      required: yes
+      type: any
+
+
+# see spec section A.5.11
+
+# see spec section A.5.11.1: variant to be used in node or relationship type definitions 
+_type_operation_definition: &type_operation_definition
+  type: map
+  name: type_operation_definition
+  short: implementation
+  mapping:
+    description:
+      desc: "The optional description string for the associated named operation."
+      required: no
+      type: str
+    implementation:
+      desc: "The optional implementation artifact name (e.g., a script file name within a TOSCA CSAR file)"
+      required: no
+      type: str
+    inputs:
+      desc: ""
+      required: no
+      type: map
+      mapping:
+        =:
+          desc: "a property value or an expression providing a input value"
+          name: property_assignment
+          type: any
+
+# from A.5.11.2
+_template_operation_definition: &template_operation_definition
+  type: map
+  name: template_operation_definition
+  short: implementation
+  mapping:
+    description:
+      desc: "The optional description string for the associated named operation."
+      required: no
+      type: str
+    implementation:
+      desc: "The optional implementation artifact name (e.g., a script file name within a TOSCA CSAR file)"
+      name: template_operation_implementation_definition
+      required: no
+      short: primary
+      type: map
+      mapping:
+        primary:
+          desc: "The optional implementation artifact name (e.g., the primary script file name within a TOSCA CSAR file). "
+          required: no
+          type: str
+        dependencies:
+          desc: "The optional list of one or more dependent or secondary implementation artifact name which are referenced by the primary implementation artifact (e.g., a library the script installs or a secondary script)"
+          required: no
+          type: seq
+          sequence: 
+            - type: str
+    inputs:
+      desc: ""
+      required: no
+      type: map
+      mapping:
+        =:
+          desc: "a property value or an expression providing a input value"
+          name: property_assignment
+          type: any
+
+
+# see section A.5.12, specifically A.5.12.2.1 : definition to be used in node or relationship type definition
+_type_interface_definition: &type_interface_definition
+  type: map
+  name: type_interface_definition
+  mapping:
+    "type":
+      desc: "represents the required name of the Interface Type for the interface definition
+"
+      required: yes
+      type: str
+    inputs:
+      desc: "The optional list of input property definitions available to all defined operations"
+      type: map
+      mapping:
+        =:
+          *property_definition
+    =:
+      *type_operation_definition
+
+# see section A.5.12.2.2, extended notation to be used in node or relationship template definitions
+_template_interface_definition: &template_interface_definition
+  type: map
+  name: template_interface_definition
+  mapping:
+    inputs:
+      desc: "The optional list of input property definitions available to all defined operations"
+      type: map
+      mapping:
+        =:
+          desc: "a property value or an expression providing a property value"
+          name: property_assignment
+          type: any
+    =:
+      *template_operation_definition
+
+
+# A.6 section: type specific definitions
+
+# see section A.6.1
+_capability_definition: &capability_definition
+  type: map
+  name: capability_definition
+  short: type
+  mapping:
+    "type":
+      desc: "The required name of the Capability Type the capability definition is based upon"
+      required: yes
+      type: str
+    description:
+      desc: "The optional description of the Capability definition"
+      required: no
+      type: str
+    properties:
+      desc: ""
+      required: no
+      type: map
+      mapping:
+       =:
+          *property_definition
+    attributes:
+      desc: "An optional list of property definitions for the Capability definition"
+      required: no
+      type: map
+      mapping:
+        =:
+          *attribute_definition
+    valid_source_types:
+      desc: ""
+      required: no
+      type: seq
+      sequence:
+        - type: str
+    occurrences:
+      desc: "The optional minimum and maximum occurrences for the capability."
+      required: no
+      <<: *range_definition
+
+# see section A.6.2
+#
+_requirement_definition: &requirement_definition
+  type: map
+  name: requirement_definition
+  short: capability  #as per A.6.2.2.1
+  mapping:
+    capability:
+      desc: "The required reserved keyname used that can be used to provide the name of a valid Capability Type that can fulfil the requirement"
+      required: yes
+      type: str
+    node:
+      desc: "The optional reserved keyname used to provide the name of a valid Node Type that contains the capability definition that can be used to fulfil the requirement. "
+      required: no
+      type: str
+    relationship:
+# and from section A.6.2.1, this one is an oddball
+      desc: "The optional reserved keyname used to provide the name of a valid Relationship Type to construct when fulfilling the requirement."
+      required: no
+      name: requirement_relationship_definition
+      short: type
+      type: map
+      mapping:
+        type:
+          desc: "The optional reserved keyname used to provide the name of the Relationship Type for the requirement definitions relationship keyname.
+"
+          required: yes
+          type: str
+        interfaces:
+          #not clear which interface definition is to be used here
+          desc: "allows augmentation (additional properties and operations) of the interfaces defined by the relationship type indicated above"
+          required: no
+          type: map
+          mapping:
+            =:
+              *type_interface_definition
+    occurrences:
+      desc: "The optional minimum and maximum occurrences for the requirement."
+      required: no
+      <<: *range_definition
+
+# see section A.6.3
+_artifact_type_definition: &artifact_type_definition
+  type: map
+  name: artifact_type_definition
+  mapping:
+    derived_from:
+      desc: "An optional parent Artifact Type name the Artifact Type derives from"
+      required: no
+      type: str
+    description:
+      desc: "An optional description for the Artifact Type."
+      required: no
+      type: str
+    mime_type:
+      desc: "The required mime type property for the Artifact Type."
+      required: no
+      type: str
+    file_ext:
+      desc: "The required file extension property for the Artifact Type"
+      required: no
+      type: seq
+      sequence:
+        - type: str
+    properties:
+      desc: "An optional list of property definitions for the Artifact Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          *property_definition
+
+#see spec section #A.6.4
+_interface_type_definition: &interface_type_definition
+  type: map
+  name: interface_type_definition
+  mapping:
+    inputs:
+      desc: "The optional list of input property definitions available to all defined operations"
+      type: map
+      mapping:
+        =:
+          type: str
+          desc: "property_name to property_value(_expression) mapping"
+    =:
+      *type_operation_definition
+
+# A.6.5
+_data_type_definition: &data_type_definition
+  type: map
+  name: data_type_definition
+  mapping:
+    derived_from:
+      desc: "The optional key used when a datatype is derived from an existing TOSCA Data Type.
+"
+      required: no
+      type: str
+    description:
+      desc: "The optional description for the Data Type.
+"
+      required: no
+      type: str
+    constraints:
+      desc: "The optional list of sequenced constraint clauses for the Data Type."
+      <<: *constraints_sequence
+    properties:
+      desc: "The optional list property definitions that comprise the schema for a complex Data Type in TOSCA"
+      type: map
+      mapping:
+        =:
+          *property_definition
+
+# see section A.6.6
+_capability_type_definition: &capability_type_definition
+  type: map
+  name: capability_type_definition
+  mapping:
+    derived_from:
+      desc: "An optional parent capability type name this new Capability Type derives from."
+      required: no
+      type: str
+    description:
+      desc: "An optional description for the Capability Type"
+      required: no
+      type: str
+    properties:
+      desc: "An optional list of property definitions for the Capability Type."
+      required: no
+      type: map
+      mapping:
+        =:
+          *property_definition
+    attributes:
+      desc: "An optional list of attribute definitions for the Capability Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          *attribute_definition
+    valid_source_types:
+      desc: "An optional list of one or more valid names of Node Types that are supported as valid sources of any relationship established to the declared Capability Type"
+      required: no
+      type: seq
+      sequence:
+        - type: str
+
+# section A.6.7 requirement definition: TOSCA YAML profile relies on capability types to 
+# define requirements 
+
+# see section A.6.9
+_relationship_type_definition: &relationship_type_definition
+  type: map
+  name: relationship_type_definition
+  mapping:
+    derived_from:
+      desc: "An optional parent Relationship Type name the Relationship Type derives from"
+      required: no
+      type: str
+    description:
+      desc: "An optional description for the Relationship Type."
+      required: no
+      type: str
+    properties:
+      desc: "An optional list of property definitions for the Relationship Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          *property_definition
+    attributes:
+      desc: "An optional list of attribute definitions for the Relationship Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          *attribute_definition
+    interfaces:
+      desc: "An optional list of interface definitions interfaces supported by the Relationship Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          *type_interface_definition
+    valid_target_types:
+      desc: "An optional list of one or more names of Capability Types that are valid targets for this relationship. "
+      required: no
+      type: seq
+      sequence:
+        - type: str
+
+#see section 3.6.10
+_group_type_definition: &group_type_definition
+  type: map
+  name: group_type_definition
+  mapping:
+    derived_from:
+      desc: "An optional parent Group Type name this new Group Type derives from"
+      required: no
+      type: str
+    version:
+      desc: "An optional version for the Group Type definition"
+      required: no
+      type: str
+    description:
+      desc: "An optional description for the Group Type"
+      required: no
+      type: str
+    properties:
+      desc: "An optional list of property definitions for the Group Type."
+      required: no
+      type: map
+      mapping:
+        =:
+          *property_definition
+    targets:
+      desc: "An optional list of one or more names of Node Types that are valid
+(allowed) as members of the Group Type."
+      required: no
+      type: seq
+      sequence:
+        - type: str
+    interfaces:
+      desc: "An optional list of interface definitions supported by the Group Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          *type_interface_definition
+
+#see section 3.6.11
+_policy_type_definition: &policy_type_definition
+  type: map
+  name: policy_type_definition
+  mapping:
+    derived_from:
+      desc: "An optional parent Policy Type name this new Policy Type derives from"
+      required: no
+      type: str
+    version:
+      desc: "An optional version for the Policy Type definition"
+      required: no
+      type: str
+    description:
+      desc: "An optional description for the Policy Type"
+      required: no
+      type: str
+    properties:
+      desc: "An optional list of property definitions for the Policy Type."
+      required: no
+      type: map
+      mapping:
+        =:
+          *property_definition
+    targets:
+      desc: "An optional list of valid Node Types or Group Types the Policy Type
+can be applied to"
+      required: no
+      type: seq
+      sequence:
+        - type: str
+
+# see section A.6.8
+_node_type_definition: &node_type_definition
+  type: map
+  name: node_type_definition
+  mapping:
+    derived_from:
+      desc: "An optional parent Node Type name this new Node Type derives from"
+      required: no
+      type: str
+    description:
+      desc: "An optional description for the Node Type"
+      required: no
+      type: str
+    properties:
+      desc: "An optional list of property definitions for the Node Type."
+      required: no
+      type: map
+      mapping:
+        =:
+          *property_definition
+    attributes:
+      desc: "An optional list of attribute definitions for the Node Type.
+"
+      required: no
+      type: map
+      mapping:
+        =:
+          *attribute_definition
+    requirements:
+      desc: "An optional sequenced list of requirement definitions for the Node Type.
+"
+      required: no
+      type: seq
+      sequence:
+        - type: map
+          mapping:
+            =:
+              *requirement_definition
+    capabilities:
+      desc: "An optional list of capability definitions for the Node Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          *capability_definition
+    interfaces:
+      desc: ""
+      required: no
+      type: map
+      mapping:
+        =:
+          *type_interface_definition
+    artifacts:
+      desc: "An optional list of named artifact definitions for the Node Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          *artifact_definition
+
+# A.7 Template specific definitions
+
+# see section A.7.1
+_capability_assignment_definition: &capability_assignment_definition
+  type: map
+  name: capability_assignment_definition
+  mapping:
+    properties:
+      # list of property assignments
+      desc: "An optional list of property definitions for the Capability definition"
+      required: no
+      type: map
+      mapping:
+        =:
+          desc: "a property value or an expression providing a property value"
+          name: property_assignment
+          type: any
+    attributes:
+      # list of attribute assignments
+      desc: "An optional list of attribute definitions for the Capability definition"
+      required: no
+      type: map
+      mapping:
+        =:
+          desc: ""
+          name: attribute_assignment
+          type: any
+
+# see section A.7.2
+_requirement_assignment_definition: &requirement_assignment_definition
+  type: map
+  name: requirement_assignment_definition
+  short: node
+  mapping:
+    capability:
+      desc: " used to provide the name of either a: Capability definition within a target node template that can fulfill the requirement or Capability Type that the provider will use to select a type-compatible target node template to fulfill the requirement at runtime."
+      required: no
+      type: str
+    node:
+#why is this a reference to a node type and not to a node template??
+      desc: "used to identify the target node of a relationship: Node Template name that can fulfil the target node requirement or Node Type name that the provider will use to select a type-compatible node template to fulfil the requirement at runtime"
+      required: no
+      type: str
+    relationship:
+      desc: ""
+      required: no
+#fins a better name      name: relationship_definition
+      type: map
+      short: type
+      mapping:
+        "type":
+          desc: "The optional reserved keyname used to provide the name of the Relationship Type for the requirement assignments relationship keyname"
+          required: no
+          type: str
+        properties:
+          desc: ""
+          required: no
+          type: map
+          mapping:
+            =:
+              desc: "a property value or an expression providing a property value"
+              name: property_assignment
+              type: any
+        interfaces:
+          desc: "from A.5.12.2.2, right?"
+          required: no
+          type: map
+          mapping:
+            =:
+              *template_interface_definition
+    node_filter:
+      desc: "The optional filter definition that TOSCA orchestrators or providers would use to select a type-compatible target node that can fulfill the associated abstract requirement at runtime."
+      required: no
+      <<: *node_filter_definition
+
+# see section A.7.3
+_node_template_definition: &node_template_definition
+  type: map
+  name: node_template_definition
+  mapping:
+    "type":
+      desc: "The required name of the Node Type the Node Template is based upon"
+      required: yes
+      type: str
+    description:
+      desc: "An optional description for the Node Template"
+      required: no
+      type: str
+    directives:
+      desc: "An optional list of directive values to provide processing instructions to orchestrators and tooling."
+      required: no
+      type: seq
+      sequence:
+        - type: str
+    properties:
+#custom check needs to be added: the value or expression providing the property value
+#needs to be compatible with the property definition
+      desc: "An optional list of property value assignments for the Node Template."
+      required: no
+      type: map
+      mapping:
+        =:
+          type: any
+          name: property_assignment
+          desc: "a property value or an expression providing a property value"
+    attributes:
+      desc: "An optional list of attribute value assignments for the Node Template"
+      required: no
+      type: map
+      mapping:
+        =:
+          *attribute_assignment_definition
+    requirements:
+      desc: "An optional sequenced list of requirement assignments for the Node Template."
+      required: no
+      type: seq
+      sequence:
+        - type: map
+          mapping:
+            =:
+              *requirement_assignment_definition
+    capabilities:
+      desc: "An optional list of capability assignments for the Node Template."
+      required: no
+      type: map
+      mapping:
+        =:
+          *capability_assignment_definition
+    interfaces:
+      desc: "An optional list of named interface definitions for the Node Template"
+      required: no
+      type: map
+      mapping:
+        =:
+          *template_interface_definition
+    artifacts:
+      desc: "An optional list of named artifact definitions for the Node Template.
+"
+      required: no
+      type: map
+      mapping:
+        =:
+          *artifact_definition
+    node_filter:
+      desc: "The optional filter definition that TOSCA orchestrators would use to select the correct target node. This keyname is only valid if the directive has the value of 'selectable' set."
+      required: no
+      <<: *node_filter_definition 
+    copy:
+      desc: "The optional (symbolic) name of another node template to copy into (all keynames and values) and use as a basis for this node template."
+      required: no
+      type: str
+
+# see section A.7.4
+_relationship_template_definition: &relationship_template_definition
+  type: map
+  name: relationship_template_definition
+  mapping:
+    "type":
+      desc: "The required name of the Relationship Type the Relationship Template is based upon"
+      required: yes
+      type: str
+    alias:
+      desc: "The optional name of a different Relationship Template definition whose values are (effectively) copied into the definition for this Relationship Template (prior to any other overrides)."
+      required: no
+      type: str
+    description:
+      desc: "An optional description for the Relationship Template"
+      required: no
+      type: str
+    properties:
+      desc: "An optional list of property assignments for the Relationship Template."
+      required: no
+      name: properties_assignment_validation
+      type: map
+      mapping:
+        =:
+          type: any
+#scalar
+          desc: "an expression providing a property value"
+    attributes:
+      desc: "An optional list of attribute value assignments for the Relationship Template"
+      required: no
+      name: attributes_assignment_validation
+      type: map
+      mapping:
+        =: 
+          type: scalar
+          desc: "an expression providing an attribute value"
+    interfaces:
+      desc: "An optional list of named interface definitions for the Relationship Template ('augmentation' is allowed here)"
+      required: no
+      type: map
+      mapping:
+        =:
+          *template_interface_definition
+    copy:
+      desc: "The optional (symbolic) name of another relationship template to copy into (all keynames and values) and use as a basis for this relationship template."
+      required: no
+      type: str
+
+
+# see section 3.7.5
+_group_definition: &group_definition
+  type: map
+  name: group_definition
+  mapping:
+    "type":
+      desc: "The required name of the group type the group definition is based upon"
+      required: yes
+      type: str
+    description:
+      desc: "The optional description for the group definition"
+      required: no
+    properties:
+      desc: " represents the optional list of property assignments for the group definition that provide values for properties defined in its declared Group Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          type: any
+          name: property_assignment
+    targets:
+      desc: "contains the required list of one or more node template names (within the same topology template) that are members of this logical group"
+      required: yes
+      type: seq
+      sequence:
+        - type: str
+    interfaces:
+      desc: "represents the optional list of interface definitions for the group definition that augment those provided by its declared Group Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          *template_interface_definition
+
+# see section 3.7.6
+_policy_template_definition: &policy_template_definition
+  type: map
+  name: policy_definition
+  mapping:
+    "type":
+      desc: "The required name of the policy type the policy definition is based upon"
+      required: yes
+      type: str
+    description:
+      desc: "The optional description for the policy definition"
+      required: no
+    properties:
+      desc: "represents the optional list of property assignments for the policy definition that provide values for properties defined in its declared Policy Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          type: any
+          name: property_assignment
+    targets:
+      desc: "represents the optional list of names of node templates or groups that the policy is to applied to"
+      required: no
+      type: seq
+      sequence:
+        - type: str
+
+# see section 3.8 Topology Template definition:  defines the topology template of a cloud application.
+# described as a a reusable grammar as it can be a part of a service template definition 
+_topology_template_definition: &topology_template_definition
+  type: map
+  name: topology_template_definition
+  mapping:
+    description:
+      desc: "a description of the topology template"
+      required: no
+      type: str
+    inputs:
+      desc: "definition of input parameters for the topology template"
+      name: inputs
+      required: no
+      type: map
+      mapping:
+        =:
+          *property_definition
+    node_templates:
+      desc: "definition of the node templates of the topology"
+      name: node_templates
+      required: no
+      type: map
+      mapping:
+        =:
+          *node_template_definition
+    relationship_templates:
+      desc: "definition of the relationship templates of the topology"
+      required: no
+      name: relationship_templates
+      type: map
+      mapping:
+        =:
+          *relationship_template_definition
+    outputs:
+      desc: "definition of output parameters for the topology template"
+      name: outputs
+      required: no
+      type: map
+      mapping:
+        =:
+          *attribute_assignment_definition
+    groups:
+      desc: "An optional list of Group definitions whose members are node templates defined within this same Topology Template"
+      name: groups
+      required: no
+      type: map
+      mapping:
+        =:
+          *group_definition
+    policies:
+ # see 8.2.3, initially the list is not described as sequenced but then the grammar shows it as such !?
+      desc: "An optional sequenced?? list of Policy definitions for the Topology Template."
+      name: policies
+      required: no
+      type: seq
+      sequence:
+        - type: map
+          mapping:
+            =:
+              *policy_template_definition
+    substitution_mappings:
+# one possible short-coming that is visible here is that the definition of the capability
+# and requirements mappings are given in the spec only with the short/inline version of a 
+# YAML list/sequence, which cannot be enforced here .. 
+      desc: " a description of the topology template"
+      name: substitution_mappings
+      required: no
+      type: map
+      mapping:
+        node_type:
+          desc: "node type name"
+          required: yes
+          type: str
+        capabilities:
+          desc: "map_of_capability_mappings_to_expose"
+          type: map
+          mapping:
+            =:
+              type: seq
+              sequence:
+                - type: str
+        requirements:      
+          desc: "map_of_requirement_mapping_to_expose"
+          type: map
+          mapping:
+            =:
+              type: seq
+              sequence:
+                - type: str
+
+
+# see A.9 Service Template definition: A TOSCA Service Template (YAML) document contains
+# element definitions of building blocks for cloud application, or complete models of cloud applications. 
+
+type: map
+name: service_template_definition
+mapping:
+  tosca_definitions_version:
+    desc: "Required TOSCA Definitions version string"
+    required: yes
+    type: str
+    enum: [tosca_simple_yaml_1_0, tosca_simple_yaml_1_0_0]
+
+  tosca_default_namespace:
+    desc: "Optional. default namespace (for type schema)"
+    required: no
+    type: str
+
+  metadata:
+    desc: "Optional metadata keyname: value pairs"
+    name: metadata
+    required: no
+    type: map
+    mapping:
+      template_name:
+        desc: "Optional name of this service template"
+        required: no
+        type: str
+      template_author:
+        desc: "Optional author of this service template"
+        required: no
+        type: str
+      template_version:
+        desc: "Optional version of this service template"
+        required: no
+        type: str
+      =:
+        desc: "User defined entry"
+        required: no
+        type: str
+
+#to add, the spec says: "Optional list of domain or profile specific metadata keynames"
+
+  description:
+    desc: "Optional description of the definitions inside the file"
+    required: no
+    type: str
+
+  imports:
+    desc: "ordered list of import statements for importing other definitions files"
+    name: imports
+    required: no
+    type: seq
+    sequence:
+      - type: map
+        mapping:
+          =:
+            *import_definition
+
+  dsl_definitions:
+    desc: "list of YAML alias anchors (or macros)"
+    name: dsl_definitions
+    required: no
+    type: map
+    mapping:
+      =:
+        desc: "some piece of valid yaml that makes the anchor/alias definition" 
+        type: any
+        required: no
+
+  repositories:
+    desc: "list of external repository definitions which host TOSCA artifacts"
+    name: repositories
+    required: no
+    type: map
+    mapping:
+      =:
+        *repository_definition
+
+  data_types:
+    desc: "list of TOSCA datatype definitions"
+    name: data_types
+    required: no
+    type: map
+    mapping:
+      =:
+        *data_type_definition
+
+  node_types:
+    desc: "list of node type definitions"
+    name: node_types
+    required: no
+    type: map
+    mapping:
+      =:
+        *node_type_definition
+
+  capability_types:
+    desc: "list of capability type definitions"
+    name: capability_types
+    required: no
+    type: map
+    mapping:
+      =:
+        *capability_type_definition
+
+  relationship_types:
+    desc: "list of relationship type definitions"
+    name: relationship_types
+    required: no
+    type: map
+    mapping:
+      =:
+        *relationship_type_definition
+
+  artifact_types:
+    desc: "list of artifact type definitions"
+    name: artifact_types
+    required: no
+    type: map
+    mapping:
+      =:
+        *artifact_type_definition
+
+  interface_types:
+    desc: "list of interface type definitions"
+    name: interface_types
+    required: no
+    type: map
+    mapping:
+      =:
+        *interface_type_definition
+
+  group_types:
+    desc: "list of group type definitions"
+    name: group_types
+    required: no
+    type: map
+    mapping:
+      =:
+        *group_type_definition
+
+  policy_types:
+    desc: "list of policy type definitions"
+    name: policy_types
+    required: no
+    type: map
+    mapping:
+      =:
+        *policy_type_definition
+
+  topology_template:
+    desc: "topology template definition of the cloud application or service"
+    required: no
+    <<: *topology_template_definition
diff --git a/javatoscachecker/checker/src/main/resources/tosca/tosca_simple_yaml_1_1.grammar b/javatoscachecker/checker/src/main/resources/tosca/tosca_simple_yaml_1_1.grammar
new file mode 100644
index 0000000..e199680
--- /dev/null
+++ b/javatoscachecker/checker/src/main/resources/tosca/tosca_simple_yaml_1_1.grammar
@@ -0,0 +1,1646 @@
+_status_values: &status_values  
+  enum:
+    - supported
+    - unsupported
+    - experimental
+    - deprecated
+
+#I do not know that the lists and maps qualify as 'primitive' ..
+_primitive_types: &primitive_types
+  enum: [string,integer,float,boolean,timestamp,list,map,version,range,scalar-unit.size,scalar_unit.frequency,scalar_unit.time]
+
+#needs custom validation as we have to make sure there are 2 elements and allow for the
+#UNBOUNDED keyword as second element
+_range_definition: &range_definition
+  desc: "Section used to declare additional metadata information"
+  required: no
+  type: seq
+  size: 2
+  name: range_definition
+  sequence:
+    - type: scalar
+
+_version_definition: &version_definition
+  desc: "An optional TOSCA version number"
+  required: no
+  type: str
+  name: version_definition
+#  pattern: <major_version>.<minor_version>[.<fix_version>[.<qualifier>[-<build_version] ] ]
+
+#common metadata defintion syntax
+_metadata_definition: &metadata_definition
+  desc: "Section used to declare additional metadata information"
+  required: no
+  type: map
+  mapping:
+    =:
+      type: str
+
+#see A.5.2
+#this is where the need of verifying the size of a collection (sequence/map) came from
+#this is specified as a sequence where each entry is a map with one entry??
+_constraints_sequence: &constraints_sequence
+  name: constraints_sequence
+  short: 0
+  type: seq
+  sequence:
+    - type: map
+#      length: 1
+      mapping:
+        equal:
+          desc: "Constrains a property or parameter to a value equal to the value declared."
+          type: any
+          required: no
+        greater_than:
+          desc: "Constrains a property or parameter to a value greater than the value declared"
+          type: scalar
+          required: no
+        greater_or_equal:
+          desc: "Constrains a property or parameter to a value greater than or equal to the value declared."
+          type: scalar
+          required: no
+        less_than:
+          desc: "Constrains a property or parameter to a value less than the value declared"
+          type: scalar
+          required: no
+        less_or_equal:
+          desc: "Constrains a property or parameter to a value less than or equal to the value declared."
+          type: scalar
+          required: no
+        in_range:
+          desc: "Constrains a property or parameter to a value in range of (inclusive) the two values declared."
+          type: seq
+#          length: 2
+          sequence:
+            - type: scalar
+          required: no
+        valid_values:
+          desc: "Constrains a property or parameter to a value that is in the list of declared values"
+          type: seq
+          sequence:
+            - type: scalar
+          required: no
+        length:
+          desc: "Constrains the property or parameter to a value of a given length."
+          type: int
+          required: no
+        min_length:
+          desc: "Constrains the property or parameter to a value to a minimum length"
+          type: scalar
+          required: no
+        max_length:
+          desc: "Constrains the property or parameter to a value to a maximum length"
+          type: scalar
+          required: no
+        pattern:    
+          desc: "Constrains the property or parameter to a value that is allowed by the provided regular expression."
+          type: str
+          required: no
+
+# section A.5.3 property_filter_definition
+# it is a constraints sequence that gets attached to a property ..
+_property_filter_definition: &property_filter_definition
+  name: property_filter_definition
+  type: map
+  mapping:
+    =:
+      *constraints_sequence
+
+#section A.5.4 node_filter_definition
+_node_filter_definition: &node_filter_definition
+  type: map
+  name: node_filter_definition
+  mapping:
+    properties:
+      desc: "property names to constraints to be applied to those properties"
+      required: no
+      type: seq
+      sequence:
+         - *property_filter_definition
+#        - type: map
+#          mapping: 
+#            =:
+#              *constraints_sequence
+    capabilities:
+      desc: ""
+      required: no
+      type: seq
+      sequence:
+        - type: map
+          name: node_filter_capabilities_sequence
+          desc: "the key is a capability name or type"
+          mapping:
+            =: 
+              name: node_filter_capabilities_entry
+              type: map
+              mapping:
+                properties:
+                  desc: "the capability properties and their constraints"
+                  name: node_filter_capabilities_properties
+                  type: seq        
+                  sequence:
+                    - type: map
+                      name: node_filter_capabilities_property
+                      mapping:
+                        =: *constraints_sequence
+
+#used in property and attribute definitions
+_entry_schema_definition: &entry_schema_definition
+  desc: "The optional key that is used to declare the name of the Datatype definition for entries of set types such as the TOSCA list or map"
+  name: entry_schema_definition
+  required: no
+  type: map
+  short: type
+  mapping: 
+    "type":
+      desc: "collection element type"
+      required: yes
+      type: str
+    description:
+      required: no
+      type: str
+    constraints:
+      *constraints_sequence
+
+# see section 3.5.6
+# it is strange that an artifact type defined a set of properties but here there is no place for their assignments ..
+_artifact_definition: &artifact_definition
+  type: map
+  name: artifact_definition
+  short: implementation # assumes type can be inferred ..
+  mapping:
+    "type":
+      desc: "The required artifact type for the artifact definition"
+      required: yes
+      type: str
+    description:
+      desc: "The optional description for the artifact definition"
+      required: no
+      type: str
+    file:
+      desc: "The optional URI string (relative or absolute) which can be used to locate the artifacts file."
+      required: no
+      type: str
+    repository:
+      desc: "The optional name of the repository definition which contains the location of the external repository that contains the artifact"
+      required: no
+      type: str
+    deploy_path:    
+      desc: "The file path the associated file would be deployed into within the target nodes container."
+      required: no
+      type: str
+
+# see section 3.5.5
+_repository_definition: &repository_definition
+  type: map
+  name: repository_definition
+  short: url
+  mapping:
+    description:
+      desc: "The optional description for the repository."
+      required: no
+      type: str
+    url:
+      desc: "The required URL or network address used to access the repository"
+      required: yes
+      type: str
+    credential:
+      #this is the specification of the data type tosca.datatypes.Credential
+      desc: "The optional Credential used to authorize access to the repository"
+      required: no
+      type: map
+      mapping:
+        protocol:
+          required: no
+          type: str
+        token_type:
+          required: no
+          type: str
+          #default: password
+        token:
+          required: no
+          type: str
+        keys:
+          required: no
+          type: map
+          mapping:
+            =:
+              type: str
+        user:
+          required: no
+          type: str
+
+#see section 3.5.7
+_import_definition: &import_definition
+  type: map
+  name: import_definition
+  short: file
+  mapping:
+    file:
+      desc: "file URI"
+      required: yes
+      type: str
+    repository:
+      desc: "symbolic name of the repository definition where the imported file can be found"
+      required: no
+      type: str
+    namespace_uri:
+      desc: "namespace URI to that will be applied to type definitions found within the imported file"
+      required: no
+      type: str
+    namespace_prefix:
+      desc: "optional namespace prefix (alias) that will be used to indicate the namespace_uri when forming a qualified name (i.e., qname) when referencing type definitions from the imported"
+      required: no
+      type: str
+
+#see section 3.5.8
+_property_definition: &property_definition
+  type: map
+  name: property_definition
+  mapping:
+    "type":
+      type: str
+      required: yes
+#not as easy, it can be an user defined data type
+#      <<: *primitive_types
+    description:
+      type: str
+      required: no
+    constraints:
+      desc: "The optional list of sequenced constraint clauses for the Data Type."
+      required: no
+      <<: *constraints_sequence
+    default:
+      type: any
+      required: no
+    "required":
+      type: bool
+      required: no
+    status:
+      type: str
+      required: no
+      <<: *status_values
+    entry_schema:
+      <<: *entry_schema_definition
+#      desc: "used to declare the name of the Datatype definition for entries of set types such as the TOSCA list or map."
+#      type: str
+#      required: no
+
+#see section A.5.8
+#_property_assignment_definition: &property_assignment_definition
+
+#see 3.5.10
+_attribute_definition: &attribute_definition
+  type: map
+  name: attribute_definition
+  mapping:
+    "type":
+      type: str
+      required: yes
+#      <<: *primitive_types
+    description:
+      type: str
+      required: no
+    default:
+      type: any
+      required: no
+    status:
+      desc: "The optional status of the attribute relative to the specification or implementation"
+      type: str
+      required: no
+      <<: *status_values
+    entry_schema:
+      <<: *entry_schema_definition
+#      desc: "Used to declare the name of the Datatype definition for entries of set types such as the TOSCA list or map"
+#      type: str
+#      required: no
+
+#see section 3.5.11
+#here again, we must support the short form which is the most common
+_attribute_assignment_definition: &attribute_assignment_definition
+  type: map
+  name: attribute_assignment_definition
+  mapping:
+    description:
+      desc: "The optional description of the attribute."
+      required: no
+      type: str
+    value:
+#actually 'value | value_expression'
+      desc: "represent the type-compatible value to assign to the named attribute. Attribute values may be provided as the result from the evaluation of an expression or a function"
+      required: yes
+      type: any
+
+
+#see 3.5.12
+_parameter_definition: &parameter_definition
+  type: map
+  name: parameter_definition
+  mapping:
+    "type":
+      type: str
+      required: no
+#not as easy, it can be an user defined data type
+#      <<: *primitive_types
+    description:
+      type: str
+      required: no
+    constraints:
+      desc: "The optional list of sequenced constraint clauses for the Data Type."
+      required: no
+      <<: *constraints_sequence
+    default:
+      type: any
+      required: no
+    "required":
+      type: bool
+      required: no
+    status:
+      type: str
+      required: no
+      <<: *status_values
+    value:
+      desc: "represent the type-compatible value to assign to the named parameter. Parameter values may be provided as the result from the evaluation of an expression or a function"
+      required: yes
+      type: any
+    entry_schema:
+      <<: *entry_schema_definition
+
+
+
+
+# see spec section 3.5.13
+
+# see spec section 3.5.13.2: variant to be used in node or relationship type definitions 
+_type_operation_definition: &type_operation_definition
+  type: map
+  name: type_operation_definition
+  short: implementation
+  mapping:
+    description:
+      desc: "The optional description string for the associated named operation."
+      required: no
+      type: str
+    implementation:
+      desc: "The optional implementation artifact name (e.g., a script file name within a TOSCA CSAR file)"
+      required: no
+      type: str
+    inputs:
+      desc: ""
+      required: no
+      type: map
+      mapping:
+        =:
+          desc: "a property value or an expression providing a input value"
+          name: property_assignment
+          type: any
+
+# from 3.5.13.2.3
+_template_operation_definition: &template_operation_definition
+  type: map
+  name: template_operation_definition
+  short: implementation
+  mapping:
+    description:
+      desc: "The optional description string for the associated named operation."
+      required: no
+      type: str
+    implementation:
+      desc: "The optional implementation artifact name (e.g., a script file name within a TOSCA CSAR file)"
+      name: template_operation_implementation_definition
+      required: no
+      short: primary
+      type: map
+      mapping:
+        primary:
+          desc: "The optional implementation artifact name (e.g., the primary script file name within a TOSCA CSAR file). "
+          required: no
+          type: str
+        dependencies:
+          desc: "The optional list of one or more dependent or secondary implementation artifact name which are referenced by the primary implementation artifact (e.g., a library the script installs or a secondary script)"
+          required: no
+          type: seq
+          sequence: 
+            - type: str
+    inputs:
+      desc: ""
+      required: no
+      type: map
+      mapping:
+        =:
+          desc: "a property value or an expression providing a input value"
+          name: property_assignment
+          type: any
+
+
+# see section 3.5.14, specifically 3.5.14.2.1 : definition to be used in node or relationship type definition
+_type_interface_definition: &type_interface_definition
+  type: map
+  name: type_interface_definition
+  mapping:
+    "type":
+      desc: "represents the required name of the Interface Type for the interface definition"
+      required: yes
+      type: str
+    inputs:
+      desc: "The optional list of input property definitions available to all defined operations"
+      type: map
+      mapping:
+        =:
+          *property_definition
+    =:
+      *type_operation_definition
+
+# see section 3.5.14.2.2, extended notation to be used in node or relationship template definitions
+_template_interface_definition: &template_interface_definition
+  type: map
+  name: template_interface_definition
+  mapping:
+    inputs:
+      desc: "The optional list of input property definitions available to all defined operations"
+      type: map
+      mapping:
+        =:
+          desc: "a property value or an expression providing a property value"
+          name: property_assignment
+          type: any
+    =:
+      *template_operation_definition
+
+# see section 3.5.15
+_event_filter_definition: &event_filter_definition
+  type: map
+  name: event_filter_definition
+  mapping:
+    node:
+      desc: "The required name of the node type or template that contains either the attribute to be monitored or contains the requirement  that references the node that contains the attribute to be monitored"
+      required: yes
+      type: str
+    requirement:
+      desc: "The optional name of the requirement within the filter’s node that can be used to locate a referenced node that contains an attribute to monitor."
+      required: no
+      type: str
+    capability:
+      desc: "The optional name of a capability within the filter’s node or within the node referenced by its requirement that contains the attribute to monitor."
+      required: no
+      type: str
+
+# see section 3.5.16
+# to be revised, based on working version
+_trigger_definition: &trigger_definition
+  type: map
+  name: trigger_definition
+  mapping:
+    description:
+      desc: ""
+      required: no
+      type: str
+    event_type:
+      desc: "The required name of the event type that activates the trigger’s action."
+      required: yes
+      short: type
+      type: map
+      mapping:
+        type:
+          required: yes
+          type: str
+    schedule:
+      desc: ""
+      required: no
+      type: str
+    target_filter:
+      desc: ""
+      required: no
+      <<: *event_filter_definition
+#the section made up of condition/constraint/period/evaluations/method has a mistmatching example in the spec doc ..
+    condition:
+      desc: ""
+      required: no
+      <<: *constraints_sequence
+    constraint:
+      desc: ""
+      required: no
+      <<: *constraints_sequence
+    period:
+      desc: "The optional period to use to evaluate for the condition"
+      required: no
+      type: int
+    evaluations:
+      desc: ""
+      required: no
+      type: int
+    method:
+      desc: "The optional statistical method name to use to perform the evaluation of the condition"
+      required: no
+      type: str
+    action:
+      desc: "The if of the workflow to be invoked when the event is triggered and the condition is met (i.e, evaluates to true) OR the required operation to invoke when the event is triggered and the condition is met (i.e., evaluates to true)."
+      required: yes
+      type: str # or operation definition?
+
+
+# see section 3.5.17
+# to be revised, based on working version
+# example on 3.5.17.4 shows this as a sequence of maps
+# the map must a length/size of 1: none of the entries is required bjut one must be present (mutually exclusive)
+_workflow_activity_definition: &workflow_activity_definition
+  type: map
+  short: call_operation
+  name: workflow_activity_definition
+#  size: 1
+  mapping:
+    delegate:
+      desc: ""
+      required: no
+      type: str
+    set_state:
+      desc: ""
+      required: no
+      type: str
+    call_operation:
+      desc: ""
+      required: no
+      type: str
+    inline:
+      desc: ""
+      required: no
+      type: str
+
+
+# see section 3.5.18
+# to be revised, based on working version
+_workflow_assertion_definition: &workflow_assertion_definition
+  name: workflow_assertion_definition
+  type: map
+  mapping:
+    =:
+      *constraints_sequence
+
+
+# see section 3.5.19
+# to be revised, based on working version
+# it employs a recursive definition which yaml allows but the parsers we've tried complain about, i.e the pattern
+#    foo: &foo
+#      bar: *foo
+# is theoretically allowed in YAML
+# we have enabled recursive defintions in kwalify through reference rules.
+# the spec is 'vague': it assumes a logical 'AND' between the entries of the top sequence of the rule
+_workflow_condition_clause_definition: &workflow_condition_clause_definition
+  name: workflow_condition_clause_definition
+  type: seq
+  sequence: &workflow_condition_clause_entry
+    - type: map
+      name: workflow_condition_clause_entry
+      mapping:
+        assert:
+          type: seq
+          sequence:
+            - *workflow_assertion_definition
+        and:
+          type: ref
+          rule: workflow_condition_clause_definition
+          # recursive definition ! yaml parser cannot deal with it
+          # <<: *workflow_condition_clause_definition
+             
+        or:
+          type: ref
+          rule: workflow_condition_clause_definition 
+          # recursive definition ! yaml parser cannot deal with it
+          # <<: *workflow_condition_clause_definition
+
+# see section 3.5.20
+# to be revised, based on working version
+# here too, not clear if this a map or a sequence .. there is no example
+_workflow_precondition_definition: &workflow_precondition_definition
+  name: workflow_precondition_definition
+  type: map
+  mapping:
+    target:
+      required: yes
+      type: str
+    target_relationship:
+      required: no
+      type: str
+    condition:
+      desc: "list of condition clause definition .. !@#$%"
+      <<: *workflow_condition_clause_definition
+
+
+# see section 3.5.21
+# to be revised, based on working version
+_workflow_step_definition: &workflow_step_definition
+  name: workflow_step_definition
+  desc: "A workflow step allows to define one or multiple sequenced activities in a workflow and how they are connected to other steps in the workflow. They are the building blocks of a declarative workflow."
+  type: map
+  mapping:
+    target:
+      required: yes
+      type: str
+      desc: "The target of the step (this can be a node template name, a group name)"
+    target_relationship:
+      required: no
+      type: str
+    operation_host:
+      required: no
+      type: str
+    filter:
+      desc: "Filter is a map of attribute name, list of constraint clause that allows to provide a filtering logic"
+      type: map
+      mapping:
+        =:
+          *constraints_sequence
+    activities:
+      desc: "The list of sequential activities to be performed in this step"
+      type: seq
+      sequence:
+        - *workflow_activity_definition
+    on_success:
+      desc: "The optional list of step names to be performed after this one has been completed with success (all activities has been correctly processed)."
+      type: seq
+      sequence:
+        - type: str
+    on_failure:
+      desc: "The optional list of step names to be called after this one in case one of the step activity failed."
+      type: seq
+      sequence:
+        - type: str
+
+
+
+
+# 3.6 section: type specific definitions
+
+# see section 3.6.2
+_capability_definition: &capability_definition
+  type: map
+  name: capability_definition
+  short: type
+  mapping:
+    "type":
+      desc: "The required name of the Capability Type the capability definition is based upon"
+      required: yes
+      type: str
+    description:
+      desc: "The optional description of the Capability definition"
+      required: no
+      type: str
+    properties:
+      desc: ""
+      required: no
+      type: map
+      mapping:
+       =:
+          *property_definition
+    attributes:
+      desc: "An optional list of property definitions for the Capability definition"
+      required: no
+      type: map
+      mapping:
+        =:
+          *attribute_definition
+    valid_source_types:
+      desc: ""
+      required: no
+      type: seq
+      sequence:
+        - type: str
+    occurrences:
+      desc: "The optional minimum and maximum occurrences for the capability."
+      required: no
+      <<: *range_definition
+
+
+
+
+# see section 3.6.3
+#
+_requirement_definition: &requirement_definition
+  type: map
+  name: requirement_definition
+  short: capability  #as per A.6.2.2.1
+  mapping:
+    capability:
+      desc: "The required reserved keyname used that can be used to provide the name of a valid Capability Type that can fulfil the requirement"
+      required: yes
+      type: str
+    node:
+      desc: "The optional reserved keyname used to provide the name of a valid Node Type that contains the capability definition that can be used to fulfil the requirement. "
+      required: no
+      type: str
+    relationship:
+# and from section A.6.2.1, this one is an oddball
+      desc: "The optional reserved keyname used to provide the name of a valid Relationship Type to construct when fulfilling the requirement."
+      required: no
+      name: requirement_relationship_definition
+      short: type
+      type: map
+      mapping:
+        type:
+          desc: "The optional reserved keyname used to provide the name of the Relationship Type for the requirement definitions relationship keyname.
+"
+          required: yes
+          type: str
+        interfaces:
+          #not clear which interface definition is to be used here
+          desc: "allows augmentation (additional properties and operations) of the interfaces defined by the relationship type indicated above"
+          required: no
+          type: map
+          mapping:
+            =:
+              *type_interface_definition
+    occurrences:
+      desc: "The optional minimum and maximum occurrences for the requirement."
+      required: no
+      <<: *range_definition
+
+# see section 3.6.4
+_artifact_type_definition: &artifact_type_definition
+  type: map
+  name: artifact_type_definition
+  mapping:
+    derived_from:
+      desc: "An optional parent Artifact Type name the Artifact Type derives from"
+      required: no
+      type: str
+    version:
+      <<: *version_definition
+    metadata:
+      <<: *metadata_definition
+    description:
+      desc: "An optional description for the Artifact Type."
+      required: no
+      type: str
+    mime_type:
+      desc: "The required mime type property for the Artifact Type."
+      required: no
+      type: str
+    file_ext:
+      desc: "The required file extension property for the Artifact Type"
+      required: no
+      type: seq
+      sequence:
+        - type: str
+    properties:
+      desc: "An optional list of property definitions for the Artifact Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          *property_definition
+
+#see spec section #3.6.5
+_interface_type_definition: &interface_type_definition
+  type: map
+  name: interface_type_definition
+  mapping:
+    derived_from:
+      desc: "The name of the Interface Type this Interface Type definition derives from"
+      required: no
+      type: str
+    description:
+      desc: "The optional description for the Interface Type."
+      required: no
+      type: str
+    version:
+      <<: *version_definition
+    metadata:
+      <<: *metadata_definition
+    inputs:
+      desc: "The optional list of input property definitions available to all defined operations"
+      type: map
+      mapping:
+        =:
+          type: str
+          desc: "property_name to property_value(_expression) mapping"
+    =:
+      *type_operation_definition
+
+#see spec section #3.6.6
+_data_type_definition: &data_type_definition
+  type: map
+  name: data_type_definition
+  mapping:
+    derived_from:
+      desc: "The optional key used when a datatype is derived from an existing TOSCA Data Type."
+      required: no
+      type: str
+    description:
+      desc: "The optional description for the Data Type."
+      required: no
+      type: str
+    version:
+      <<: *version_definition
+    metadata:
+      <<: *metadata_definition
+    constraints:
+      desc: "The optional list of sequenced constraint clauses for the Data Type."
+      <<: *constraints_sequence
+    properties:
+      desc: "The optional list property definitions that comprise the schema for a complex Data Type in TOSCA"
+      type: map
+      mapping:
+        =:
+          *property_definition
+
+# see section 3.6.7
+_capability_type_definition: &capability_type_definition
+  type: map
+  name: capability_type_definition
+  mapping:
+    derived_from:
+      desc: "An optional parent capability type name this new Capability Type derives from."
+      required: no
+      type: str
+    version:
+      <<: *version_definition
+    description:
+      desc: "An optional description for the Capability Type"
+      required: no
+      type: str
+    properties:
+      desc: "An optional list of property definitions for the Capability Type."
+      required: no
+      type: map
+      mapping:
+        =:
+          *property_definition
+    attributes:
+      desc: "An optional list of attribute definitions for the Capability Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          *attribute_definition
+    valid_source_types:
+      desc: "An optional list of one or more valid names of Node Types that are supported as valid sources of any relationship established to the declared Capability Type"
+      required: no
+      type: seq
+      sequence:
+        - type: str
+
+# section A.6.7 requirement definition: TOSCA YAML profile relies on capability types to 
+# define requirements 
+
+# see section #3.6.10
+_relationship_type_definition: &relationship_type_definition
+  type: map
+  name: relationship_type_definition
+  mapping:
+    derived_from:
+      desc: "An optional parent Relationship Type name the Relationship Type derives from"
+      required: no
+      type: str
+    description:
+      desc: "An optional description for the Relationship Type."
+      required: no
+      type: str
+    version:
+      <<: *version_definition
+    metadata:
+      <<: *metadata_definition
+    properties:
+      desc: "An optional list of property definitions for the Relationship Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          *property_definition
+    attributes:
+      desc: "An optional list of attribute definitions for the Relationship Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          *attribute_definition
+    interfaces:
+      desc: "An optional list of interface definitions interfaces supported by the Relationship Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          *type_interface_definition
+    valid_target_types:
+      desc: "An optional list of one or more names of Capability Types that are valid targets for this relationship. "
+      required: no
+      type: seq
+      sequence:
+        - type: str
+
+#see section 3.6.11
+_group_type_definition: &group_type_definition
+  type: map
+  name: group_type_definition
+  mapping:
+    derived_from:
+      desc: "An optional parent Group Type name this new Group Type derives from"
+      required: no
+      type: str
+    description:
+      desc: "An optional description for the Group Type"
+      required: no
+      type: str
+    version:
+      <<: *version_definition
+    metadata:
+      <<: *metadata_definition
+    properties:
+      desc: "An optional list of property definitions for the Group Type."
+      required: no
+      type: map
+      mapping:
+        =:
+          *property_definition
+    members:
+      desc: "An optional list of one or more names of Node Types that are valid
+(allowed) as members of the Group Type."
+      required: no
+      type: seq
+      sequence:
+        - type: str
+    interfaces:
+      desc: "An optional list of interface definitions supported by the Group Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          *type_interface_definition
+    requirements:
+      desc: "An optional sequenced list of requirement definitions for the Group Type."
+      required: no
+      type: seq
+      sequence:
+        - type: map
+          mapping:
+            =:
+              *requirement_definition
+    capabilities:
+      desc: "An optional list of capability definitions for the Group Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          *capability_definition
+
+
+
+#see section 3.6.12
+_policy_type_definition: &policy_type_definition
+  type: map
+  name: policy_type_definition
+  mapping:
+    derived_from:
+      desc: "An optional parent Policy Type name this new Policy Type derives from"
+      required: no
+      type: str
+    description:
+      desc: "An optional description for the Policy Type"
+      required: no
+      type: str
+    version:
+      <<: *version_definition
+    metadata:
+      <<: *metadata_definition
+    properties:
+      desc: "An optional list of property definitions for the Policy Type."
+      required: no
+      type: map
+      mapping:
+        =:
+          *property_definition
+    targets:
+      desc: "An optional list of valid Node Types or Group Types the Policy Type
+can be applied to"
+      required: no
+      type: seq
+      sequence:
+        - type: str
+    triggers:
+      desc: "List of trigger defintions"
+      required: no
+      type: seq
+      sequence:
+        - *trigger_definition
+
+
+# see section #3.6.9
+_node_type_definition: &node_type_definition
+  type: map
+  name: node_type_definition
+  mapping:
+    derived_from:
+      desc: "An optional parent Node Type name this new Node Type derives from"
+      required: no
+      type: str
+    description:
+      desc: "An optional description for the Node Type"
+      required: no
+      type: str
+    version:
+      <<: *version_definition
+    metadata:
+      <<: *metadata_definition
+    properties:
+      desc: "An optional list of property definitions for the Node Type."
+      required: no
+      type: map
+      mapping:
+        =:
+          *property_definition
+    attributes:
+      desc: "An optional list of attribute definitions for the Node Type.
+"
+      required: no
+      type: map
+      mapping:
+        =:
+          *attribute_definition
+    requirements:
+      desc: "An optional sequenced list of requirement definitions for the Node Type.
+"
+      required: no
+      type: seq
+      sequence:
+        - type: map
+          mapping:
+            =:
+              *requirement_definition
+    capabilities:
+      desc: "An optional list of capability definitions for the Node Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          *capability_definition
+    interfaces:
+      desc: ""
+      required: no
+      type: map
+      mapping:
+        =:
+          *type_interface_definition
+    artifacts:
+      desc: "An optional list of named artifact definitions for the Node Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          *artifact_definition
+
+# 3.7 Template specific definitions
+
+# see section 3.7.1
+_capability_assignment_definition: &capability_assignment_definition
+  type: map
+  name: capability_assignment_definition
+  mapping:
+    properties:
+      # list of property assignments
+      desc: "An optional list of property definitions for the Capability definition"
+      required: no
+      type: map
+      mapping:
+        =:
+          desc: "a property value or an expression providing a property value"
+          name: property_assignment
+          type: any
+    attributes:
+      # list of attribute assignments
+      desc: "An optional list of attribute definitions for the Capability definition"
+      required: no
+      type: map
+      mapping:
+        =:
+          desc: ""
+          name: attribute_assignment
+          type: any
+
+# see section 3.7.2
+_requirement_assignment_definition: &requirement_assignment_definition
+  type: map
+  name: requirement_assignment_definition
+  short: node
+  mapping:
+    capability:
+      desc: " used to provide the name of either a: Capability definition within a target node template that can fulfill the requirement or Capability Type that the provider will use to select a type-compatible target node template to fulfill the requirement at runtime."
+      required: no
+      type: str
+    node:
+#why is this a reference to a node type and not to a node template??
+      desc: "used to identify the target node of a relationship: Node Template name that can fulfil the target node requirement or Node Type name that the provider will use to select a type-compatible node template to fulfil the requirement at runtime"
+      required: no
+      type: str
+    relationship:
+      desc: ""
+      required: no
+#fins a better name      name: relationship_definition
+      type: map
+      short: type
+      mapping:
+        "type":
+          desc: "The optional reserved keyname used to provide the name of the Relationship Type for the requirement assignments relationship keyname"
+          required: no
+          type: str
+        properties:
+          desc: ""
+          required: no
+          type: map
+          mapping:
+            =:
+              desc: "a property value or an expression providing a property value"
+              name: property_assignment
+              type: any
+        interfaces:
+          desc: "from A.5.12.2.2, right?"
+          required: no
+          type: map
+          mapping:
+            =:
+              *template_interface_definition
+    node_filter:
+      desc: "The optional filter definition that TOSCA orchestrators or providers would use to select a type-compatible target node that can fulfill the associated abstract requirement at runtime."
+      required: no
+      <<: *node_filter_definition
+
+# see section 3.7.3
+_node_template_definition: &node_template_definition
+  type: map
+  name: node_template_definition
+  mapping:
+    "type":
+      desc: "The required name of the Node Type the Node Template is based upon"
+      required: yes
+      type: str
+    description:
+      desc: "An optional description for the Node Template"
+      required: no
+      type: str
+    metadata:
+      <<: *metadata_definition
+    directives:
+      desc: "An optional list of directive values to provide processing instructions to orchestrators and tooling."
+      required: no
+      type: seq
+      sequence:
+        - type: str
+    properties:
+#custom check needs to be added: the value or expression providing the property value
+#needs to be compatible with the property definition
+      desc: "An optional list of property value assignments for the Node Template."
+      required: no
+      type: map
+      mapping:
+        =:
+          type: any
+          name: property_assignment
+          desc: "a property value or an expression providing a property value"
+    attributes:
+      desc: "An optional list of attribute value assignments for the Node Template"
+      required: no
+      type: map
+      mapping:
+        =:
+          *attribute_assignment_definition
+    requirements:
+      desc: "An optional sequenced list of requirement assignments for the Node Template."
+      required: no
+      type: seq
+      sequence:
+        - type: map
+          mapping:
+            =:
+              *requirement_assignment_definition
+    capabilities:
+      desc: "An optional list of capability assignments for the Node Template."
+      required: no
+      type: map
+      mapping:
+        =:
+          *capability_assignment_definition
+    interfaces:
+      desc: "An optional list of named interface definitions for the Node Template"
+      required: no
+      type: map
+      mapping:
+        =:
+          *template_interface_definition
+    artifacts:
+      desc: "An optional list of named artifact definitions for the Node Template.
+"
+      required: no
+      type: map
+      mapping:
+        =:
+          *artifact_definition
+    node_filter:
+      desc: "The optional filter definition that TOSCA orchestrators would use to select the correct target node. This keyname is only valid if the directive has the value of 'selectable' set."
+      required: no
+      <<: *node_filter_definition 
+    copy:
+      desc: "The optional (symbolic) name of another node template to copy into (all keynames and values) and use as a basis for this node template."
+      required: no
+      type: str
+
+# see section 3.7.4
+_relationship_template_definition: &relationship_template_definition
+  type: map
+  name: relationship_template_definition
+  mapping:
+    "type":
+      desc: "The required name of the Relationship Type the Relationship Template is based upon"
+      required: yes
+      type: str
+    description:
+      desc: "An optional description for the Relationship Template"
+      required: no
+      type: str
+    metadata:
+      <<: *metadata_definition
+    properties:
+      desc: "An optional list of property assignments for the Relationship Template."
+      required: no
+      name: properties_assignment_validation
+      type: map
+      mapping:
+        =:
+          type: any
+#scalar
+          desc: "an expression providing a property value"
+    attributes:
+      desc: "An optional list of attribute value assignments for the Relationship Template"
+      required: no
+      name: attributes_assignment_validation
+      type: map
+      mapping:
+        =: 
+          type: scalar
+          desc: "an expression providing an attribute value"
+    interfaces:
+      desc: "An optional list of named interface definitions for the Relationship Template ('augmentation' is allowed here)"
+      required: no
+      type: map
+      mapping:
+        =:
+          *template_interface_definition
+    copy:
+      desc: "The optional (symbolic) name of another relationship template to copy into (all keynames and values) and use as a basis for this relationship template."
+      required: no
+      type: str
+
+
+# see section 3.7.5
+_group_definition: &group_definition
+  type: map
+  name: group_definition
+  mapping:
+    "type":
+      desc: "The required name of the group type the group definition is based upon"
+      required: yes
+      type: str
+    description:
+      desc: "The optional description for the group definition"
+      required: no
+    metadata:
+      <<: *metadata_definition
+    properties:
+      desc: " represents the optional list of property assignments for the group definition that provide values for properties defined in its declared Group Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          type: any
+          name: property_assignment
+    members:
+      desc: "contains the required list of one or more node template names (within the same topology template) that are members of this logical group"
+      required: yes
+      type: seq
+      sequence:
+        - type: str
+    interfaces:
+      desc: "represents the optional list of interface definitions for the group definition that augment those provided by its declared Group Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          *template_interface_definition
+
+# see section 3.7.6
+_policy_template_definition: &policy_template_definition
+  type: map
+  name: policy_definition
+  mapping:
+    "type":
+      desc: "The required name of the policy type the policy definition is based upon"
+      required: yes
+      type: str
+    description:
+      desc: "The optional description for the policy definition"
+      required: no
+    metadata:
+      <<: *metadata_definition
+    properties:
+      desc: "represents the optional list of property assignments for the policy definition that provide values for properties defined in its declared Policy Type"
+      required: no
+      type: map
+      mapping:
+        =:
+          type: any
+          name: property_assignment
+    targets:
+      desc: "represents the optional list of names of node templates or groups that the policy is to applied to"
+      required: no
+      type: seq
+      sequence:
+        - type: str
+    triggers:
+      desc: "List of trigger definitions"
+      required: no
+      type: seq
+      sequence:
+        - *trigger_definition
+
+#see section 3.7.7, obviously incomplete spec
+_workflow_definition: &workflow_definition
+  type: map
+  name: workflow_definition
+  mapping:
+    description:
+      desc: "The optional description for the workflow definition"
+      required: no
+    metadata:
+      <<: *metadata_definition
+    inputs:
+      desc: "optional list of input parameter definitions"
+      required: no
+      type: map
+      mapping:
+        =:
+          *property_definition
+    preconditions:
+      desc: "List of preconditions to be validated before the workflow can be processed."
+      required: no
+      type: seq
+      sequence:
+         - *workflow_precondition_definition
+    steps:
+      desc: ""
+      required: no
+      type: map
+      mapping:
+        =:
+          *workflow_step_definition
+
+
+# see section 3.8 Topology Template definition:  defines the topology template of a cloud application.
+# described as a a reusable grammar as it can be a part of a service template definition 
+_topology_template_definition: &topology_template_definition
+  type: map
+  name: topology_template_definition
+  mapping:
+    description:
+      desc: "a description of the topology template"
+      required: no
+      type: str
+    inputs:
+      desc: "definition of input parameters for the topology template"
+      name: inputs
+      required: no
+      type: map
+      mapping:
+        =:
+          *property_definition
+    node_templates:
+      desc: "definition of the node templates of the topology"
+      name: node_templates
+      required: no
+      type: map
+      mapping:
+        =:
+          *node_template_definition
+    relationship_templates:
+      desc: "definition of the relationship templates of the topology"
+      required: no
+      name: relationship_templates
+      type: map
+      mapping:
+        =:
+          *relationship_template_definition
+    outputs:
+      desc: "definition of output parameters for the topology template"
+      name: outputs
+      required: no
+      type: map
+      mapping:
+        =:
+          *attribute_assignment_definition
+    groups:
+      desc: "An optional list of Group definitions whose members are node templates defined within this same Topology Template"
+      name: groups
+      required: no
+      type: map
+      mapping:
+        =:
+          *group_definition
+    policies:
+ # see 8.2.3, initially the list is not described as sequenced but then the grammar shows it as such !?
+      desc: "An optional sequenced?? list of Policy definitions for the Topology Template."
+      name: policies
+      required: no
+      type: seq
+      sequence:
+        - type: map
+          mapping:
+            =:
+              *policy_template_definition
+    workflows:
+      desc: "optional map of imperative workflow definition for the Topology Template"
+      name: workflows
+      required: no
+      type: map
+      mapping:
+        =:
+          *workflow_definition
+    substitution_mappings:
+# one possible short-coming that is visible here is that the definition of the capability
+# and requirements mappings are given in the spec only with the short/inline version of a 
+# YAML list/sequence, which cannot be enforced here .. 
+      desc: " a description of the topology template"
+      name: substitution_mappings
+      required: no
+      type: map
+      mapping:
+        node_type:
+          desc: "node type name"
+          required: yes
+          type: str
+        capabilities:
+          desc: "map_of_capability_mappings_to_expose"
+          type: map
+          mapping:
+            =:
+              type: seq
+              sequence:
+                - type: str
+        requirements:      
+          desc: "map_of_requirement_mapping_to_expose"
+          type: map
+          mapping:
+            =:
+              type: seq
+              sequence:
+                - type: str
+
+
+# see A.9 Service Template definition: A TOSCA Service Template (YAML) document contains
+# element definitions of building blocks for cloud application, or complete models of cloud applications. 
+
+type: map
+name: service_template_definition
+mapping:
+  tosca_definitions_version:
+    desc: "Required TOSCA Definitions version string"
+    required: yes
+    type: str
+    enum: [tosca_simple_yaml_1_1, tosca_simple_yaml_1_1_0]
+
+  tosca_default_namespace:
+    desc: "Optional. default namespace (for type schema)"
+    required: no
+    type: str
+
+  metadata:
+    desc: "Optional metadata keyname: value pairs"
+    name: metadata
+    required: no
+    type: map
+    mapping:
+      template_name:
+        desc: "Optional name of this service template"
+        required: no
+        type: str
+      template_author:
+        desc: "Optional author of this service template"
+        required: no
+        type: str
+      template_version:
+        desc: "Optional version of this service template"
+        required: no
+        type: str
+      =:
+        desc: "User defined entry"
+        required: no
+        type: str
+
+#to add, the spec says: "Optional list of domain or profile specific metadata keynames"
+
+  description:
+    desc: "Optional description of the definitions inside the file"
+    required: no
+    type: str
+
+  imports:
+    desc: "ordered list of import statements for importing other definitions files"
+    name: imports
+    required: no
+    type: seq
+    sequence:
+      - type: map
+        mapping:
+          =:
+            *import_definition
+
+  dsl_definitions:
+    desc: "list of YAML alias anchors (or macros)"
+    name: dsl_definitions
+    required: no
+    type: map
+    mapping:
+      =:
+        desc: "some piece of valid yaml that makes the anchor/alias definition" 
+        type: any
+        required: no
+
+  repositories:
+    desc: "list of external repository definitions which host TOSCA artifacts"
+    name: repositories
+    required: no
+    type: map
+    mapping:
+      =:
+        *repository_definition
+
+  data_types:
+    desc: "list of TOSCA datatype definitions"
+    name: data_types
+    required: no
+    type: map
+    mapping:
+      =:
+        *data_type_definition
+
+  node_types:
+    desc: "list of node type definitions"
+    name: node_types
+    required: no
+    type: map
+    mapping:
+      =:
+        *node_type_definition
+
+  capability_types:
+    desc: "list of capability type definitions"
+    name: capability_types
+    required: no
+    type: map
+    mapping:
+      =:
+        *capability_type_definition
+
+  relationship_types:
+    desc: "list of relationship type definitions"
+    name: relationship_types
+    required: no
+    type: map
+    mapping:
+      =:
+        *relationship_type_definition
+
+  artifact_types:
+    desc: "list of artifact type definitions"
+    name: artifact_types
+    required: no
+    type: map
+    mapping:
+      =:
+        *artifact_type_definition
+
+  interface_types:
+    desc: "list of interface type definitions"
+    name: interface_types
+    required: no
+    type: map
+    mapping:
+      =:
+        *interface_type_definition
+
+  group_types:
+    desc: "list of group type definitions"
+    name: group_types
+    required: no
+    type: map
+    mapping:
+      =:
+        *group_type_definition
+
+  policy_types:
+    desc: "list of policy type definitions"
+    name: policy_types
+    required: no
+    type: map
+    mapping:
+      =:
+        *policy_type_definition
+
+  topology_template:
+    desc: "topology template definition of the cloud application or service"
+    required: no
+    <<: *topology_template_definition
diff --git a/javatoscachecker/checker/src/test/java/org/onap/tosca/checker/test/CSAR.java b/javatoscachecker/checker/src/test/java/org/onap/tosca/checker/test/CSAR.java
new file mode 100644
index 0000000..aeeef20
--- /dev/null
+++ b/javatoscachecker/checker/src/test/java/org/onap/tosca/checker/test/CSAR.java
@@ -0,0 +1,35 @@
+package org.onap.tosca.checker.test;
+
+import java.net.URI;
+
+import org.onap.tosca.checker.Checker;
+import org.onap.tosca.checker.Target;
+import org.onap.tosca.checker.Catalog;
+import org.onap.tosca.checker.CSARRepository;
+
+public class CSAR {
+
+  public static void main(String[] theArgs) {
+
+    if (theArgs.length == 0) {
+      System.err.println("You need to specify a CSAR archive to process");
+      return;
+    }
+
+		try {
+			CSARRepository repo = new CSARRepository(theArgs[0], new URI(theArgs[0]));
+			Checker checker = new Checker();
+			checker.setTargetLocator(repo.getTargetLocator());
+			checker.check(repo.mainTarget());
+			
+			Catalog cat = checker.catalog();
+			for (Target t: cat.targets()) {
+				System.err.println(t.getLocation() + "\n" + cat.importString(t) + "\n" + t.getReport());
+			}
+		}
+		catch (Exception x) {
+			x.printStackTrace();
+		}
+  }
+
+}
diff --git a/javatoscachecker/checker/src/test/tosca/dcae_uservice_tosca.yaml b/javatoscachecker/checker/src/test/tosca/dcae_uservice_tosca.yaml
new file mode 100644
index 0000000..2c5c028
--- /dev/null
+++ b/javatoscachecker/checker/src/test/tosca/dcae_uservice_tosca.yaml
@@ -0,0 +1,653 @@
+#   First attempt at microservice definitions in tosca-yaml.
+#   Ted Johnson, Dec. 2015
+##  Ralph Knag,  config additions , Feb. 2016
+
+tosca_definitions_version: tosca_simple_yaml_1_0_0
+
+metadata:
+    template_version: 1.0.2
+
+
+data_types:
+########################################################
+###     data types related to schemas
+
+    baseFieldDefinition:
+        description: base class for field definitions
+        properties:
+            name:
+                required: true
+                type: string
+            type:
+                required: true
+                type: string
+                constraints:
+                    - valid_values: [ string, int, float, ipv4, ipv6, date, date_time, list, map, other]
+            format:
+                required: false
+                type: string
+            default_value:
+                required: false
+                type: string
+            comment:
+                required: false
+                type: string
+            constraints:
+                description: Properties that the field must satisfy
+                required: false
+                type: list
+                entry_schema:
+                    type: string
+                    constraints:
+            list_delimiter:
+                description: delimiter when list data packed into a string type.
+                required: false
+                type: string
+# subtype can be used for policy override allowed?
+            subType:
+                required: false
+                type : string
+                constraints:
+                    - valid_values: [ policyOveride, noPolicyOverride ]
+
+    positionalFieldDefinition:
+        derived_from: baseFieldDefinition
+        description: fields with a fixed-position schema
+        properties:
+            position:
+                required: true
+                type: integer
+                constraints: 
+                    - greater_or_equal: 0
+                    
+    pathFieldDefinition:
+        derived_from: baseFieldDefinition
+        description: fields accessed via navigation
+        properties:
+            path:
+                required: true
+                type: string
+
+    fieldDefinition:
+        derived_from: baseFieldDefinition
+        description: positional or path field
+        properties:
+            path:
+                required: false
+                type: string
+            position:
+                required: false
+                type: integer
+                constraints: 
+                    - greater_or_equal: 0
+            comment:
+                required: false
+                type: string
+            length:
+                required: false
+                type: integer
+                constraints:
+                    - greater_than: 0
+
+    fieldList:
+        description: fields in a schema
+        properties:
+            fieldList:
+                required: true
+                type: list
+                entry_schema:
+                    type: fieldDefinition
+
+
+                    
+########################################################
+###     data types related to data properties
+
+    sortedBy:
+        description: sorting properties of a data set
+        properties:
+            fields:
+                required: true
+                type: list
+                entry_schema:
+                    type: fieldDefinition
+            sorting:
+                required: true
+                type: string
+                default: fullySorted
+                constraints:
+                    - valid_values: [ fullySorted, partiallySorted ]
+            lag:
+                description: maximum disorder in a partially sorted
+                required: false
+                type: integer
+                constraints:
+                    - greater_or_equal: 0
+
+    keyFields:
+        description: key fields of a data set
+        properties:
+            fields:
+                required: true
+                type: list
+                entry_schema:
+                    type: fieldDefinition
+            timestamp:
+                required: false
+                type: integer
+
+###############################################################
+###############################################################             
+                
+node_types:
+
+    dcaeCatalogNodes:
+        derived_from: tosca.nodes.Root                
+        properties:
+            UUID:
+                required: true
+                type: string
+            name:
+                required: true
+                type: string
+            version:
+                required: true
+                type: string
+                constraints:
+                  - pattern: \d+[.]\d+[.]\d+
+            schemaVersion:
+                required: false
+                type: integer
+                default: 1
+    
+
+########################################################
+###     node types related to schemas
+                
+
+    baseDataFormat:
+        description: base data format
+        derived_from: dcaeCatalogNodes
+        properties:
+            fieldList:
+                required: true
+                type: list
+                entry_schema:
+                    type: fieldDefinition
+            formatType:
+                type: string
+                required: true
+                constraints:
+                    - valid_values: [ fixed_format, variable_format, json ]
+            formatSubType:
+                required: true
+                type: string
+            fullList:
+                type: string
+                required: true
+                constraints:
+                    - valid_values: [ yes, no ]
+                default: yes
+        capabilities:
+            dataProperties:
+                type: dcaeCatalog.capabilities.dataFormat
+
+    baseVariableDataFormat:
+        derived_from: baseDataFormat
+        description: base class for fixed-position data formats
+        properties:
+            formatType:
+                type: string
+                required: true
+                constraints:
+                    - equal: variable_format
+
+
+# probably more needed here - not sure baseDataFormat is sufficient...rhk
+    jsonDataFormat:
+        derived_from: baseVariableDataFormat
+        description: JSON format
+        properties:
+            formatSubType:
+                required: true
+                type: string
+                default: json
+                constraints:
+                    - equal: json
+            endOfRecord:
+                required: false
+                type: string
+            numFields:
+                required: false
+                type: integer
+
+    baseFixedDataFormat:
+        derived_from: baseDataFormat
+        description: base class for fixed-position data formats
+        properties:
+            formatType:
+                type: string
+                required: true
+                constraints:
+                    - equal: fixed_format
+
+    delimitedAsciiDataFormat:
+        derived_from: baseFixedDataFormat
+        description: delimited ascii format
+        properties:
+            formatSubType:
+                required: true
+                type: string
+                default: delimitedAscii
+                constraints:
+                    - equal: delimitedAscii
+            delimiter:
+                required: true
+                type: string
+                default: |
+            endOfRecord:
+                required: false
+                type: string
+            numFields:
+                required: false
+                type: integer
+
+    fixedWidthAsciiDataFormat:
+        derived_from: baseFixedDataFormat
+        description: delimited ascii format
+        properties:
+            formatSubType:
+                required: true
+                type: string
+                default: fixedWidthAscii
+                constraints:
+                    - equal: fixedWidthAscii
+            endOfRecord:
+                required: false
+                type: string
+            numFields:
+                required: false
+                type: integer
+
+    fixedBinaryDataFormat:
+        derived_from: baseFixedDataFormat
+        description: binary data, e.g. thrift messages, protocol buffers
+        properties:
+            formatSubType:
+                required: true
+                type: string
+                default: fixedBinaryData
+                constraints:
+                    - equal: fixedBinaryData
+            binaryFormat:
+                required: true
+                type: string
+                
+                    
+###############################################
+###     Node types related to data properties
+                    
+    dataProperties:
+        description: Essential non-schema information about a data set
+        derived_from: dcaeCatalogNodes
+        properties:
+            sort:
+                required: false
+                type: sortedBy
+            keys:
+                required: false
+                type: keyFields
+            timestamp:
+                description: the field indicating the time when corresponding event occurred
+                required: false
+                type: string
+            duration:
+                description: the field indicating the length of the described measurement
+                required: false
+                type: string
+            period:
+                description: how often the data is generated.  0 means continuously.
+                required: true
+                type: integer
+                default: 0
+                constraints:
+                    - greater_or_equal: 0
+        capabilities:
+            dataProperties:
+                type: dcaeCatalog.capabilities.dataProperties
+ 
+ 
+    keyedDataProperties:
+        derived_from: dataProperties
+        description: Data sets that are required to hav a key
+        properties:
+            keys:
+                required: true
+                type: keyFields
+
+    referenceDataProperties:
+        derived_from: dataProperties
+        description: data set from external source that is joined against streaming data
+        properties:
+            updateType:
+                description: how the reference data is refreshed - snapshots, incremental, or both
+                required: true
+                type: string
+    
+    keyedReferenceDataProperties:
+        derived_from: referenceDataProperties
+        description: reference data that maps a key to a value, generally with a valid time interval
+        properties:
+            keys:
+                required: true
+                type: keyFields
+            startTimeField:
+                description: the time when the key --> value mapping became valid
+                required: false
+                type: string
+            endTimeField:
+                description: time when the key --> value mapping ceased to be valid
+                required: false
+                type: string
+
+                
+#######################################################################
+####    Things which describe how a data source can be accessed
+
+
+
+    dataDelivery:
+        description: the means of connecting to a data source.  very incomplete.
+        derived_from: dcaeCatalogNodes
+        properties:
+            deliveryMechanism:
+                description: the general method by which data is delivered from a source.
+                required: true
+                type: string
+                constraints:
+                    - valid_values: [stream, file, database, table ]
+            polling:
+                description: push vs. pull
+                required: true
+                type: string
+                constraints:
+                    - valid_values: [ push, pull]
+        capabilities:
+            dataDelivery:
+                type: dcaeCatalog.capabilities.dataDelivery
+
+    streamDataDelivery:
+        description: a data source that is a streaming source.
+        derived_from: dataDelivery
+        properties:
+            deliveryMechanism:
+                description: the general method by which data is delivered from a source.
+                required: true
+                type: string
+                constraints:
+                    - equal: stream
+            polling:
+                description: push vs. pull
+                required: true
+                type: string
+                constraints:
+                    - equal:  push
+
+
+    genericCDAPDelivery:
+        description: a streaming data source delivered via the CDAP generic 
+        derived_from: streamDataDelivery
+                    
+
+    
+#   A UEB stream is kafka plus security TBD 
+    dmaapMessageDelivery:
+        description: a streaming data source delivered via a kafka queue
+        derived_from: streamDataDelivery
+        properties:
+            servers:
+                description: the servers to contact to access the kafka queue.
+                required: true
+                type: list
+                entry_schema:
+                    type: string
+                    constraints:
+            topic:
+                description: the stream identifier (topic in kafka terminology)
+                required: true
+                type: string
+            numPartitions:
+                description: the number of partitions for the kafka topic
+                required: false
+                default: 1
+                type: integer
+            PartitioningMethod:
+                description: the mechanism that assigns records to partitions
+                required: false
+                type: string
+            partitionSubscriptions:
+                description: if specified, the set of partitions that contain a particular substream
+                required: false
+                type: list
+                entry_schema:
+                    type: integer
+                    
+
+    dmaapDataRouterDelivery:
+        description: a data source that is delivered via files.
+        derived_from: dataDelivery
+        properties:
+            deliveryMechanism:
+                description: the general method by which data is delivered from a source.
+                required: true
+                type: string
+                constraints:
+                    - valid_values: [file]
+            fileName:
+                description: a name (or naming scheme) of the file
+                required: true
+                type: string
+
+    fileDataDelivery:
+        description: a data source that is delivered via files.
+        derived_from: dataDelivery
+        properties:
+            deliveryMechanism:
+                description: the general method by which data is delivered from a source.
+                required: true
+                type: string
+                constraints:
+                    - valid_values: [file]
+            fileName:
+                description: a name (or naming scheme) of the file
+                required: true
+                type: string
+
+    pulledFileDelivery:
+        description: a data source that is delivered via files pulled from an external source
+        derived_from: fileDataDelivery
+        properties:
+            uri:
+                description: the thing to access to get a new file
+                required: true
+                type: string
+            trigger:
+                description: a description of the thing that triggers pulling a new file.
+                required: true
+                type: string
+
+                
+
+####################################
+###     Description of a data source (data output)
+
+    dataSource:
+        description: a generic data source description, link to schema, properties, delivery
+        derived_from: dcaeCatalogNodes
+#        properties:
+        requirements:
+            - dataFormat:
+                capability: dcaeCatalog.capabilities.dataFormat
+            - dataDelivery:
+                capability: dcaeCatalog.capabilities.dataDelivery
+            - dataProperties:
+                capability: dcaeCatalog.capabilities.dataProperties
+        capabilities:
+            dataSource:
+                type: dcaeCatalog.capabilities.dataSource
+                occurrences: [0, UNBOUNDED]
+               
+##########################
+###  Description of a data requirement (data input)
+    dataRequirement:
+        description: a generic data source description, link to schema, properties, delivery
+        derived_from: dcaeCatalogNodes
+#        properties:
+        requirements:
+            - dataFormat:
+                capability: dcaeCatalog.capabilities.dataFormat
+                occurrences: [1, UNBOUNDED]
+            - dataProperties:
+                capability: dcaeCatalog.capabilities.dataProperties
+            - dataDelivery:
+                capability: dcaeCatalog.capabilities.dataDelivery
+        capabilities:
+            dataRequirement:
+                type: dcaeCatalog.capabilities.dataRequirement
+                occurrences: [0, UNBOUNDED]
+        
+  
+                
+
+
+####################################
+###     Description of a processingModuleParameters (module parameters excluding input/output descriptions
+###     allows any baseDataFormat derived input 
+    processingModuleParameters:
+        description:
+        derived_from: baseDataFormat
+        properties:
+            dataType:
+                required: true
+                type: string
+        capabilities:
+            moduleParameters:
+                type: dcaeCatalog.capabilities.processingModuleParameters
+                
+
+################################
+### Module Dependencies
+
+    instantiationDependency:
+        description: code dependencies (possible transitive)
+        derived_from: dcaeCatalogNodes
+        properties:
+            dependencyType:
+                required: false
+                type: string
+                constraints:
+                    - valid_values: [R, Python, CDAP]
+            dependencyValue:
+                required: true
+                type: string
+        capabilities:
+            dataProperties:
+                type: dcaeCatalog.capabilities.instantiationDependency
+                occurrences: [0, UNBOUNDED]
+        requirements:
+            - dependencies:
+                capability: dcaeCatalog.capabilities.instantiationDependency
+                occurrences: [0, UNBOUNDED]
+
+####################################
+###     Description of a processingModuleDeployment - deployment attributes
+
+    processingModuleDeployment:
+        description: deployment attributes
+        derived_from: dcaeCatalogNodes
+        properties:
+            language:
+                required: true
+                type: string
+            version: 
+                type: string
+                required: true
+            deploymentType:
+                required: true
+                type: string
+        capabilities:
+            moduleDeployment:
+                type: dcaeCatalog.capabilities.processingModuleDeployment
+                occurrences: [0, UNBOUNDED]
+        requirements:
+            - dependencies:
+                capability: dcaeCatalog.capabilities.instantiationDependency
+                occurrences: [0, UNBOUNDED]
+
+####################################
+###     Description of a processingModuleMetaData - search tags
+
+    processingModuleMetadata:
+        description: metadata tags
+        derived_from: dcaeCatalogNodes
+        properties:
+            metaDataList:
+                required: true
+                type: list
+                entry_schema:
+                    type: string
+                    constraints:
+        capabilities:
+            metadata:
+                type: dcaeCatalog.capabilities.processingModuleMetadata
+                occurrences: [0, UNBOUNDED]
+        
+
+####################################
+###     Description of a processingModule 
+
+    processingModule:
+        description: full processing module description 
+        derived_from: dcaeCatalogNodes
+        properties:
+            moduleDescription:
+                required: true
+                type: string
+        requirements:
+            - processingModuleparameters:
+                capability: dcaeCatalog.capabilities.processingModuleParameters
+                occurrences: [0, UNBOUNDED]
+            - processingModuleDeployment:
+                capability: dcaeCatalog.capabilities.processingModuleDeployment
+                occurrences: [1, UNBOUNDED]
+            - processingModuleMetadata:
+                capability: dcaeCatalog.capabilities.processingModuleMetadata
+                occurrences: [1, UNBOUNDED]
+            - dataRequirementsList:
+                capability: dcaeCatalog.capabilities.dataRequirement
+                occurrences: [1, UNBOUNDED]
+            - dataSourcesList:
+                capability: dcaeCatalog.capabilities.dataSource
+                occurrences: [1, UNBOUNDED]
+
+capability_types:
+    dcaeCatalog.capabilities.dataFormat: 
+        derived_from: tosca.capabilities.Root 
+    dcaeCatalog.capabilities.dataProperties: 
+        derived_from: tosca.capabilities.Root 
+    dcaeCatalog.capabilities.dataDelivery: 
+        derived_from: tosca.capabilities.Root 
+    dcaeCatalog.capabilities.instantiationDependency:
+        derived_from: tosca.capabilities.Root 
+    dcaeCatalog.capabilities.processingModuleMetadata:
+        derived_from: tosca.capabilities.Root 
+    dcaeCatalog.capabilities.processingModuleParameters:
+        derived_from: tosca.capabilities.Root 
+    dcaeCatalog.capabilities.processingModuleDeployment:
+        derived_from: tosca.capabilities.Root 
+    dcaeCatalog.capabilities.dataRequirement:
+        derived_from: tosca.capabilities.Root 
+    dcaeCatalog.capabilities.dataSource:
+        derived_from: tosca.capabilities.Root 
+    
+    
diff --git a/javatoscachecker/checker/src/test/tosca/mini_ceil_tosca.yaml b/javatoscachecker/checker/src/test/tosca/mini_ceil_tosca.yaml
new file mode 100644
index 0000000..9879746
--- /dev/null
+++ b/javatoscachecker/checker/src/test/tosca/mini_ceil_tosca.yaml
@@ -0,0 +1,108 @@
+tosca_definitions_version: tosca_simple_yaml_1_0_0
+
+imports:
+  - dcae_uservice_tosca.yaml
+
+topology_template:
+
+  node_templates:
+
+    HostComputeStats_Ceilometer:
+      type: delimitedAsciiDataFormat
+      properties:
+          name: HostComputeStats_Ceilometer
+          UUID: HostComputeStats_Ceilometer
+          version: 1.0.0
+          delimiter: "|"
+          fieldList:
+            -
+                name: DATETIME_FTP_COLLECTION
+                type: date_time
+#                subType: 1.0
+                subType: "yyyymmddhhmmss"
+            -
+                name: DATETIME_OSS
+                type: date_time
+                subType: "yyyymmddhhmmss"
+            -
+                name: DATETIMEUTC
+                type: date_time
+                subType: "yyyymmddhhmmss"
+            -
+                name: DATETIMEZONE
+                type: date_time
+                subType: "yyyymmddhhmmss zzz"
+            -
+                name: EMS_NAME
+                type: string
+                comment: "Element Manager System Name?"
+            -
+                name: NE_VERSION
+                type: string
+                comment: "Network Element Version????"
+            -
+                name: PERIOD
+                type: int
+                comment: "Sample period in seconds"
+            -
+                name: SUSPECTFLAG
+                type: string
+                comment: "Data suspect?  Null means ok?"
+            -
+                name: SERVICE
+                type: string
+            -
+                name: resourceid
+                type: string
+            -
+                name: hardware.cpu.load.1min
+                type: float
+                comment: "CPU load in in the last one minute" 
+            -
+                name: hardware.cpu.load.5min
+                type: float
+                comment: "CPU load in in the last five minutes" 
+            -
+                name: hardware.cpu.load.15min
+                type: float
+                comment: "CPU load in in the last fifteen minutes" 
+            -
+                name: hardware.cpu.memory.total
+                type: float
+                comment: "Total memory size in KB"
+            -
+                name: hardware.cpu.memory.avail
+                type: float
+                comment: "Memory available in KB"
+            -
+                name: hardware.cpu.swap.total
+                type: float
+                comment: "Total swap size in KB"
+            -
+                name: hardware.cpu.swap.avail
+                type: float
+                comment: "Swap available in KB"
+            -
+                name: hardware.network.ip.incoming.datagrams
+                type: float
+                comment: "Cumulative incoming datagrams"
+            -
+                name: hardware.network.ip.outgoing.datagrams
+                type: float
+                comment: "Cumulative outgoing datagrams"
+            -
+                name: hardware.network.ip.incoming.blocks
+                type: float
+                comment: "Cumulative incoming blocks"
+            -
+                name: hardware.network.ip.outgoing.blocks
+                type: float
+                comment: "Cumulative outgoing blocks"
+            -
+                name: hardware.system_states.cpu.idle
+                type: float
+                comment: "CPU Percent idle"
+          formatType: fixed_format
+          formatSubType: delimitedAscii
+          fullList: true
+          numFields: 22
diff --git a/javatoscachecker/checker/src/test/tosca/ucpe_schema.yml b/javatoscachecker/checker/src/test/tosca/ucpe_schema.yml
new file mode 100644
index 0000000..5c5ac5a
--- /dev/null
+++ b/javatoscachecker/checker/src/test/tosca/ucpe_schema.yml
@@ -0,0 +1,403 @@
+tosca_definitions_version: tosca_simple_yaml_1_0_0
+description: CCD uCPE specific data types
+
+metadata:
+  template_name: uCPE_schema
+  template_version: "0.1"
+
+imports:
+  - tosca/tosca-network-types.yaml
+
+data_types:
+
+  routing-rule:
+    properties:
+      logical-interface-name:
+        type: string
+      ip-version:
+        type: string
+      mtu:
+        type: integer
+      is-unnumbered:
+        type: boolean
+      unnumbered-local-address:
+        type: string
+      unnumbered-remote-address:
+        type: string
+      cos-model:
+        type: string
+      pe-shaping:
+        type: string
+      bgp-v4-neighbor-address:
+        type: string
+      bgp-v4-peer-as:
+        type: string
+      bgp-v4-md5-key:
+        type: string
+      bgp-v4-my-as:
+        type: string
+      bgp-v6-neighbor-address:
+        type: string
+      bgp-v6-peer-as:
+        type: string
+      bgp-v6-md5-key:
+        type: string
+      bgp-v6-my-as:
+        type: string
+      bgp-v4-keep-alive-timer:
+        type: string
+      bgp-v6-keep-alive-timer:
+        type: string
+      bgp-v4-hold-timer:
+        type: string
+      bgp-v6-hold-timer:
+        type: string
+      v4-isp-lan-ip-blocks:
+        type: list
+        entry_schema: string                
+      v6-isp-lan-ip-blocks:
+        type: list
+        entry_schema: string
+
+node_types:
+
+  com.att.d2.resource.ucpe.networkInterface:
+    derived_from: tosca.nodes.Root
+    properties:
+      service_port_name:
+        type: string                    
+      physical_port_name:
+        type: string                    
+      physical_speed:
+        type: integer
+      physical_speed_units:
+        type: string   
+        default: "Gbps"
+    requirements:
+      - host:
+          capability: com.att.d2.capabilities.hostedOn
+#          node: com.att.d2.resource.uCPE
+    capabilities:
+      link: tosca.capabilities.network.Linkable 
+
+#do not know to what degree we still need the two specalized versions below
+  com.att.d2.resource.ucpe.lan_networkInterface:
+    derived_from: com.att.d2.resource.ucpe.networkInterface
+    requirements:
+      - host:
+          capability: com.att.d2.capabilities.hostedOn
+          node: com.att.d2.resource.uCPE
+
+  com.att.d2.resource.ucpe.wan_networkInterface:
+    derived_from: com.att.d2.resource.ucpe.networkInterface
+    properties:
+      internet_connection_type:
+        type: string
+        default: "AVPN"
+        constraints:
+          - valid_values: ["AVPN", "AVPNIVLAN", "3RDPARTYINTERNET", "MIS", "GMIS", "ASE", "ASEOD", "3RDPARTYETHERNET", "3RDPARTYMPLS", "HSIA-E"]
+    requirements:
+      - host:
+          capability: com.att.d2.capabilities.hostedOn
+          node: com.att.d2.resource.uCPE
+
+  
+#the participation of a network interface in a VLAN needs to carry a 'tag' attribute (tagged/untagged values)
+#previously we attached this attribute to the Port 
+#  com.att.d2.resource.ucpe.lan_port: 
+#    properties:             
+#      tag:
+#        type: string
+#        default: "tagged"
+#        constraints: 
+#          - valid_values: [tagged, untagged]
+#
+# now it has to go in the relationship between the networkInterface and the VLAN, i.e. LinksTo
+#
+  
+  com.att.d2.resource.ucpe.vlan:
+# can't use as a base type anymore as it has a Linkable capability 
+#    derived_from: tosca.nodes.network.Network
+    properties: 
+      vlan_id: 
+        type: string
+    requirements:  
+      - link:
+          capability: tosca.capabilities.network.Linkable          
+          node: com.att.d2.resource.ucpe.networkInterface
+          relationship: tosca.relationships.network.LinksTo
+      - binding:
+          capability: tosca.capabilities.network.Bindable
+          node: com.att.d2.resource.ucpe.VNF
+          relationship: tosca.relationships.network.BindsTo
+  
+         
+  #virtual network functions to be hosted by a uCPE
+  com.att.d2.resource.ucpe.VNF:
+    derived_from: tosca.nodes.Root
+    properties:
+      att-part-number:
+        type: string
+        constraints:
+          - max_length: 255
+ 
+      vendor-name:
+        type: string
+        constraints:
+          - max_length: 255
+      vendor-part-number:
+        type: string
+        constraints:
+          - max_length: 255
+      vendor-model:
+        type: string
+        constraints:
+          - max_length: 255
+      vendor-model-description:
+        type: string
+        constraints:
+          - max_length: 255
+
+      vcpu-default:
+        type: integer
+        constraints:
+          - less_or_equal: 16
+      vcpu-min:
+        type: integer
+        constraints:
+          - less_or_equal: 16
+      vcpu-max:
+        type: integer
+        constraints:
+          - less_or_equal: 16
+ 
+      vmemory-default:
+        type: integer        
+      vmemory-units:
+        type: string
+        default: "GB"
+      vmemory-min:
+        type: integer
+        constraints:
+          - less_or_equal: 16
+      vmemory-max:
+        type: integer
+        constraints:
+          - less_or_equal: 16
+ 
+      vdisk-default:
+        type: integer
+      vdisk-units:
+        type: string
+        default: "GB"
+      vdisk-min:
+        type: integer
+        constraints:
+          - less_or_equal: 16
+      vdisk-max:
+        type: integer
+        constraints:
+          - less_or_equal: 128
+
+#what is this guy??
+      vnf-type: 
+        type: string
+
+      software-version: 
+        type: version
+      software-version-state:
+        type: integer
+      software-file-name: 
+        type: string
+        constraints:
+          - max_length: 255
+
+      vnf-feature: 
+        type: list
+        entry_schema: string
+
+      vnf-instance-id:
+        type: string
+        constraints:
+          - max_length: 255
+
+      management-option:
+        type: string
+        default: ATT
+        constraints:
+          - valid_values: ["CUSTOMER", "ATT"]
+ 
+    requirements: 
+      - host:
+          capability: com.att.d2.capabilities.hostedOn
+ 
+    capabilities:
+      binding:
+        type: tosca.capabilities.network.Bindable
+        occurrences: [1,UNBOUNDED]      
+
+
+  com.att.d2.resource.uCPE: # base node type for uCPE
+    derived_from: tosca.nodes.Root
+    properties: 
+      att-part-number:
+        type: string                
+      vendor-name:
+        type: string                
+        required: true
+      vendor-model:
+        type: string                
+        required: true
+            
+      total-vcpu:
+        type: integer              
+        description: number of vCPUs
+      total-memory:
+        type: integer               
+        description: GB
+      total-disk:
+        type: integer                
+        description: GB
+            
+      base-system-image-file-name: 
+        type: string
+      linux-host-vendor:
+        type: string
+      linux-host-os-version:
+        type: version
+      base-system-software:
+        type: string
+      jdm-vcpu:
+        type: integer
+      jdm-memory:
+        type: integer
+        description: GB
+      jdm-disk:
+        type: integer
+        description: GB
+      jdm-version:
+        type: string
+      jcp-vcpu:
+        type: integer
+      jcp-memory:
+        type: integer
+        description: GB
+      jcp-disk:
+        type: integer
+        description: GB
+      jcp-version:
+        type: version
+
+    capabilities: 
+      vnf_hosting: 
+        type: com.att.d2.capabilities.hostedOn
+        valid_source_types: [com.att.d2.resource.ucpe.VNF]
+        description: Provides hosting capability for VNFs   
+      WAN_connectivity:
+        type: com.att.d2.capabilities.hostedOn
+        valid_source_types: [com.att.d2.resource.ucpe.wan_networkInterface]
+        description: external WAN1 n/w interface
+        occurrences: [1,2]
+      LAN_connectivity:
+        type: com.att.d2.capabilities.hostedOn
+        valid_source_types: [com.att.d2.resource.ucpe.lan_networkInterface]
+        description: external LAN n/w interface
+        occurrences: [1,8]
+
+# specific VNFs
+
+  com.att.d2.resource.vRouter: 
+    derived_from: com.att.d2.resource.ucpe.VNF
+    properties: 
+      management-v6-address:
+        type: string
+      nm-lan-v6-address: 
+        type: string
+      nm-lan-v6-prefix-length:
+        type: string
+      management-v4-address:
+        type: string
+      nm-lan-v4-address:
+        type: string
+      nm-lan-v4-prefix-length:
+        type: string
+ 
+      routing-instance-name:
+        type: string
+      routing-instances:                   
+        type: map
+        entry_schema:                   
+          type: routing-rule
+
+  com.att.d2.resource.vWANx: 
+    derived_from: com.att.d2.resource.ucpe.VNF
+    properties: 
+#      att-part-number:
+#        type: string
+#        default: "VCX-SUB-00255-U"
+      vendor-name:
+        type: string
+        default: "VendorX"
+      vendor-model:
+        type: string
+        default: "WANx-VM00"
+ 
+      vcpu-default:
+        type: integer
+        default: 1
+      vcpu-min:
+        type: integer
+        default: 1
+      vcpu-max:
+        type: integer
+        default: 1
+ 
+      vmemory-default:
+        type: integer
+        default: 1
+      vmemory-min:
+        type: integer
+        default: 1
+      vmemory-max:
+        type: integer
+        default: 1
+ 
+      vdisk-default:
+        type: integer
+        default: 20
+      vdisk-min:
+        type: integer
+        default: 2
+      vdisk-max:
+        type: integer
+        default: 20
+ 
+      vnf-type: 
+        type: string
+        default: "Advanced WANx"
+      software-version:
+        description: "The WANx software version. The value must match the AT&T part number."
+        type: version
+        default: 9.2.0
+ 
+      software-file-name: 
+        type: string
+        default: "vnfImageFilename"
+
+      vnf-instance-id:
+        type: string
+        description: "The WANx hostname."
+
+  com.att.d2.resource.vFW: 
+    derived_from: com.att.d2.resource.ucpe.VNF
+
+
+ 
+############################
+# Customized capability types definitions
+############################
+capability_types:
+    
+  com.att.d2.capabilities.hostedOn:
+    derived_from: tosca.capabilities.Root
+    
diff --git a/javatoscachecker/checker/src/test/tosca/workflow_1.yaml b/javatoscachecker/checker/src/test/tosca/workflow_1.yaml
new file mode 100644
index 0000000..fda6a27
--- /dev/null
+++ b/javatoscachecker/checker/src/test/tosca/workflow_1.yaml
@@ -0,0 +1,46 @@
+tosca_definitions_version: tosca_simple_yaml_1_1_0
+
+imports:
+  - example: tosca/tosca-examples-types.yaml
+
+topology_template:
+
+  inputs:
+    software_version:
+      type: version
+      default: 0.1
+    management_option:
+      type: string
+      default: ATT
+      constraints:
+        - valid_values: [ ATT, CUSTOMER ]
+
+  node_templates:
+    my_server:
+      type: tosca.nodes.Compute
+    mysql:
+      type: tosca.nodes.DBMS.MySQL
+      requirements:
+        - host: my_server
+      interfaces:
+        tosca.interfaces.nodes.custom.Backup:
+#  operations:
+          backup: backup.sh
+  workflows:
+    backup:
+      description: Performs a snapshot of the MySQL data.
+      preconditions:
+        - target: my_server
+          condition:
+            - assert:
+              - state: [{equal: available}]
+        - target: mysql
+          condition:
+            - assert:
+              - state: [{valid_values: [started, available]}]
+              - my_attribute: [{equal: ready }]
+      steps:
+        my_step:
+          target: mysql
+          activities:
+            - call_operation: tosca.interfaces.nodes.custom.Backup.backup