SO API Handler utilizes RESTful interfaces to interact with consumer applications. The SO interface is used to orchestrate VNFs, allow for manual task completion, and send vnf replace requests. It contains both the SOServiceInstantiation API and SOManualTasks API.

The SOServiceInstantiation API handles service instance requests, and supports both macro and aLaCarte orchestrations. Change management operations, activation and deactivation of service instances, and new requests for configuration resources are handled by this API. This API is currently set for version 6 ("v6") while also supporting versions 4 and 5 ("v4", "v5") minus additional "v6" features.

The SOManualTasks API handles queries about open manual tasks. This API also accepts POST requests containing information about how SO should proceed with handling the open tasks, and resolving the errors. SOManualTasks API currently supports version 1 ("v1").