Oracle SOA Suite Java API Reference (Javadoc)
All Oracle SOA Suite APIs (B2B, BPEL, Rules, OSB, infrastructure, UMS, etc.) javadocs are available in the Oracle SOA Suite API References section in the document library.
Oracle BPEL Process Manager has a public Java API for interacting with the server.
The BPEL Console uses the Java API for all of it's operations, so you can write Java to programmatically perform any of the actions you see in the BPEL Console.
The Javadoc for the API is installed when you install Oracle BPEL Process Manager and resides in: SOA_HOME/bpel/docs/apidocs. The Javadoc listed here overrides the Javadoc installed for the versions listed below, and will be updated periodically.