The Synapse Repository Services project is the home of the JSON REST web services for Synapse.
General information for developers may be found here: https://sagebionetworks.jira.com/wiki/display/PLFM/Home
Information on how github branches are used by Synapse may be found here: https://sagebionetworks.jira.com/wiki/display/PLFM/Staging+Deployment%2C+Step+by+Step