http://docs.services.mozilla.com/ documents the Sync API and response codes, and other Mozilla web services.
Storage
* [[Services/Sync/Server/API/Storage/1.0|1.0]] (deprecated)
* [[Services/Sync/Server/API/Storage/1.1|1.1]] (current)
User (and Misc)
* [[Services/Sync/Server/API/User/1.0|1.0]] (current)
Response Codes
Both APIs share a common set of response codes
* [[Services/Sync/Server/API/ResponseCodes/1.0|1.0]] (current)