The OnSite API is a RESTful web service that lets developers extend the platform to suit their needs be it integrating with other platforms or enhancing reporting capabilities. The OnSite API is only available with licensed installations of OnSite, versions 3.9/2015 and above.

Developers with experience dealing with RESTful APIs will already be familiar with many of the ways that the OnSite API does things.

However, developers will need to be careful as there are a few differences to watch out for when using the OnSite API. The authentication handling is intricate, requiring at least 4 pieces of identifying information with every request. See Authentication for more details. The OnSite API also uses two non-standard HTTP methods in addition to the standard GET/POST/PUT/DELETE: LOCK and UNLOCK. Those are documented in Locking & Unlocking Resources. Parameters in the fields might not be self-evident, and these are documented in the API Reference section.

The purpose of this documentation is to ease new and experienced developers alike into using this API, as well as providing a solid reference when debugging.

New developers working with a demo instance of OnSite are recommended to start at Sending Your First API Request. Developers running their application against a paid license of OnSite should start at Registering Your Application followed by Sending Your First API Request.