The Telligent Community Platform APIs consist of:
These versioned APIs allow developers to customize and innovate on the platform while not having to worry about breaking changes when new versions of the platform are released.
Use the REST web services either when working out of process or even inside widgets with AJAX.
The In-Process API is an upgrade-safe .NET library for building on the Telligent Community platform. The In-Process API is used when working inside the website (or jobs service).
Widget Extensions (or Widget API) expose the In-Process API to widgets. The Widget API also includes functionality not provided by the In-Process API that is useful for widgets like pagers, editors, and utilities for parsing dates, making lists from arrays, etc.
Documentation for the default set of widget APIs is available in this wiki: Widget API documentation. Documentation for currently-installed widget extensions can be found on your Telligent Community site in Administration > Interface > Widgets > API Documentation (the ? icon).