Contributors on the WP REST API project have released version 2.0 beta 1, named after Simpsons character Ralph Wiggum. This release is not backwards compatible with version 1, but project lead Ryan McCue assured developers that it is a direct continuation and that the fundamentals of the API haven’t changed.
Documentation for version 2 is now in progress, starting with basic schema docs, and the site has a section that outlines the changes in 2.0 Beta 1 internals and externals. It also includes an example for migrating endpoints from version 1 code to version 2.
Compatibility with future beta releases is not guaranteed and this release comes with a note of caution for testers:
While we believe the API is now stable enough for public testing, we may continue to break the API in the future as we improve it further. Only use the API in development, and do not use version 2 in production environments.
Version 2.0 beta 1 had 23 contributors and many generous companies donated employee time to the project. This is a major milestone for the WP REST API on its journey to being proposed for inclusion in WordPress core. Check out the project’s core merge plan to follow the progress and view steps as they are completed.
Source: WP Tavern