Cloud Elements officially joined the Open API Initiative in November last year to continue the momentum behind organizing the world of APIs into easy-to-consume API hubs with standardized, machine-readable documentation.

Over the past few months, the members of the OAI Technical Developer Community (TDC) have been hard at work to make the next version of the OpenAPI Specification a reality: OAS 3.0.

This week sees the release of the first implementer’s draft of OAS v3.0 — officially released as 3.0.0-RC0 — and is a big step forward for the specification.

Some of the key changes you’ll see from v2.0 to v3.0 include:

• The overall structure has been rearranged for easier and extended reusability.
• JSON schema support has been extended to include oneOf, anyOf and not support.
• The structure of parameters has changed to allow the use of schema in them.
• Support for cookie parameters has been added and dataForm parameters have been eliminated.
• Body parameters were extracted to their own entity.
• Support for content type negotiation has been added.
• A new format to allow static linking between responses and future requests has been added.
• Simplified and enhanced security definitions of APIs.
• A callback mechanism to describe WebHooks has been added.

At this point, the specification is feature-complete, and the implementer’s draft is intended to help work through any outstanding issues. We encourage you to get involved by starting to build against OAS 3.0 and submit feedback here.