GitHub has open-sourced an OpenAPI description of its REST API, which has undergone three major revisions since its initial release shortly after the site's launch. This move aims to enhance developer interaction by using the OpenAPI specification, a widely adopted standard that describes the interface of HTTP APIs in a language-agnostic manner. The description includes over 600 operations and is available in two formats: a bundled version for most use cases and a fully dereferenced version for tools with limited support for inline references. This initiative, currently in beta, is built from existing JSON schemas, documented examples, and contract testing, with quarterly updates for GitHub Enterprise Server and more frequent updates for GitHub.com. GitHub encourages contributions to improve the accuracy and consumption of the description, acknowledging the efforts of a dedicated team and highlighting contributions from individuals like Gregor Martynus and the Docs Engineering team.