Open source openapi-specification projects
Every project in the registry tagged openapi-specification, ranked by real GitHub adoption.
The OpenAPI Specification Repository
📘 OpenAPI/Swagger-generated API Reference Documentation
Examples and server integrations for generating the Swagger API Specification, which enables easy access to your REST API
OpenAPI based HTTP Client code generator
Library for OpenAPI 3 with spring-boot
A flexible JSON/YAML linter for creating automated style guides, with baked in support for OpenAPI (v3.1, v3.0, and v2.0), Arazzo v1.0, as well as AsyncAPI v2.x
OpenAPI Diff and Breaking Changes
Fast and light-weight API proxy firewall for request and response validation by OpenAPI specs.
Related tags
Frequently asked questions
How many open source openapi-specification projects are there?
This registry tracks 8 projects tagged openapi-specification, with 77,754 GitHub stars between them. The most-adopted is OpenAPI-Specification at 31,291 stars.
Are these openapi-specification projects free to use?
Yes — 8 of the 8 carry an explicit open-source licence across 3 distinct licences, so there is no licence fee. Where a project also sells a hosted or enterprise version, the self-hosted path remains free.
Which openapi-specification project should I choose?
The list above is ranked by GitHub stars, but stars measure attention rather than fit. Check three things on each card: the licence (permissive versus copyleft), the language it is written in, and the last-push date — a high-star project that has not been pushed in a year is a liability.
Are these openapi-specification projects still maintained?
7 of the 8 were pushed in the last 90 days, and every card shows its exact last-push date so you can see the rest. Sort your shortlist by that date before committing to a migration.