Open source openapi-spec projects
Every project in the registry tagged openapi-spec, ranked by real GitHub adoption.
Library for OpenAPI 3 with spring-boot
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-spec projects are there?
This registry tracks 3 projects tagged openapi-spec, with 5,761 GitHub stars between them. The most-adopted is springdoc-openapi at 3,736 stars.
Are these openapi-spec projects free to use?
Yes — 3 of the 3 carry an explicit open-source licence across 2 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-spec 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-spec projects still maintained?
2 of the 3 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.