head to head · open source
one-api vs openapi-generator
one-api has 36,932 GitHub stars, 6,867 forks, 1,036 open issues and last shipped 8 months ago. openapi-generator has 26,745 stars, 7,674 forks, 5,751 open issues and last shipped yesterday. one-api leads on adoption by 38% (36,932 vs 26,745 stars). one-api is written in JavaScript under MIT; openapi-generator is written in Java under Apache-2.0. one-api has attracted 19% as many forks as stars, openapi-generator 29%. openapi-generator was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (api), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
← all 8884 open source comparisons
Side by side
| one-api | openapi-generator | |
|---|---|---|
| GitHub stars | ★ 37K | ★ 27K |
| License | MIT | Apache-2.0 |
| Written in | JavaScript | Java |
| Last push | 2026-01-09 | 2026-09-17 |
| Forks | ⑂ 6.9K | ⑂ 7.7K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick one-api if
- You weight community size — 37K stars and counting
- You want the MIT license terms
- Your stack matches JavaScript
- You value the larger contributor base for long-term maintenance
pick openapi-generator if
- You want the openapi-generator feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Java
- You evaluated both and openapi-generator fits your workflow better
About one-api
One API is a self hosted LLM API management and key redistribution system that exposes many model providers through the standard OpenAI API format, aimed at developers, teams and operators who want a single endpoint, a single key model and a single quota surface across providers.
read the full one-api overview →
About openapi-generator
OpenAPI Generator is an Apache 2.0 licensed Java tool that generates API client libraries, server stubs, documentation, and configuration automatically from an OpenAPI Specification, and it is built for development teams that keep a machine readable API description and want generated code to stay in step with it.
read the full openapi-generator overview →
More in Developer Tools
Related comparisons
More API Development & Testing projects
Compare either of these against the rest of the API Development & Testing field.
Frequently asked questions
Is one-api or openapi-generator more popular?
one-api has 36,932 GitHub stars and openapi-generator has 26,745. one-api has the larger community by that measure.
Are one-api and openapi-generator free?
Both are open source. one-api is licensed under MIT and openapi-generator under Apache-2.0. Neither carries a licence fee.
What is the difference between one-api and openapi-generator?
one-api is written in JavaScript and openapi-generator in Java. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, one-api or openapi-generator?
Choose one-api if you want the larger community (36,932 stars) or its MIT licence terms. Choose openapi-generator if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.