head to head · open source
fastapi vs hey-api
fastapi has 104,542 GitHub stars, 10,173 forks, 78 open issues and last shipped 2 days ago. hey-api has 5,551 stars, 452 forks, 630 open issues and last shipped 3 days ago. fastapi leads on adoption by 1,783% (104,542 vs 5,551 stars). fastapi is written in Python under MIT; hey-api is written in TypeScript under MIT. fastapi has attracted 10% as many forks as stars, hey-api 8%. fastapi was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 2 topic tags (openapi, python), 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.
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Side by side
| fastapi | hey-api | |
|---|---|---|
| GitHub stars | ★ 105K | ★ 5.6K |
| License | MIT | MIT |
| Written in | Python | TypeScript |
| Last push | 2026-11-01 | 2026-10-31 |
| Forks | ⑂ 10K | ⑂ 452 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick fastapi if
- You weight community size — 105K stars and counting
- You want the MIT license terms
- Your stack matches Python
- You value the larger contributor base for long-term maintenance
pick hey-api if
- You want the hey-api feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches TypeScript
- You evaluated both and hey-api fits your workflow better
About fastapi
FastAPI framework, high performance, easy to learn, fast to code, ready for production Documentation : Source Code : FastAPI is a modern, fast (high performance), web framework for building APIs with Python based on standard Python type hints. The key features are: Fast : Very high performance, on par with NodeJS and Go (thanks to Starlette and Pydantic). One of the fastest Python frameworks available. Fast to code : Increase the speed to develop features by about 200% to 300%. Fewer bugs : Reduce about 40% of human (developer) induced errors. Intuitive : Great editor support. Completion everywhere. Less time…
read the full fastapi overview →
About hey-api
Hey API "OpenAPI codegen that just works." — Guillermo Rauch, CEO of Vercel Manual • Issues • Contribute About Hey API is an ecosystem for turning API specifications into production ready code. It's trusted by thousands of companies – from YC startups to Fortune 500 enterprises – and powers products used by millions worldwide. This is the monorepo containing all open source Hey API packages. For package specific documentation and quick start guides, see the individual repositories below. Packages Package Description openapi ts TypeScript code generator with 20+ plugins for SDKs, Zod schemas, TanStack Query…
read the full hey-api overview →
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Frequently asked questions
Is fastapi or hey-api more popular?
fastapi has 104,542 GitHub stars and hey-api has 5,551. fastapi has the larger community by that measure.
Are fastapi and hey-api free?
Both are open source. fastapi is licensed under MIT and hey-api under MIT. Neither carries a licence fee.
What is the difference between fastapi and hey-api?
fastapi is written in Python and hey-api in TypeScript. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, fastapi or hey-api?
Choose fastapi if you want the larger community (104,542 stars) or its MIT licence terms. Choose hey-api if its feature set, stack or MIT licence fits better. Both are self-hostable.