head to head · open source
fastapi vs hey-api
fastapi has 102,402 GitHub stars, 9,903 forks, 78 open issues and last shipped 4 days ago. hey-api has 5,416 stars, 434 forks, 630 open issues and last shipped 25 days ago. fastapi leads on adoption by 1,791% (102,402 vs 5,416 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 | ★ 102K | ★ 5.4K |
| License | MIT | MIT |
| Written in | Python | TypeScript |
| Last push | 2026-09-14 | 2026-08-24 |
| Forks | ⑂ 9.9K | ⑂ 434 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick fastapi if
- You weight community size — 102K 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 is an MIT licensed, high performance Python web framework for building APIs with standard Python type hints, aimed at Python developers and teams that need production ready HTTP services with automatic OpenAPI documentation.
read the full fastapi overview →
About hey-api
Hey API is an open source ecosystem for turning API specifications into production ready code. It is distributed as a monorepo containing all of the project's open source packages, with the two primary generators being openapi ts for TypeScript and openapi python for Python. The TypeScript generator ships with more than twenty plugins covering SDKs, Zod schemas, and TanStack Query hooks, while the Python generator produces SDKs and Pydantic models. A supporting library, spec types , provides TypeScript definitions for OpenAPI and JSON Schema specifications with complete inline documentation. The project lives in …
read the full hey-api overview →
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Frequently asked questions
Is fastapi or hey-api more popular?
fastapi has 102,402 GitHub stars and hey-api has 5,416. 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 (102,402 stars) or its MIT licence terms. Choose hey-api if its feature set, stack or MIT licence fits better. Both are self-hostable.