head to head · open source
one-api vs NSwag
one-api has 36,932 GitHub stars, 6,867 forks, 1,036 open issues and last shipped 8 months ago. NSwag has 7,365 stars, 1,360 forks, 2,057 open issues and last shipped 11 days ago. one-api leads on adoption by 401% (36,932 vs 7,365 stars). one-api is written in JavaScript under MIT; NSwag is written in C# under MIT. one-api has attracted 19% as many forks as stars, NSwag 18%. NSwag was the more recently maintained of the two, and both are self-hostable with no licence fee.
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
| one-api | NSwag | |
|---|---|---|
| GitHub stars | ★ 37K | ★ 7.4K |
| License | MIT | MIT |
| Written in | JavaScript | C# |
| Last push | 2026-01-09 | 2026-09-07 |
| Forks | ⑂ 6.9K | ⑂ 1.4K |
| 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 NSwag if
- You want the NSwag feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches C#
- You evaluated both and NSwag 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 NSwag
NSwag is an MIT licensed Swagger/OpenAPI 2.0 and 3.0 toolchain written in C for .NET, ASP.NET Core, and TypeScript developers who need to generate OpenAPI specifications from ASP.NET Web API controllers and generate C or TypeScript clients from those specifications.
read the full NSwag overview →
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Frequently asked questions
Is one-api or NSwag more popular?
one-api has 36,932 GitHub stars and NSwag has 7,365. one-api has the larger community by that measure.
Are one-api and NSwag free?
Both are open source. one-api is licensed under MIT and NSwag under MIT. Neither carries a licence fee.
What is the difference between one-api and NSwag?
one-api is written in JavaScript and NSwag in C#. 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 NSwag?
Choose one-api if you want the larger community (36,932 stars) or its MIT licence terms. Choose NSwag if its feature set, stack or MIT licence fits better. Both are self-hostable.