head to head · open source
one-api vs OpenAPI.NET
one-api has 36,955 GitHub stars, 6,870 forks, 1,036 open issues and last shipped 8 months ago. OpenAPI.NET has 1,610 stars, 286 forks, 31 open issues and last shipped 2 days ago. one-api leads on adoption by 2,195% (36,955 vs 1,610 stars). one-api is written in JavaScript under MIT; OpenAPI.NET is written in C# under MIT. one-api has attracted 19% as many forks as stars, OpenAPI.NET 18%. OpenAPI.NET 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 | OpenAPI.NET | |
|---|---|---|
| GitHub stars | ★ 37K | ★ 1.6K |
| License | MIT | MIT |
| Written in | JavaScript | C# |
| Last push | 2026-01-09 | 2026-09-17 |
| Forks | ⑂ 6.9K | ⑂ 286 |
| 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.NET if
- You want the OpenAPI.NET feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches C#
- You evaluated both and OpenAPI.NET 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.NET
OpenAPI.NET is the Microsoft maintained .NET SDK that provides a shared object model for OpenAPI descriptions, together with readers and writers that convert OpenAPI JSON and YAML documents into and out of that model, and it is aimed at C and .NET developers who build, validate, or transform OpenAPI documents in code.
read the full OpenAPI.NET overview →
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Frequently asked questions
Is one-api or OpenAPI.NET more popular?
one-api has 36,955 GitHub stars and OpenAPI.NET has 1,610. one-api has the larger community by that measure.
Are one-api and OpenAPI.NET free?
Both are open source. one-api is licensed under MIT and OpenAPI.NET under MIT. Neither carries a licence fee.
What is the difference between one-api and OpenAPI.NET?
one-api is written in JavaScript and OpenAPI.NET 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 OpenAPI.NET?
Choose one-api if you want the larger community (36,955 stars) or its MIT licence terms. Choose OpenAPI.NET if its feature set, stack or MIT licence fits better. Both are self-hostable.