head to head · open source
one-api vs emissary
one-api has 36,932 GitHub stars, 6,867 forks, 1,036 open issues and last shipped 8 months ago. emissary has 4,523 stars, 708 forks, 442 open issues and last shipped yesterday. one-api leads on adoption by 717% (36,932 vs 4,523 stars). one-api is written in JavaScript under MIT; emissary is written in Python under Apache-2.0. one-api has attracted 19% as many forks as stars, emissary 16%. emissary was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (api-gateway), 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
| one-api | emissary | |
|---|---|---|
| GitHub stars | ★ 37K | ★ 4.5K |
| License | MIT | Apache-2.0 |
| Written in | JavaScript | Python |
| Last push | 2026-01-09 | 2026-09-17 |
| Forks | ⑂ 6.9K | ⑂ 708 |
| 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 emissary if
- You want the emissary feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Python
- You evaluated both and emissary 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 emissary
Emissary ingress is an open source Kubernetes native API gateway, Layer 7 load balancer, and Kubernetes Ingress built on the Envoy Proxy. The project is written in Python, distributed under the Apache 2.0 license, and is a CNCF incubation project formerly known as Ambassador API Gateway. It lives in the cloud native ecosystem and targets microservice platforms that already use Kubernetes for scaling and resiliency.
read the full emissary overview →
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Frequently asked questions
Is one-api or emissary more popular?
one-api has 36,932 GitHub stars and emissary has 4,523. one-api has the larger community by that measure.
Are one-api and emissary free?
Both are open source. one-api is licensed under MIT and emissary under Apache-2.0. Neither carries a licence fee.
What is the difference between one-api and emissary?
one-api is written in JavaScript and emissary in Python. 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 emissary?
Choose one-api if you want the larger community (36,932 stars) or its MIT licence terms. Choose emissary if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.