head to head · open source
fastapi vs emissary
fastapi has 102,402 GitHub stars, 9,903 forks, 78 open issues and last shipped 4 days ago. emissary has 4,523 stars, 708 forks, 442 open issues and last shipped yesterday. fastapi leads on adoption by 2,164% (102,402 vs 4,523 stars). fastapi is written in Python under MIT; emissary is written in Python under Apache-2.0. fastapi has attracted 10% 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.
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 | emissary | |
|---|---|---|
| GitHub stars | ★ 102K | ★ 4.5K |
| License | MIT | Apache-2.0 |
| Written in | Python | Python |
| Last push | 2026-09-14 | 2026-09-17 |
| Forks | ⑂ 9.9K | ⑂ 708 |
| 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 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 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 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 fastapi or emissary more popular?
fastapi has 102,402 GitHub stars and emissary has 4,523. fastapi has the larger community by that measure.
Are fastapi and emissary free?
Both are open source. fastapi is licensed under MIT and emissary under Apache-2.0. Neither carries a licence fee.
What is the difference between fastapi and emissary?
fastapi is written in Python 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, fastapi or emissary?
Choose fastapi if you want the larger community (102,402 stars) or its MIT licence terms. Choose emissary if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.