Question 1

How does Phemeral detect my framework?

Accepted Answer

Phemeral analyzes your project structure and code to work out the framework, the package manager, the entrypoint, and start command.

Question 2

Do I need a Dockerfile or config file?

Accepted Answer

No. Detection runs off your source. Just write your code.

Question 3

Which package managers are supported?

Accepted Answer

uv, poetry, and pip via pyproject.toml or requirements.txt. Phemeral looks for a uv.lock, then poetry.lock, then pyproject.toml, then requirements.txt, and uses the first match closest to your repo root.

Question 4

Which versions of Python are supported?

Accepted Answer

Phemeral supports all versions of Python. If your codebase includes a .python-version file, the version specified in the file will be used. When unspecified, Python 3.12 is used.

Question 5

Can I override the start command?

Accepted Answer

Yes. Set a custom start command in the project's Settings tab; saving an empty value returns to autodetection. Custom commands should bind to port 8000.

Question 6

What if my framework isn't listed?

Accepted Answer

Any Python based web app can be hosted on Phemeral. If your framework isn't listed, that just means we haven't written about it yet. But you can certainly still host your app! You may need to use a custom start command in that case.

Question 7

Does it support WebSockets and SSE?

Accepted Answer

Yes. Long-lived connections are supported; see the WebSockets and SSE guide in the docs for the details.

Question 8

Is Django's ASGI setup handled automatically?

Accepted Answer

Yes. Django is treated as ASGI and started with uvicorn on port 8000 unless you set a custom command.

Deploy any Python framework.

FastAPI

Flask

Django

Litestar

Starlette

Sanic

FastHTML

Questions

Ship Python.
Not infrastructure.

Deploy any Python framework.

Supported frameworks

FastAPI

Flask

Django

Litestar

Starlette

Sanic

FastHTML

Questions

How does Phemeral detect my framework?+−

Do I need a Dockerfile or config file?+−

Which package managers are supported?+−

Which versions of Python are supported?+−

Can I override the start command?+−

What if my framework isn't listed?+−

Does it support WebSockets and SSE?+−

Is Django's ASGI setup handled automatically?+−

Ship Python.Not infrastructure.

Ship Python.
Not infrastructure.