Install · Stario

Stario needs Python 3.12 or newer. These docs use uv, but any tool that installs from PyPI works.

uv init --app my-app

cd my-app

uv add "stario>=5,<6"

Or, in an existing project, pip install "stario>=5,<6".

Run an app#

Stario has its own server. main.py ends with asyncio.run(serve(bootstrap)), so the file runs itself.

uv run python main.py                                # runs once

uvx watchfiles 'uv run python main.py' .             # restarts when a file changes

The server listens on http://127.0.0.1:8000. Set STARIO_PORT or STARIO_HOST to change that:

STARIO_PORT=8080 uv run python main.py

On Linux and macOS, uvloop is a faster event loop. Install the extra and run the app on it.

uv add "stario[uvloop]"

import uvloop

from stario import serve

uvloop.run(serve(bootstrap))

Stario is not ASGI. It does not run under Uvicorn or Hypercorn. serve() is the server.
All settings are environment variables with a STARIO_ prefix. Configuration lists them.
Telemetry is on by default. In a terminal you see one tree per request. Telemetry design explains why.

Next: Hello world writes the first app.