mitti

mitti is a Python ASGI framework designed to unify concurrent and parallel execution behind a synchronous application model.

Application code stays ordinary, synchronous Python. mitti owns the execution machinery and decides how to run it — concurrently on GIL builds, and in true parallel on free-threaded Python.

from mitti import App

app = App()


@app.get("/users/{user_id}")
def get_user(user_id: int):
    return users.get(user_id)

Status

Early alpha. The design is documented in docs/design.md; the MVP covers ASGI, routing, path/query parameters, JSON responses, the request object, dependency injection, basic validation, middleware, lifespan, and a thread-based executor.

Requirements

• Python 3.13+
• ASGI 3
• Free-threaded Python where available (GIL-enabled Python supported as a compatibility mode)

Development

uv sync
uv run pytest

Load testing

See docs/load-testing.md for a practical uvicorn + hey setup and example scripts under loadtest/.