Run your application.

Start a server, make changes, and try your endpoints.

A Karak application collects the endpoints you want to make available. Create one in main.py and add your first endpoint:

from karak import Karak

app = Karak()


@app.get(path="/", methods=["GET"])
async def index():
    return "Hello from Karak"

Start the development server

From the directory containing main.py, run:

uv run uvicorn main:app --reload

Uvicorn is the server that listens for web requests and runs your application. main:app means “use the object named app in main.py.” If you rename the file to example.py, use example:app instead.

Open localhost:8000 to try the endpoint. Keep the terminal open while you use it; Ctrl+C stops the server.

Edit and try again

With --reload, the server restarts when you save changes. Edit the text returned by index(), save, and refresh your browser.

You can add more endpoints to the same app. Each endpoint currently needs an async def function. See define routes for an example you can add to this file.

Use a different port

If another application already uses port 8000:

uv run uvicorn main:app --reload --port 8001

Open localhost:8001 for this server.

Understand a failed request

An HTTP 422 response means a supplied value is missing or invalid. Check the response message and the endpoint’s expected inputs.

An Internal Server Error response means the endpoint encountered an unexpected error. Look at the traceback in the server terminal to find the cause. See send responses for more.

Can I deploy it to production?

Karak is currently for local experimentation and development. The framework is not production-ready, and --reload is a development convenience.

A production experience that covers configuration, resource setup, worker management, visibility into failures, and graceful shutdown is part of what we plan to build. There is no Karak deployment command or managed background-job system to use yet.