Give your application another endpoint.

Choose the URL someone visits and the function that answers it.

A route connects a URL to your code. In the quickstart, / returned a greeting. To add a user endpoint, put this below your existing app = Karak():

@app.get(path="/users/{user_id}", methods=["GET"])
async def user(user_id: int):
    return f"User {user_id}"

Start the server and visit localhost:8000/users/42. The response is:

User 42

Accept a value in the URL

{user_id} marks the part of the URL that can change. Name the function parameter user_id too, and use int to ask for an integer.

Visit /users/7 to receive User 7. Visit /users/alex and Karak returns an HTTP 422 validation response because alex cannot be converted to an integer.

Add optional controls

Use query parameters for values such as filters or page numbers. Add this parameter to the same user endpoint:

@app.get(path="/users/{user_id}", methods=["GET"])
async def user(user_id: int, active: bool = True):
    return f"User {user_id} · active={active}"

Replace the earlier user endpoint with this version rather than registering both. /users/42?active=false responds with User 42 · active=False. If you leave active out, the default True applies.

Continue to read request values for lists, defaults, and other supported types.

Choose an HTTP method

The current decorator takes both path= and methods=. Although it is named app.get, the list supplied in methods determines which methods it accepts. Separate app.post, app.put, and app.delete helpers are not available yet.

The current guides focus on GET endpoints. Automatic JSON request-body handling is still planned.

Prototype limitations

Keep these limitations in mind when trying routes:

Use matching names for path placeholders and function parameters, and annotate every parameter. Mistakes here prevent the endpoint from being added.
Avoid registering different method-specific handlers for the same path. A request can receive HTTP 405 before reaching the intended handler.
An unknown URL currently returns HTTP 500 with Route Not Found, rather than HTTP 404. Check the URL and the routes you have defined.
Keep literal paths simple. Characters such as . and + can be interpreted as patterns instead of matching exactly as written.