Context

Dependency injection

The Context is a dict‑like object that stores request‑scoped values. JetWeb creates a separate Context instance for every request and supports automatic parameter injection for handlers and middlewares.

from typing import Callable

from jetweb import Context, HTTPException, JetWeb, Request, Response

db = Database()
app = JetWeb(global_context={"service_name": "example"})


@app.middleware
def auth_middleware(next_handler: Callable, request: Request, context: Context) -> Response:
    token = request.headers.get("Authorization")
    if not token:
        raise HTTPException(status=403, content="Not authenticated")
    context["token"] = token
    return next_handler()


@app.get("/profile")
def profile(db: Database, token: str) -> dict:
    user_id = get_user_id(token)
    user = db.get_user(user_id)
    return user

Context values

JetWeb can inject the following parameters into handlers and middlewares when they are requested by name in the callable signature:

• app — current JetWeb instance.
• request — current Request.
• exception — HTTPException (available after raising exception).
• context — the Context object for the current request; you can add values to it.
• Path parameters parsed from the route.
• Global context values passed via JetWeb(global_context=...) are available for each request.