asgi_user_perspective.py

import asyncio
from contextlib import asynccontextmanager
import contextvars

ctxvar = contextvars.ContextVar("ctx")

@asynccontextmanager
async def lifespan():
    ctxvar.set("spam")
    yield

async def endpoint():
    assert ctxvar.get() == "spam"

async def main():
    async with lifespan():
        await endpoint()  # repepatedly called