asyncio, Trio and AnyIO

Every async policy works on asyncio and Trio, and therefore on AnyIO with either backend. There is nothing to configure and no extra dependency: nopanic detects the running library on each call.

import trio
from nopanic import retry, timeout

@retry(attempts=3, on=ConnectionError)
@timeout(5.0)
async def fetch():
    ...

trio.run(fetch)

Concern	asyncio	Trio
Waiting (retry backoff, rate limits)	asyncio.sleep	trio.sleep
timeout	asyncio.timeout (3.11+), wait_for (3.10)	cancel scope
bulkhead	one asyncio.Semaphore per loop	one trio.Semaphore per trio.run
cache single-flight	shared future per loop	trio.Event per run
hedge	tasks, losers cancelled and reaped	nursery; you get the original exception, never an ExceptionGroup
Cancellation	CancelledError	trio.Cancelled

Cancellation is never treated as a failure: a cancelled breaker probe releases its slot, a cancelled rate-limit waiter gives its token back, a cancelled cache leader hands over to its followers.

Trio is detected only if your application imported it; nopanic never imports it on its own.