trio-asyncio is a re-implementation of the asyncio mainloop on top of Trio.

trio-asyncio requires at least Python 3.9. It is tested on recent versions of 3.9 through 3.13.

Trio has native concepts of tasks and task cancellation. Asyncio is based on callbacks and chaining Futures, albeit with nicer syntax, making handling failures and timeouts fundamentally less reliable, especially in larger programs. Thus, you really want to base your async project on Trio.

On the other hand, there are quite a few asyncio-enhanced libraries. You really don't want to re-invent any wheels in your project.

Thus, being able to use asyncio libraries from Trio is useful. trio-asyncio enables you to do that and more.

trio_asyncio does not try to magically allow calling await trio_code() from asyncio or vice versa. There are multiple reasons for this; the executive summary is that cross-domain calls can't be made to work correctly, and any such call is likely to result in an irrecoverable error. You need to keep your code's asyncio and trio domains rigidly separate.

Fortunately, this is not difficult.

Trio-Asyncio's documentation is too large for a README.

For further information, see the manual on readthedocs.

Like Trio, trio-asyncio is licensed under both the MIT and Apache licenses. Submitting a patch or pull request implies your acceptance of these licenses.

Testing is done with pytest. Test coverage is pretty thorough; please keep it that way when adding new code.

See the Trio contributor guide for much more detail on how to get involved.

Contributors are requested to follow our code of conduct in all project spaces.

Matthias Urlichs <matthias@urlichs.de> originally wrote trio-asyncio. It is now maintained by the Trio project.