Alex Crichton (Sep 08 2026 at 14:59): Alex Crichton (Sep 08 2026 at 14:59):I wanted to post here that wasm32-wasip3 is now available in Rust and C/C++:
rustup target add wasm32-wasip3 on the nightly channel. Rust 1.100 will include this in stable.We've tried to pretty thoroughly vet wasm32-wasip3 so all basic-to-intermediate usage should likely work, and more advanced usage should probably work but there's always the possibility of bugs. Please report anything you see through normal channels/bug trackers/etc.
In addition to the target itself being made available I'd also like to say that the coop threads feature is also ready for testing at the same time. By default wasm32-wasip3 right now cannot spawn threads and the threading intrinsics are still unstable in Wasmtime for example. That being said I've gotten lots of tests from various places working and lots of development has gone into getting threads working, so it's possible to test out today.
Like with the normal target please file any issues for anything you find. It's roughly expected that coop threads is pretty well tested too so at least basic things should work, but there's always the possibility for bugs.
I believe the rough current plan/timeline is to use the next month or two to validate/vet the coop threads implementation, the spec, etc. Come ~November-ish the hope is to make the threading intrisnics stable in the component model at which point the wasm32-wasip3 target will be switched to by-default supporting threads. Your feedback will help ensure that this goes smoothly and well, so testing is much appreciated!
Last updated: Sep 20 2026 at 19:05 UTC