wasip3 support

[shuowpro]

Based on the WASI roadmap, the wasip3 preview has been released on wasmtime 37, and it will be officially released on Feb, 2026, wasip3 is a very important version and it should unlock tons of scenarios, what is the plan of supporting it?

[yowl]

As far as async and future support in thr component model.for c# , this is a work in progress. There are some tests in the wit-bindgen repo, and c# is going to slowly get support for passing those tests. Your best bet for tracking that is to follow the PRs .

[shuowpro]

wit-bindgen is meant for C# to be used as a component called by other runtimes. I think we also need to make it support wasmtime calling other wasip3 components. Do we have plan to support it?

[martindevans]

With regards to async; I tried to implement support for it a while ago (see #279), but unfortunately it turned out to be impossible.

The way in which wasmtime implements async on Windows (using fibers) is incompatible with dotnet (dotnet doesn't allow any usage of fibers). This isn't something that's likely to change in either end.

[yowl]

Async support in C# will support calls from other components, and the intention is to support threads when it becomes available in wasi.