What's the relationship/differences between wasm-c-api and wasi-sdk

[leonwanghui]

Hi all, recently I'm going to develop a C/C++ app that can be built in WASM module, then adopted in wasmtime environment.

When I look through the WebAssembly repository, there are two projects (wasm-c-api and wasi-sdk) listed. When I found wasmtime is relied to wasm-c-api to support WASM format, I have several questions listed below:

• What's the difference between wasm-c-api and wasi-sdk?
• Why wasmtime is relied on wasm-c-api rather than wasi-sdk to support WASI standard directly?
• Can wasmtime support the wasm-based app compiled with wasi-sdk?

Maybe I have some misunderstanding between these two projects, would be appreciated if anyone could offer some suggestion.

[bjorn3]

wasi-sdk is for programs that are compiled to wasm. wasm-c-api is for native programs to embed a wasm runtime.

[leonwanghui]

Can wasmtime support the wasm-based app compiled with wasi-sdk?

@bjorn3 Thanks for clarification. Does that mean I can use wasmtime to run wasm compiled with wasi-sdk? Is there some version compatible constraints on them?

[bjorn3]

Does that mean I can use wasmtime to run wasm compiled with wasi-sdk?

Yes

Is there some version compatible constraints on them?

As far as I know wasmtime supports all currently existing versions of WASI. In fact wasmtime is kind of the playground to implement new WASI api's.

[leonwanghui]

@bjorn3 Thanks a lot! I'll have a try recently : )