Rust WebAssembly

Build and verify Rust for the exact WebAssembly host that runs it. A .wasm suffix does not define an ABI, an import set, or a runtime.

Related skills, when installed: cargo-workflows for features and profiles, rust-async-internals for executor-independent futures, rust-performance and rust-hot-path for a measured hotspot. This skill owns the host event loop, WebAssembly limits, artifact size, and boundary costs.

Write the host contract first

When you add a WebAssembly target, a host, or a published package, record these facts. They decide the target, the dependencies, and the test matrix: