@napi-rs/cli Copy package name

@napi-rs/cli

Cli tools for napi-rs

# or npm, pnpm
yarn add @napi-rs/cli -D
yarn napi build

Requirements

@napi-rs/cli supports Node.js ^20.17.0, ^22.13.0, and >=23.5.0. Earlier Node.js releases are no longer supported by the CLI runtime.

Commands

Disposing generated WASI bindings

Generated WASI bindings expose deterministic cleanup through a non-enumerable symbol on the binding object:

const binding = require('<package>')
const dispose = binding[Symbol.for('napi.rs.wasi.dispose')]

if (dispose) {
  await dispose()
}

The symbol is present only when the loaded binding is WASI. Browser WASI loaders expose it on their default export. Disposal releases the instance: it destroys the emnapi context and then terminates the workers owned by that binding. Before that, the loader calls the binary's napi_prepare_wasm_env_cleanup preparation hook, which shuts the addon's async runtime down while the environment can still call into JavaScript. A registered AsyncRuntime backend quiesces there and its cancelled tasks reject their promises; the built-in Tokio runtime only starts draining, so with it a promise whose task is still running can still be left pending. Settle in-flight work before disposing if that matters.

The same preparation runs on a direct Context.destroy(). destroy() disables JavaScript calls before it runs its cleanup hooks, and the threadsafe function's hook then drops whatever is still queued, so every generated loader shadows destroy on the emnapi context it creates: an embedder, a test harness, or emnapi's own beforeExit auto-destroy gets the barrier too, instead of silently discarding the settlements. Prefer the dispose symbol when you can yield — only dispose() waits for settlements queued from another thread. A destroy() that re-enters from a promise hook while the barrier is still running is a no-op, because the frame that started the barrier destroys the moment it returns; a dispose() that re-enters the same way joins the disposal already running, since its frame yields for the settlement drain before it destroys.

Concurrent calls share one promise, successful disposal is idempotent, and a failed cleanup phase can be retried by calling the same function again. Do not call addon exports after disposal completes.

See WASI targets and loaders for threaded, threadless, browser, and workerd packaging behavior.

Debug mode

DEBUG="napi:*" napi [command]