Runtime & platforms

This page covers the runtimes that can host the openapi-ng generator (the CLI / Node API that turns an OpenAPI spec into TypeScript). For the runtime helpers shipped inside generated output (rest.util.ts / rest.model.ts), see the Angular generator guide.

Primary runtime

openapi-ng targets Node.js as its primary runtime: the generation engine is a Rust binary loaded via NAPI-RS.

Requires Node.js 22.12+.

Bun and Deno are supported on the same native path because both implement N-API and pick up the prebuilt .node artifact directly.

Platforms

Pre-built native binaries are published for:

macOS (x64, ARM64)
Linux glibc (x64, ARM64)
Linux musl (x64, ARM64) — Alpine and other musl-based images
Windows (x64, ARM64)

The correct glibc or musl artifact is selected at load time, so Alpine and distroless images need no extra configuration.

On any other platform (FreeBSD, 32-bit, etc.) the loader falls back to the WebAssembly build if @avsystem/openapi-ng-wasm32-wasi is installed next to @avsystem/openapi-ng; otherwise require throws an explicit unsupported-platform error listing the supported set.

Browsers

The generator also ships as WebAssembly in the platform package @avsystem/openapi-ng-wasm32-wasi. The browser entry of @avsystem/openapi-ng loads it on demand, so bundlers that honour the browser field (Vite, webpack, esbuild) pick the WebAssembly path automatically.

Two requirements:

Add the platform package yourself. napi-rs does not list it among the root package’s optional dependencies, so it is not installed transitively:
Terminal window
```
pnpm add -D @avsystem/openapi-ng @avsystem/openapi-ng-wasm32-wasi
```
Import createGenerate from @avsystem/openapi-ng/browser when you serve the WebAssembly files yourself.
Serve the page cross-origin isolated. The binding uses shared memory, which browsers only enable under these response headers:
```
Cross-Origin-Opener-Policy: same-origin
Cross-Origin-Embedder-Policy: require-corp
```

If the package is missing, bundlers may warn about an unresolvable dynamic import and generate() rejects with E_UNSUPPORTED_RUNTIME at call time.

In the browser, generate() accepts inputContents plus displayPath and returns the artifacts in memory. inputPath and outputPath are rejected with E_INVALID_OPTION because there is no filesystem. If the WebAssembly binding cannot be loaded, generate() rejects with E_UNSUPPORTED_RUNTIME and a message naming the missing package or header.

Try it without installing anything: the playground.

Edge runtimes

Cloudflare Workers, Vercel Edge and Deno Deploy are not verified. The WebAssembly build may run there; open an issue with your findings if you try it.