Getting started

Install

pnpm add -D @avsystem/openapi-ng

openapi-ng requires Node.js 22.12+. See Runtime & platforms for the full compatibility matrix.

Generate from the CLI

openapi-ng generate --input petstore.openapi.yaml --output ./generated

Output:

✓ Generated 5 files from Petstore (3.0.3)
  1 path · 1 operation · 1 schema

  model.generated.ts
  rest.model.ts
  rest.util.ts
  rest.validate.ts
  rest/pet.rest.generated.ts

The full flag list is on the CLI page.

Generate from Node

import { generate } from '@avsystem/openapi-ng';

const result = await generate({
  inputPath: './petstore.openapi.yaml',
  outputPath: './generated',
  emit: ['models', 'angular'],
});

console.log(result.summary);
console.log(result.diagnostics);
console.log(result.artifacts);

Omit outputPath to keep the result entirely in memory.

What you get

Artifact	File	Description
TypeScript models	model.generated.ts	Interfaces, type aliases, and string enum unions
Angular support	rest.model.ts, rest.util.ts	HTTP helper types and request utilities
Forms validation	rest.validate.ts	validateRest helper for signal-forms async validation (optional peer)
Angular services	rest/{tag}.rest.generated.ts	@Injectable service classes grouped by OpenAPI tag

See Angular generator for the shape of the emitted services and example component usage.

Next steps

• Tune naming and mapped types on the Configuration page.
• Walk through the Angular generator to see what the services look like and how to consume them.
• Skim the Diagnostics reference so error codes don’t surprise you later.