What is OpenAPI Code Generation?
OpenAPI lets you describe your REST API in a YAML/JSON file. With code generators, you can produce typed API clients, server stubs, documentation, and tests automatically from that schema.
Benefits
- Strong typing: generated client has correct TypeScript types.
- Consistency: client and server always synchronized.
- Productivity: writing a client manually is tedious and error-prone.
- Living documentation: the OpenAPI schema is the source of truth.
openapi-generator
The most complete tool, maintained by OpenAPI Tools.
npx @openapitools/openapi-generator-cli generate \
-i spec.yaml \
-g typescript-axios \
-o src/generated
openapi-typescript
Focused TypeScript generator. Produces types and typed fetch functions.
npm install --save-dev openapi-typescript
npx openapi-typescript spec.yaml -o src/types/api.ts
Best practices
- Version your OpenAPI schema alongside code.
- Generate the client in CI, not manually.
- Use the generated client in tests to verify consistency.
Want to generate API clients automatically? At Vynta we integrate OpenAPI Code Generation.