OpenApi3-TS

June 1, 2026 · View on GitHub

TypeScript library to help building OpenAPI 3.x compliant API contracts.

Version 4

Breaking change notice:

Version 4.0 Adds explicit support for OAS 3.0 and OAS 3.1 as separate implementations.

OAS 3.2 is available as a third parallel implementation (oas32). The JSON Schema dialect is unchanged between 3.1 and 3.2 (Draft 2020-12); 3.2 adds document-structure fields such as streaming itemSchema/itemEncoding/prefixEncoding on the Media Type Object, the reusable mediaTypes component bucket, the query HTTP method and additionalOperations, Tag hierarchies, the XML nodeType, and the OAuth device authorization flow.

To use version 3.2 import

import { oas32 } from 'openapi3-ts';

Or directly import from subpath:

import { OpenAPIObject, OpenApiBuilder } from 'openapi3-ts/oas32';

To use version 3.1 import

import { oas31 } from 'openapi3-ts';

Or directly import from subpath:

import { OpenAPIObject, OpenApiBuilder } from 'openapi3-ts/oas31';

To use version 3.0 import

import { oas30 } from 'openapi3-ts';

Or directly import from subpath:

import { OpenAPIObject, OpenApiBuilder } from 'openapi3-ts/oas30';

Includes

/src/model TS typed interfaces for helping building a contract.
/src/dsl Fluent DSL for building a contract.

Install

Install package via npm:

npm i --save openapi3-ts

Documentation, Versions, and Changelog

Documentation.
See changelog for version and changes.

References

OpenAPI spec 3.2.0. https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.2.0.md
OpenAPI spec 3.1.0. https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.1.0.md

License

Licensed under the MIT License.

Credits

Contact: Pedro J. Molina | github: pjmolina | twitter: pmolinam