OpenAPI Specification (OAS)

The OpenAPI Specification (formerly Swagger) is the dominant industry standard for describing HTTP-based RESTful APIs. OAS describes endpoints, operations, parameters, request/response schemas, authentication, and examples in a machine- and human-readable format. The active versions are 3.0.x and 3.1.0 (which is fully aligned with JSON Schema 2020-12). OpenAPI is governed by the OpenAPI Initiative, a Linux Foundation project, under the Apache 2.0 license.

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apis.yml Raw ↑
aid: specifications:openapi
name: OpenAPI Specification (OAS)
description: The OpenAPI Specification (formerly Swagger) is the dominant industry standard for describing
  HTTP-based RESTful APIs. OAS describes endpoints, operations, parameters, request/response schemas,
  authentication, and examples in a machine- and human-readable format. The active versions are 3.0.x
  and 3.1.0 (which is fully aligned with JSON Schema 2020-12). OpenAPI is governed by the OpenAPI Initiative,
  a Linux Foundation project, under the Apache 2.0 license.
humanURL: https://www.openapis.org/
baseURL: https://spec.openapis.org/oas/latest.html
tags:
- OpenAPI
- REST
- HTTP
- Specification Language
- OpenAPI Initiative
- Linux Foundation
properties:
- type: Documentation
  url: https://learn.openapis.org/
- type: Specification
  url: https://spec.openapis.org/oas/latest.html
  title: OpenAPI Specification (latest)
- type: Specification
  url: https://spec.openapis.org/oas/v3.1.0
  title: OpenAPI 3.1.0
- type: Specification
  url: https://spec.openapis.org/oas/v3.0.3
  title: OpenAPI 3.0.3
- type: GitHubRepository
  url: https://github.com/OAI/OpenAPI-Specification
- type: GitHubOrganization
  url: https://github.com/OAI
  title: OpenAPI Initiative GitHub Organization
- type: Governance
  url: https://www.openapis.org/about
  title: OpenAPI Initiative / Linux Foundation
- type: License
  url: https://www.apache.org/licenses/LICENSE-2.0
  title: Apache 2.0
- type: Tools
  url: https://tools.openapis.org/
  title: OpenAPI Tools Directory
- type: JSONSchema
  url: https://raw.githubusercontent.com/api-evangelist/specifications/refs/heads/main/json-schema/specification-record-schema.json
  title: Specification Record Schema
- type: Examples
  url: https://raw.githubusercontent.com/api-evangelist/specifications/refs/heads/main/examples/openapi-example.json
  title: OpenAPI Specification Record Example