OpenAPI specification guides and tutorials
Learn how to use OpenAPI to build HTTP APIs that humans and machines can interact with conveniently.
A brief history of OpenAPI
OpenAPI allows to describe how an API works, how a sequence of APIs work together, generate client code, create tests, apply design standards, deploy documentation, and much more.
OpenAPI Benefits
OpenAPI allows to describe how an API works, how a sequence of APIs work together, generate client code, create tests, apply design standards, deploy documentation, and much more.
Schema Composition
Use oneOf, anyOf, and allOf in OpenAPI & JSON Schema for polymorphism and composition.
Representing XML
OpenAPI can describe XML APIs with a little work, learn how!
Schemas and Data Types
Learn about the most important part of OpenAPI: schemas, and data types.
JSON Schema in OpenAPI
Learn how JSON Schema and OpenAPI Schema are similar and how they are different.
Examples & Defaults
Use examples and defaults in OpenAPI to demonstrate API inputs and outputs.
Splitting OpenAPI Documents with $ref
Learn how to use $ref to reduce clutter and repetition in your OpenAPI documents.
HTTP Responses
HTTP Requests
Define HTTP requests in your OpenAPI to help users know the rules on what to send and how.