Glossary term
What is OpenAPI (formerly Swagger)?
OpenAPI stands for formerly Swagger.
In System Design
A standard file describing a REST API. Example: Generates docs and client SDKs automatically.
Learn it properly · System DesignLesson 30: REST API Design Best PracticesAn API is a contract other teams depend on for years. How to design REST APIs that are predictable: nouns and HTTP methods, honest status codes, one error shape, filtering and pagination, free HTTP features, security basics and OpenAPI.In Backend in Depth
A file that describes a REST API so machines can read it. It is used for docs, generated types and checks for breaking changes.
Learn it properly · Backend in DepthLesson 2: REST API Design Best Practices: Resources, Versioning, Status CodesNouns, not verbs. One error format. Ways to version an API. Idempotency keys for POST, and partial updates.In API Design
A standard file format that describes an HTTP API so tools can make docs, checks, mocks and client code.
Learn it properly · API DesignLesson 7: Documenting APIs: OpenAPI, Contracts and TestingWrite an OpenAPI file, generate docs, validate requests and responses against it, contract tests and mock servers.