Swagger (later OpenAPI) documents endpoints, parameters, and response schemas in JSONJavaScript Object Notation — a lightweight text format for structured data exchange on the web. or YAML — powering interactive docs, code generators, and APIApplication programming interface — a defined way for programs to talk to each other or to a service. gateways. Tools like Swagger UIUser interface — the parts of software people see and interact with. render `try it out` consoles from the same spec. Example: a `GET /users/{id}` path with typed parameters becomes a typed TypeScriptJavaScript with static types — compiles to JS and powers large front-end and Node codebases. client automatically.

Swagger 1.0 was the first widely adopted RESTRepresentational State Transfer — a style for web APIs using HTTP methods and resource URLs. APIApplication programming interface — a defined way for programs to talk to each other or to a service. description format.

It made APIApplication programming interface — a defined way for programs to talk to each other or to a service. contracts machine-readable and spawned the OpenAPI ecosystem.