A REST (Representational State Transfer) API is a web service that follows a set of architectural constraints: it uses standard HTTP methods (GET, POST, PUT, PATCH, DELETE) to perform operations on resources identified by URLs, is stateless (each request contains all information needed to complete it), and returns structured data — typically JSON.
REST APIs are the dominant integration pattern for web services because every HTTP client — every programming language, browser, and platform — can call them without additional libraries. The combination of standard methods and JSON responses makes REST APIs predictable, testable, and cacheable.
AlterLab's scraping service is a REST API: POST a JSON request with a URL and options, receive a JSON response with the extracted content, status, and metadata. Authentication uses API key headers rather than OAuth for simplicity. All endpoints are versioned (`/v1/`) to allow non-breaking evolution of the API surface.