Rest-assured is a Java-based REST API testing framework and HTTP client library designed for automating web service tests. It provides a fluent domain-specific language and assertion library to send HTTP requests and validate response metadata, including status codes, headers, cookies, and bodies.
The framework is distinguished by a method-chaining DSL that creates readable specifications for API interactions. It features a filter-based request interception pipeline, object-mapping serialization for converting Java objects to JSON or XML, and a path-based parsing system to isolate specific fields within response bodies.
The tool covers a broad range of capabilities including structural validation via JSON and XML schemas, session-tracking automation for CSRF tokens and session identifiers, and security management for SSL and various authentication schemes. It also supports mock-client integration for testing web controllers without a full network stack, as well as performance monitoring to measure response times.
