schemathesis/schemathesis
Schemathesis
Schemathesis is a property-based testing tool and fuzzer for schema-based APIs. It analyzes OpenAPI and JSON Schema specifications to automatically generate test cases that identify crashes, schema violations, and validation bypasses. The project functions as a contract validator and security scanner, verifying that a live server strictly adheres to its defined specifications.
The framework distinguishes itself through stateful API testing, which chains multiple related requests together to uncover bugs that only emerge during complex, multi-step user workflows. It also utilizes response-driven fuzzing to adapt its testing strategy based on server responses, allowing for deeper exploration of API state transitions.
The tool covers a broad range of capabilities including automated API regression, property-based test generation, and minimal test case reduction. It provides utilities to export failures as minimal reproduction commands and supports reporting through network archive files and the Allure visual format.
Schemathesis operates as a command line runner that integrates into CI/CD pipelines, with support for file-based configuration of authentication headers and reporting settings.
