Contract Testing GitHub Repositories (2026) · Open Source Tools

Test Automation Made Simple

⚒️ Redocly CLI makes OpenAPI easy. Lint/validate to any standard, generate beautiful docs, and more.

JVM version of Pact. Enables consumer driven contract testing, providing a mock service and DSL for the consumer project, and interaction playback and verification for the service provider project.

Shift-left API Integration | Auto-fix integration drift before integration. Specmatic turns API specifications into executable contracts, continuously verifying that every change made by AI coding agents and engineers stays true to the desired behaviour. Ship AI-ready APIs 10x faster, from intent to implementation, with Spec-Driven API Development.

Enables consumer driven contract testing, providing a mock service and DSL for the consumer project, and interaction playback and verification for the service provider project.

A sandbox for the third-party APIs you depend on. Built from the provider's spec, it fails on purpose, and it replays the exact failure production hit.

Detect breaking changes between OpenAPI 3.0/3.1 specs. Explainable Web UI, CLI and CI gate; local-first and deterministic, with optional AI summaries.

Open-source OpenAPI mock server with cloud hosting and local modes for development, testing, and CI. Generates realistic API responses from specs with latency simulation, error injection, proxy fallback, and request validation. Validated against 2,200+ real-world OpenAPI specs.

PHP version of Pact. Enables consumer driven contract testing, providing a mock service and DSL for the consumer project, and interaction playback and verification for the service provider project

Enables your consumer driven contracts workflow