API Mock Server Generator

Generate fully functional mock API servers from OpenAPI specs, example responses, or natural language descriptions. Unblock frontend development, test integrations, and simulate edge cases without waiting for the real backend.

Not just static JSON over HTTP. These are intelligent mocks that validate request bodies, return contextually appropriate fake data, simulate pagination, support stateful CRUD operations, and inject failures on demand.

Capabilities:

• Generate Express.js or FastAPI mock servers from OpenAPI 3.x specs
• Stateful CRUD mode with in-memory storage for integration testing
• Error simulation: configurable latency, random failures, forced status codes
• Realistic fake data generation with Faker matching schema constraints
• Docker-ready output for portable mock environments
• Zero-dependency static JSON mode for the simplest cases
• Contract testing integration patterns
• Pagination, query parameter handling, and path variable support

Use when: Frontend blocked on backend APIs, integration tests need deterministic responses, demoing without a live backend, simulating error conditions for resilience testing, or contract testing.

Works with: Any frontend framework, any test runner, CI/CD pipelines, Docker.