WireMock

A flexible open-source API mock server for stubbing and simulating HTTP-based APIs. Features a built-in admin web UI, request matching, response templating, fault simulation, and record/playback of real API traffic.

What You Can Do After Deployment

1. Visit your domain — open the WireMock admin UI at /__admin/webapp
2. Create stubs — define URL patterns and response bodies via the UI or API
3. Send requests — point your application at the mock server
4. Simulate faults — add delays, connection resets, or chunked responses
5. Record traffic — proxy to a real API and record responses for later playback

Key Features

• Built-in admin web UI for managing stubs
• Flexible request matching by URL, headers, query params, and body
• Response templating with Handlebars syntax
• Fault simulation: delays, connection resets, random errors
• Record and playback mode — proxy real APIs and save responses
• Stateful behavior with scenarios for multi-step workflows
• Request journal for inspecting received requests
• JSON and XML response body matching
• Regex and JSONPath-based matchers
• REST API for programmatic stub management
• Persistent stub storage across restarts

License

Apache-2.0 — GitHub | Website