WireMock - flexible, open source API mocking | WireMock

WireMock is the industry standard for scalable API simulation.
The core WireMock engine, free and open source. Self-host or embed in your code.
Start on the docs: Java .NET
The WireMock Cloud API simulation platform with collaboration, advanced features, and AI. Runs anywhere with WireMock Runner.
WireMock is a popular tool to simulate APIs and software dependencies, typically used by teams that need more power and functionality compared to simple mocking. It allows you to test applications without dependencies, simulate edge cases, and develop dependent features in parallel.
Stub HTTP responses and match requests using URL patterns, headers, query parameters, cookies and request body content.
Generate dynamic responses using Handlebars templating with request data, random values, and custom helpers.
Record interactions with real services and play them back during testing for realistic scenarios.
Simulate network faults, delays, and malformed responses to test your application's resilience.
Verify that your application made the expected requests with the correct parameters and timing
Extend WireMock with custom request matchers, response transformers, and admin API extensions.
Run as a standalone process, embedded in tests, or deployed as a service in any environment
Seamless integration with JUnit and other testing frameworks for easy test automation.
WireMock Agent Skills and the WireMock remote MCP server (https://mcp.wiremock.cloud/mcp) expose every platform capability to your AI coding agent — build mock APIs, create stubs, and simulate failures without leaving your editor. Pick your client below for the exact install command.
See every client and skill in the docs
Run your API simulations locally, on private cloud, or your CI/CD pipeline - with the full power of WireMock Cloud.
Add the following to your project's pom.xml dependencies:
Then follow the next steps for JUnit 5+ or plain Java.
Add the following to your project's build.gradle:
Then follow the next steps for JUnit 5+ or plain Java.
Add the following to your project's build.gradle.kts:
Then follow the next steps for JUnit 5+ or plain Java.
Add the following to your project’s build.sbt:
Download the latest standalone JAR then run the following in a terminal:
Learn more in the running standalone guide.
Run the following in a terminal:
Learn more in the Docker guide.
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