What it is

Microcks is an open source, cloud native API mocking and testing tool and a Cloud Native Computing Foundation incubating project. It lives in the developer tools and API development ecosystem, where teams need to exercise service contracts before implementations are ready or before changes are trusted. The project turns existing API and microservice assets, including OpenAPI specs, AsyncAPI specs, gRPC protobuf, GraphQL schema, Postman collections, and SoapUI projects, into live mocks for applications, testers, and integration pipelines.

The concrete problem it solves is the gap between API design, service implementation, and verification. Instead of maintaining separate mock data, test scripts, and contract checks, Microcks reuses the same specification assets for both mocking and testing. This lets teams run contract conformance and non-regression tests against an API implementation, while also providing mock servers for dependent services, event-driven flows, GraphQL interactions, and asynchronous interfaces.

Key capabilities

• Converts OpenAPI specs, AsyncAPI specs, gRPC protobuf, GraphQL schema, Postman collections, and SoapUI projects into live API mocks.
• Runs contract conformance and non-regression tests against API implementations by reusing the same imported assets.
• Supports event-driven and asynchronous API workflows through AsyncAPI specification and event-driven project topics.
• Provides CI integrations with Jenkins, GitHub Actions, and Tekton through a simple command-line interface.
• Targets cloud native delivery environments, with Kubernetes and CNCF listed among the project topics.

Who uses it and how

• Teams use existing specification files and collection formats to create live mocks for services before implementations are complete.
• Teams use Microcks to verify that a service implementation conforms to its contract and does not regress after changes.
• Teams place the Microcks CLI into Jenkins, GitHub Actions, and Tekton pipelines so mock creation and contract testing run automatically.
• Teams use AsyncAPI assets to mock and test asynchronous interfaces, including project topics listed under asyncapi-specification and event-driven.

Getting started

The README points users to the Microcks documentation and community resources, and the project is published through a Quay.io container repository, an Artifact Hub package, and a Maven Central artifact identifier. Teams deploying Microcks themselves should start with the documented setup path and choose a published version rather than the development version shown in the build status.

When to use it — and when not to

Microcks is a good fit when a team already has API assets in the formats listed above and wants one tool to create mocks and run contract or non-regression tests. The provided facts do not describe database, storage, SMTP, or hosted-service requirements, so teams needing a fully managed option or a complete self-hosting checklist must inspect the documentation before committing. The project is Apache-2.0 licensed and Java-based, but metadata shows 58 open issues and a development version of 1.15.0-SNAPSHOT, so teams should weigh ongoing maintenance and version selection.