Microcks vs Mockttp

Microcks is an open-source tool for mocking and testing APIs and microservices. It works with OpenAPI, AsyncAPI, gRPC/Protobuf, GraphQL schemas, and SOAP, and can build mock responses from examples, generate realistic data, or alter mock data and responses dynamically. It also checks provider and consumer contracts against live implementations and specification versions, and automates checks in CI/CD pipelines with integrations for GitHub Actions, Jenkins, GitLab CI, and Tekton. Containerized deployment supports on-premises, cloud, and developer-laptop use; its Uber distribution is intended for laptop work and unit tests, using ephemeral in-memory MongoDB. The free, community marketplace for API mocks and test suites is enabled by default. Microcks is a CNCF incubating project, with a listed price of free. The public demo is read-only and cannot import APIs or change artifacts. Documentation cautions against production use of the all-managed Kubernetes setup because its single Keycloak and MongoDB instances are not tuned for scalability or security best practices.

Mockttp is a free, open-source JavaScript library for intercepting, transforming, or testing HTTP requests and responses. It supports integration tests in Node.js and browsers, including transparent proxying and HTTPS. Its tools can stub responses, verify requests, generate self-signed certificates for HTTPS mocking, and mock traffic inside or outside the process. It can also serve as the basis for custom proxies that capture, inspect, or rewrite traffic. For parallel tests, Mockttp can automatically configure ports, mock URLs, and proxy settings. It works with promise-capable testing tools and HTTP clients; Mocha, Chai, and Superagent appear in an example but are optional. Browser tests require an admin server running outside the browser. The setup guide warns against trusting a test certificate authority system-wide or sharing its private key, because either could allow an attacker to impersonate secure connections. Mockttp supports Linux, macOS, Windows, web, and self-hosted use.