Smocker (server mock) is a simple and efficient open-source HTTP mock server written in Go. It allows you to simulate any HTTP API to develop and test your applications and microservices without relying on the actual service — whether it is unavailable, still under development, or billed per call.

Its architecture relies on two ports: a mock port that exposes the routes you have declared, and a configuration port with a web interface to register your mocks. Definitions are written in YAML or JSON, with dynamic responses, delays, error codes, and call verification to easily reproduce edge cases.

Lightweight and containerized, Smocker deploys via Docker and integrates naturally into CI/CD pipelines for reproducible integration tests. It is the ideal tool for teams that want to advance autonomously and ensure the reliability of their integrations, on a private and sovereign instance.