Microservices: Documenting Inter-Service APIs

This is the second in a series on the perils of microservices. Check out Microservices: The Version Problem too.

Microservice A needs to talk to microservice B. B provides an API of some sort. A uses the API to contact B.

These microservices have entered into an API contract. Since A relies on B, anytime B changes its API, A must be notified and updated. This contractual dependency is usually undocumented not statically verified. That means that in any real system, the contract can and will be broken, especially as the number of contracts in a system increases at a large rate.