Breaking Change Detector Protocol

This skill acts as the API gatekeeper. It prevents accidental deployment of changes that would break existing mobile apps, web clients, or 3rd-party integrations by comparing API contracts offline.

Core assumption: Once an API is published, you no longer control the clients. Removing a field or changing its type will cause production crashes.

0. Context Intake

Before designing, make sure you have the inputs below. Read the previous workflow step's artifact first if it exists. Ask only for what is missing, in a single message, and state any assumption you make instead of blocking.

• Both contract versions (old and new), or the old one plus the proposed change.
• Who consumes the API (public, partners, internal only) and the versioning policy.
• Supported deprecation window, if any.

1. Specification Diff Analysis (Static)

Compare Version A (Current) with Version B (Proposed) and categorize changes based on backward compatibility logic: