What problem does it solve? Backend API, OpenAPI, or JSON Schema changes often leave stale types, mappers, form state, fixtures, and tests scattered across the frontend. This Skill systematically traces a contract change through the full frontend data flow so nothing is silently left behind. ## Core Features & Use Cases - Semantic Delta Modeling: Classifies each contract change as breaking, additive, or ambiguous across transport, request, response, and behavior dimensions. - Impact Matrix: Traces symbols, imports, and runtime data flow through clients, mappers, state, forms, UI, fixtures, and tests before any code is edited. - Compatibility Strategy & Verification: Selects atomic migration, dual-read/write, or versioned adapters, then verifies with static checks, boundary tests, and runtime evidence. - Use Case: When the backend renames a response field or changes an enum, use this Skill to update the generated client, boundary mapper, form hydration, UI labels, and tests, then confirm no stale consumers remain. ## Quick Start Use the propagate-api-contract-changes skill to apply this backend contract change across the frontend and verify every affected layer.
