# FLR004-LAB1 — Contract Drift

Use only the supplied deterministic synthetic fixtures. For each case, build **API Contract Drift Record v1**.

Keep declared contract, observed behavior, and consumer assumption separate. Do not treat a schema-valid OpenAPI file as proof that the synthetic implementation conforms. Do not call every diff breaking: consumer impact is required. Preserve `UNKNOWN` when evidence is incomplete.

The transfer case changes the interaction model from REST request/response to webhook callback. Rebuild the compatibility decision from callback evidence rather than copying the REST rules.