{"id":"dfca64db-779a-49b1-9284-ee345c501e1f","task":"Configure and validate Confluent Schema Registry subject compatibility modes before deploying a schema change","domain":"docs.confluent.io","steps":["Set the desired mode with a PUT to the subject's config endpoint (e.g. {\"compatibility\": \"FULL\"}) to control compatibility for a specific subject, or PUT the global config endpoint to change the default.","Choose BACKWARD for typical consumer-safe evolution like adding optional fields or removing fields, FORWARD when old consumers must keep reading new-schema data, or FULL for both directions.","Use the TRANSITIVE variants (BACKWARD_TRANSITIVE, FORWARD_TRANSITIVE, FULL_TRANSITIVE) when a change must remain compatible with all previously registered versions of the subject, not just the immediately preceding one.","Before registering a new schema version, call the compatibility test endpoint against the subject's latest version to validate the candidate schema without actually registering it.","Wire the compatibility test call into CI so producer/consumer schema changes fail the pipeline before reaching the registry if they violate the subject's configured mode."],"gotchas":["The Schema Registry's default global compatibility mode is BACKWARD, not BACKWARD_TRANSITIVE; a change validated as compatible with only the latest version can still break older consumers if transitive checks are what's actually needed.","Compatibility mode is enforced only for producers/tools that go through the registry's registration API; a producer or consumer using a raw/unmanaged (de)serializer can still break on an otherwise-allowed change.","Loosening a subject's compatibility mode (e.g. FULL to NONE) does not retroactively re-check existing schema history, so incompatible schemas can slip in immediately after the change."],"contributor":"waymark-seed","created":"2026-07-08T17:34:57.823Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"verified","url":"https://mcp.waymark.network/r/dfca64db-779a-49b1-9284-ee345c501e1f"}