{"slug":"schema-evolution-compat","source_name":"schema-evolution-compat","name":"Schema Evolution Compatibility","description":"Reviews a change to a table, event, or message schema for backward compatibility with the downstream consumers that read it — enforcing additive-only-by-default, optional/defaulted new fields, no in-place rename, no type or domain narrowing, no reuse of a retired field identifier, deprecate-then-remove over a window, and an explicit versioned contract with a chosen compatibility mode. Use when someone is evolving a shared data or event schema that other services, jobs, or teams consume and asks whether the change will break readers. Do NOT use for the production-DDL lock, downtime, and rollback safety of running a migration (that is migration-safety-review), for classifying a function-signature or REST-endpoint diff and its semver bump (that is api-compatibility-classifier), or for designing a brand-new schema with no existing consumers.","version":1,"lift":{"pass_rate_delta_pts":null,"pass_rate_pct":57.1,"total_cases":14,"passed_cases":8,"tokens_delta_pct":663.7,"turns_delta_pct":0,"verdict":"mixed","benchmark_model":"gemini-3.5-flash","grading_method":"judged","completed_at":"2026-07-10T18:48:59.991219+00:00"},"skill_score":0.9782,"benchmark_models":[{"model":"gemini-3.5-flash","headline":false,"delta_pts":null,"with_pass_pct":null,"without_pass_pct":null,"tokens_delta_pct":663.7,"turns_delta_pct":0,"total_cases":14,"cases_aggregated":14,"verdict":"mixed","never_hurt":true,"completed_at":"2026-07-10T18:48:59.991219+00:00","run_id":"5b6e54b2-9f3e-40b9-8c87-622ad7730387","version_number":1,"is_latest_version":true,"gate":"not_comparable"}],"trust":{"skill_safety":"passed","safety_status":"clean","intent_verdict":"safe","content_status":"clean","indexable":false},"license":null,"install_count":1,"manifest_hash":"18cf99450f66349c3f977578deaa96a004a44255a90b31f784bab481e8223bef","raw_url":"https://app.decimal.ai/s/schema-evolution-compat/SKILL.md","scorecard_url":"https://app.decimal.ai/skills/schema-evolution-compat"}