{"slug":"development/contracts/api-events","title":"API, Event & Contract Standards","section":"development","sectionLabel":"Development","status":"unclassified","type":"document","path":"development/contracts/api-events.md","bytes":974,"description":null,"updated":null,"source":"integratewise/Integratewise-docs-wiki","content":"<!-- DOCUMENT CLASS: DEVELOPMENT | SOURCE: 34_API_EVENT_CONTRACT_STANDARDS.md -->\n\n# API, Event & Contract Standards\n\n## API principles\n\n- stable contracts;\n- tenant-scoped requests;\n- authenticated principals;\n- versioned payloads;\n- explicit error semantics;\n- idempotency for mutation;\n- trace/correlation IDs.\n\n## Event principles\n\nEvents are immutable facts about occurrence.\n\nThey do not themselves imply authorization or promotion.\n\n## Command principles\n\nCommands express intent to perform work.\n\nCommands require:\n\n```text\nPrincipal\nWork\nCapability\nAuthority\nPolicy\nIdempotency\n```\n\n## Result principles\n\nResults include:\n\n```text\nStatus\nEvidence\nReceipt\nAttribution\nTimestamp\nError\nReconciliation State\n```\n\n## Schema versioning\n\nBreaking changes require explicit versioning and migration.\n\n## Contract hierarchy\n\n```text\nProduct Contract\n→ Platform Contract\n→ Service Contract\n→ Provider Adapter\n```\n\nProvider API shape must not leak into Product Contract.\n"}