API Error Object

Overview

API Error Object is the structured response body that communicates machine-readable details about an API failure. It differs from the HTTP status code, which provides a broad transport-level category but usually not enough application detail.

A typical implementation works as follows: The object includes a stable code, safe message, field-level details, request identifier, and optional retry or documentation information. The API Error Object owner should publish stable error semantics and guidance on whether correction, retry, status lookup, or escalation is appropriate.

Common risks include unstable codes and localized parsing. It is used to let clients classify, display, log, and act on errors consistently. Testing API Error Object should cover malformed input, denied access, rate limits, timeouts, duplicates, asynchronous completion, and version changes.

Core controls require teams to standardize the schema, keep codes stable, separate user and developer messages, sanitize details, and document retryability. Important failure modes include unstable codes, localized parsing, stack traces, sensitive values, excessive nesting, and inconsistent shapes force brittle client logic.

Operational evidence should include error code, HTTP status, request ID, field path, retry flag, documentation reference, and schema version. API Error Object should be documented alongside API Error, API Response Envelope, and API Schema. A successful transport result from API Error Object should not be interpreted beyond the exact API state documented by the provider.

Changes to API Error Object should be checked against older clients, stored payloads, enum growth, default behavior, and retry assumptions. Observability for API Error Object should record operation, version, principal, request ID, latency, retry count, error code, and final state without exposing secrets.