error-code-design

What problem does it solve?

This Skill designs error responses that are safe, consistent, and diagnosable, so clients can reliably branch on machine-readable codes instead of fragile messages, and operators can trace failures without leaking internal details.

Core Features & Use Cases

• Stable error code governance: Ensures error code/type values remain compatibility contracts over time, preventing breaking changes when wording changes.
• Secure response shaping: Prevents raw exceptions, stack traces, database/provider details, and internal implementation names from reaching clients.
• Transport- and contract-aligned semantics: Aligns HTTP status decisions with RFC 9110 and defines retryability and correlation behavior so client behavior is predictable.
• Validation and authorization posture: Standardizes field-level validation violations and uses an existence-leakage-aware approach for 404 vs 403 to reduce enumeration risk.

Use it when designing a new service or subdomain’s API error taxonomy, defining retry and idempotency expectations for failure scenarios, or establishing a publishable error catalog that supports long-term client integration.

Quick Start

Use the error-code-design skill to produce an error catalog entry (code taxonomy, HTTP/grpc mapping, user-safe messages, retry guidance, trace/correlation requirements, and validation/authorization rules) for your next API error scenario.