Error codes

Draft

This page is being written. It will reproduce the canonical error catalog from the service so it stays the single source of truth.

The API returns errors as application/problem+json (RFC 9457 Problem Details), with a stable machine-readable code alongside the human-readable title. Clients should branch on the code, not the message.

Will cover

• The Problem Details shape used across the API.
• The full code catalog and the HTTP status each maps to.
• How validation errors are reported.