Briefle words · Code & architecture
Correlation ID
Also called request ID
A unique ID attached to a request and its log entries so one failure can be traced across systems.
Say it to an AI
When POST /v1/bookings fails payment, return a Problem Details (RFC 9457) body: type, title, status and a human detail, plus a stable machine-readable error code (e.g. card_expired), the offending field and the correlation ID. Never a generic 'Something went wrong'.
How an expert would brief the stronger version of “Booking API error”.
See it
Try it as a puzzle →An API client showing what a travel booking API returns when the payment step fails.
Why: B returns '"request_id": "req_7Hc2Kx91"', which a user can paste into a support ticket; A gives support nothing to search for.
Related words
Room 1 · Essentials
Learn “Correlation ID” in a five-minute lesson