Problem Details for HTTP APIs
Error response formats are the most inconsistent part of most APIs. RFC 9457 gives you a standard shape that clients can handle generically.
What It Defines
Defines a standard JSON format for HTTP API error responses: type (URI), title, status, detail, instance. Replaces ad-hoc error shapes with a consistent, machine-readable error body.
Canonical (Normative)
Convenient (Practical)
The canonical publication point for finalized RFCs. If a protocol is standardized as an RFC, the RFC Editor text is the normative final reference. Published by the IETF, IRTF, IAB, and independent stream.
Related Specs
This is the core contract of every web API, browser request, and server response. You can't design or debug HTTP without knowing this.
JSON is the lingua franca of web APIs. RFC 8259 is short and worth reading once — it clarifies edge cases around numbers, encoding, and trailing commas.