Error Code Registry v1

Normative source: docs/03-PROTOCOL-SPEC.md sections 2, 3, 6, 7, 8, and 10.

Ajar errors use RFC 9457 application/problem+json and include:

type: stable URI for the class of error
title: short human-readable label
status: HTTP status
detail: implementation-specific explanation
ajar_error_code: stable code from this registry
spec_section: optional spec pointer

Servers SHOULD also send the Ajar-Error-Code HTTP header with the same value.

Most codes are returned by Sites in Problem responses and the Ajar-Error-Code header. Some codes are emitted by the client Kernel in local logs/receipts and never appear on the wire from a site; version/extension negotiation codes may be emitted by either side.

Code	Status	Meaning
`AJAR-SCHEMA-INVALID`	400	Object fails schema validation
`AJAR-VERIFY-BAD-SIGNATURE`	401	Signature is absent, malformed, or does not verify
`AJAR-VERIFY-UNKNOWN-KID`	401	Referenced key id cannot be resolved
`AJAR-VERIFY-DOMAIN-BINDING`	401	Owner key is not bound to the requested domain
`AJAR-VERIFY-EXPIRED`	401	Manifest, mandate, offer, or key is expired
`AJAR-VERIFY-ROLLBACK`	409	Manifest sequence is lower than last accepted sequence
`AJAR-MANIFEST-LOCATION`	409	Manifest served from a path other than `/.well-known/ajar.json`
`AJAR-POLICY-TIER-REQUIRED`	403	Required audience tier is not met
`AJAR-POLICY-DENIED`	403	Owner policy denies this URL, View, or Action
`AJAR-POLICY-RATE-LIMITED`	429	Owner policy rate limit exceeded
`AJAR-MANDATE-MISSING`	403	Required mandate was not provided
`AJAR-MANDATE-SCOPE`	403	Mandate scopes do not cover the requested action
`AJAR-MANDATE-CAP`	403	Resolved cost or count exceeds mandate caps
`AJAR-MANDATE-REVOKED`	403	Mandate is revoked, or no revocation status fresh within `cached_ttl` could be obtained
`AJAR-ACTION-RISK-FLOOR`	409	Action attempts to lower required ceremony below risk floor
`AJAR-SIMULATE-REQUIRED`	409	Required SIMULATE step is missing
`AJAR-SIMULATE-DIVERGED`	409	Offer materially diverges from the simulation result; see spec §6
`AJAR-VERSION-BREAKING`	409	Breaking change did not bump the major version (site or kernel emitted)
`AJAR-AEP-REQUIRED`	409	Interoperability-affecting public extension did not follow the AEP process (site or kernel emitted)
`AJAR-OFFER-NOT-FOUND`	404	Offer id was never issued or is not visible to caller
`AJAR-OFFER-EXPIRED`	409	Commit attempted after offer expiry
`AJAR-OFFER-REPLAY`	409	Offer has already been committed or aborted
`AJAR-COMMIT-BAD-BINDING`	401	Commit signature does not bind offer and mandate hashes
`AJAR-CLIENT-PROVENANCE`	409	Client failed to preserve provenance-tagged inert View chunks (kernel emitted)
`AJAR-METERING-PAYMENT-REQUIRED`	402	Payment or settlement proof is required
`AJAR-METERING-SETTLEMENT-FAILED`	402	Settlement adapter rejected the proof
`AJAR-FALLBACK-HUMAN-REQUIRED`	409	Manifest-less R2/R3-equivalent operation requires explicit human confirmation (kernel emitted)

Problem Example

{
  "type": "https://spec.ajarprotocol.org/problems/mandate-cap",
  "title": "Mandate cap exceeded",
  "status": 403,
  "detail": "Offer total INR 250000 exceeds mandate per_tx cap INR 100000.",
  "ajar_error_code": "AJAR-MANDATE-CAP",
  "spec_section": "8.1"
}

Problem Example

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