errors.json

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "version": "0.16.1",
  "description": "PEAC error codes - normative source of truth",
  "errors": [
    {
      "code": "E_INVALID_SIGNATURE",
      "http_status": 400,
      "title": "Invalid Signature",
      "description": "Receipt signature verification failed",
      "category": "verification",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_INVALID_FORMAT",
      "http_status": 400,
      "title": "Invalid Format",
      "description": "Receipt does not conform to JWS format",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_EXPIRED",
      "http_status": 400,
      "title": "Receipt Expired",
      "description": "Receipt has exceeded its expiration time",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_NOT_YET_VALID",
      "http_status": 400,
      "title": "Not Yet Valid",
      "description": "Receipt nbf (not before) time is in the future",
      "category": "validation",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_INVALID_ISSUER",
      "http_status": 400,
      "title": "Invalid Issuer",
      "description": "Receipt issuer claim is invalid or untrusted",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INVALID_AUDIENCE",
      "http_status": 400,
      "title": "Invalid Audience",
      "description": "Receipt audience claim does not match expected value",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_JWKS_FETCH_FAILED",
      "http_status": 503,
      "title": "JWKS Fetch Failed",
      "description": "Failed to fetch public keys from JWKS endpoint",
      "category": "infrastructure",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_KEY_NOT_FOUND",
      "http_status": 400,
      "title": "Key Not Found",
      "description": "Public key with specified kid not found in JWKS",
      "category": "verification",
      "retryable": false,
      "next_action": "retry_with_different_key"
    },
    {
      "code": "E_KID_REUSE_DETECTED",
      "http_status": 400,
      "title": "Kid Reuse Detected",
      "description": "Same kid value used with different key material within the retention window",
      "category": "verification",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_REVOKED_KEY_USED",
      "http_status": 400,
      "title": "Revoked Key Used",
      "description": "Receipt signed with a key listed in the issuer revoked_keys set",
      "category": "verification",
      "retryable": false,
      "next_action": "retry_with_different_key"
    },
    {
      "code": "E_INVALID_AMOUNT",
      "http_status": 400,
      "title": "Invalid Amount",
      "description": "Payment amount is invalid or out of allowed range",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INVALID_CURRENCY",
      "http_status": 400,
      "title": "Invalid Currency",
      "description": "Currency code is not a valid ISO 4217 code",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INVALID_RAIL",
      "http_status": 400,
      "title": "Invalid Payment Rail",
      "description": "Payment rail identifier is not recognized",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_MISSING_REQUIRED_CLAIM",
      "http_status": 400,
      "title": "Missing Required Claim",
      "description": "Receipt is missing a required JWT claim",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_RATE_LIMITED",
      "http_status": 429,
      "title": "Rate Limited",
      "description": "Too many requests, please retry later",
      "category": "infrastructure",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_PAYLOAD_TOO_LARGE",
      "http_status": 413,
      "title": "Payload Too Large",
      "description": "Request body exceeds the maximum allowed size for this transport surface",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_CIRCUIT_BREAKER_OPEN",
      "http_status": 503,
      "title": "Circuit Breaker Open",
      "description": "Service temporarily unavailable due to circuit breaker",
      "category": "infrastructure",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_CONTROL_DENIED",
      "http_status": 403,
      "title": "Control Decision Denied",
      "description": "Control engine denied authorization",
      "category": "control",
      "retryable": false,
      "next_action": "contact_issuer"
    },
    {
      "code": "E_CONTROL_REVIEW_REQUIRED",
      "http_status": 202,
      "title": "Review Required",
      "description": "Control engine requires manual review",
      "category": "control",
      "retryable": true,
      "next_action": "contact_issuer"
    },
    {
      "code": "E_EVIDENCE_NOT_JSON",
      "http_status": 400,
      "title": "Evidence Not JSON-Safe",
      "description": "Evidence contains non-JSON-safe values (NaN, Infinity, undefined, BigInt, Date, Map, Set, functions, symbols, class instances, or cycles)",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INVALID_SUBJECT",
      "http_status": 400,
      "title": "Invalid Subject",
      "description": "Receipt subject claim does not match expected value",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INVALID_RECEIPT_ID",
      "http_status": 400,
      "title": "Invalid Receipt ID",
      "description": "Receipt ID (rid) does not match expected value",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_MISSING_EXP",
      "http_status": 400,
      "title": "Missing Expiration",
      "description": "Receipt is missing required exp claim",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INTERNAL",
      "http_status": 500,
      "title": "Internal Error",
      "description": "An unexpected internal error occurred during verification",
      "category": "infrastructure",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_IDENTITY_MISSING",
      "http_status": 401,
      "title": "Identity Missing",
      "description": "No agent identity attestation provided in request",
      "category": "identity",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_IDENTITY_INVALID_FORMAT",
      "http_status": 400,
      "title": "Identity Invalid Format",
      "description": "Agent identity attestation does not conform to schema",
      "category": "identity",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_IDENTITY_EXPIRED",
      "http_status": 401,
      "title": "Identity Expired",
      "description": "Agent identity attestation has exceeded its expiration time",
      "category": "identity",
      "retryable": false,
      "next_action": "refresh_attestation"
    },
    {
      "code": "E_IDENTITY_NOT_YET_VALID",
      "http_status": 401,
      "title": "Identity Not Yet Valid",
      "description": "Agent identity attestation issued_at time is in the future",
      "category": "identity",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_IDENTITY_SIG_INVALID",
      "http_status": 401,
      "title": "Identity Signature Invalid",
      "description": "Agent identity proof signature verification failed",
      "category": "identity",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_IDENTITY_KEY_UNKNOWN",
      "http_status": 401,
      "title": "Identity Key Unknown",
      "description": "Key ID not found in agent key directory",
      "category": "identity",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_IDENTITY_KEY_EXPIRED",
      "http_status": 401,
      "title": "Identity Key Expired",
      "description": "Agent signing key has expired per directory metadata",
      "category": "identity",
      "retryable": false,
      "next_action": "refresh_attestation"
    },
    {
      "code": "E_IDENTITY_KEY_REVOKED",
      "http_status": 401,
      "title": "Identity Key Revoked",
      "description": "Agent signing key has been explicitly revoked",
      "category": "identity",
      "retryable": false,
      "next_action": "refresh_attestation"
    },
    {
      "code": "E_IDENTITY_BINDING_MISMATCH",
      "http_status": 400,
      "title": "Identity Binding Mismatch",
      "description": "Identity binding does not match the request being verified",
      "category": "identity",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_IDENTITY_BINDING_STALE",
      "http_status": 401,
      "title": "Identity Binding Stale",
      "description": "Identity binding is too old and requires fresh binding",
      "category": "identity",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_IDENTITY_BINDING_FUTURE",
      "http_status": 400,
      "title": "Identity Binding Future",
      "description": "Identity binding signed_at timestamp is in the future",
      "category": "identity",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_IDENTITY_PROOF_UNSUPPORTED",
      "http_status": 400,
      "title": "Identity Proof Unsupported",
      "description": "Agent identity proof method is not supported",
      "category": "identity",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_IDENTITY_DIRECTORY_UNAVAILABLE",
      "http_status": 503,
      "title": "Identity Directory Unavailable",
      "description": "Failed to fetch agent key directory",
      "category": "identity",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_MVIS_INCOMPLETE",
      "http_status": 400,
      "title": "MVIS Incomplete",
      "description": "Identity receipt missing one or more Minimum Viable Identity Set required fields (issuer, subject, key_binding, time_bounds, replay_protection)",
      "category": "identity",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_ATTRIBUTION_MISSING_SOURCES",
      "http_status": 400,
      "title": "Attribution Missing Sources",
      "description": "Attribution attestation has empty sources array",
      "category": "attribution",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_ATTRIBUTION_INVALID_FORMAT",
      "http_status": 400,
      "title": "Attribution Invalid Format",
      "description": "Attribution attestation does not conform to schema",
      "category": "attribution",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_ATTRIBUTION_INVALID_REF",
      "http_status": 400,
      "title": "Attribution Invalid Reference",
      "description": "Receipt reference format is invalid (must be jti:{id}, URL, or URN)",
      "category": "attribution",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_ATTRIBUTION_HASH_INVALID",
      "http_status": 400,
      "title": "Attribution Hash Invalid",
      "description": "Content hash structure is invalid (wrong algorithm, encoding, or value length)",
      "category": "attribution",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_ATTRIBUTION_UNKNOWN_USAGE",
      "http_status": 400,
      "title": "Attribution Unknown Usage",
      "description": "Attribution usage type is not recognized",
      "category": "attribution",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_ATTRIBUTION_INVALID_WEIGHT",
      "http_status": 400,
      "title": "Attribution Invalid Weight",
      "description": "Attribution weight is out of valid range (must be 0.0-1.0)",
      "category": "attribution",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_ATTRIBUTION_CIRCULAR_CHAIN",
      "http_status": 400,
      "title": "Attribution Circular Chain",
      "description": "Circular reference detected in attribution chain",
      "category": "attribution",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_ATTRIBUTION_CHAIN_TOO_DEEP",
      "http_status": 400,
      "title": "Attribution Chain Too Deep",
      "description": "Attribution chain exceeds maximum allowed depth (8)",
      "category": "attribution",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_ATTRIBUTION_TOO_MANY_SOURCES",
      "http_status": 400,
      "title": "Attribution Too Many Sources",
      "description": "Attribution has too many sources (maximum 100)",
      "category": "attribution",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_ATTRIBUTION_SIZE_EXCEEDED",
      "http_status": 400,
      "title": "Attribution Size Exceeded",
      "description": "Attribution attestation exceeds maximum size (64KB)",
      "category": "attribution",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_ATTRIBUTION_RESOLUTION_FAILED",
      "http_status": 502,
      "title": "Attribution Resolution Failed",
      "description": "Failed to resolve receipt reference in attribution chain",
      "category": "attribution",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_ATTRIBUTION_RESOLUTION_TIMEOUT",
      "http_status": 504,
      "title": "Attribution Resolution Timeout",
      "description": "Timeout while resolving receipt reference in attribution chain",
      "category": "attribution",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_ATTRIBUTION_NOT_YET_VALID",
      "http_status": 401,
      "title": "Attribution Not Yet Valid",
      "description": "Attribution attestation issued_at time is in the future",
      "category": "attribution",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_ATTRIBUTION_EXPIRED",
      "http_status": 401,
      "title": "Attribution Expired",
      "description": "Attribution attestation has exceeded its expiration time",
      "category": "attribution",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_DISPUTE_INVALID_FORMAT",
      "http_status": 400,
      "title": "Dispute Invalid Format",
      "description": "Dispute attestation does not conform to schema",
      "category": "dispute",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_DISPUTE_INVALID_ID",
      "http_status": 400,
      "title": "Dispute Invalid ID",
      "description": "Dispute ID is not a valid ULID format (26 uppercase alphanumeric characters)",
      "category": "dispute",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_DISPUTE_INVALID_TYPE",
      "http_status": 400,
      "title": "Dispute Invalid Type",
      "description": "Dispute type is not recognized",
      "category": "dispute",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_DISPUTE_INVALID_TARGET_TYPE",
      "http_status": 400,
      "title": "Dispute Invalid Target Type",
      "description": "Dispute target type is not recognized (must be receipt, attribution, identity, or policy)",
      "category": "dispute",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_DISPUTE_INVALID_GROUNDS",
      "http_status": 400,
      "title": "Dispute Invalid Grounds",
      "description": "Dispute grounds code is not recognized",
      "category": "dispute",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_DISPUTE_INVALID_STATE",
      "http_status": 400,
      "title": "Dispute Invalid State",
      "description": "Dispute state is not recognized",
      "category": "dispute",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_DISPUTE_INVALID_TRANSITION",
      "http_status": 400,
      "title": "Dispute Invalid Transition",
      "description": "Invalid state transition for dispute lifecycle",
      "category": "dispute",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_DISPUTE_MISSING_RESOLUTION",
      "http_status": 400,
      "title": "Dispute Missing Resolution",
      "description": "Resolution is required for terminal states (resolved, rejected, final)",
      "category": "dispute",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_DISPUTE_RESOLUTION_NOT_ALLOWED",
      "http_status": 400,
      "title": "Dispute Resolution Not Allowed",
      "description": "Resolution is only valid for terminal states",
      "category": "dispute",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_DISPUTE_NOT_YET_VALID",
      "http_status": 401,
      "title": "Dispute Not Yet Valid",
      "description": "Dispute attestation issued_at time is in the future",
      "category": "dispute",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_DISPUTE_EXPIRED",
      "http_status": 401,
      "title": "Dispute Expired",
      "description": "Dispute attestation has exceeded its expiration time",
      "category": "dispute",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_DISPUTE_OTHER_REQUIRES_DESCRIPTION",
      "http_status": 400,
      "title": "Dispute Other Requires Description",
      "description": "Dispute type 'other' requires description of at least 50 characters",
      "category": "dispute",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_DISPUTE_DUPLICATE",
      "http_status": 409,
      "title": "Dispute Duplicate",
      "description": "A dispute with this ID already exists",
      "category": "dispute",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_DISPUTE_TARGET_NOT_FOUND",
      "http_status": 404,
      "title": "Dispute Target Not Found",
      "description": "The target receipt, attribution, or identity being disputed was not found",
      "category": "dispute",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_BUNDLE_INVALID_FORMAT",
      "http_status": 400,
      "title": "Bundle Invalid Format",
      "description": "Bundle archive structure is invalid (not a valid ZIP or missing required files)",
      "category": "bundle",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_BUNDLE_MANIFEST_MISSING",
      "http_status": 400,
      "title": "Bundle Manifest Missing",
      "description": "manifest.json not found at bundle archive root",
      "category": "bundle",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_BUNDLE_MANIFEST_INVALID",
      "http_status": 400,
      "title": "Bundle Manifest Invalid",
      "description": "manifest.json does not conform to schema or contains invalid values",
      "category": "bundle",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_BUNDLE_HASH_MISMATCH",
      "http_status": 400,
      "title": "Bundle Hash Mismatch",
      "description": "File hash does not match value declared in manifest.json",
      "category": "bundle",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_BUNDLE_SIGNATURE_INVALID",
      "http_status": 400,
      "title": "Bundle Signature Invalid",
      "description": "bundle.sig JWS verification failed over manifest hash",
      "category": "bundle",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_BUNDLE_RECEIPTS_UNORDERED",
      "http_status": 400,
      "title": "Bundle Receipts Unordered",
      "description": "receipts.ndjson is not in deterministic order (issued_at, receipt_id, receipt_hash)",
      "category": "bundle",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_BUNDLE_POLICY_HASH_MISMATCH",
      "http_status": 400,
      "title": "Bundle Policy Hash Mismatch",
      "description": "Policy snapshot hash does not match policy used to evaluate receipts",
      "category": "bundle",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_BUNDLE_KEY_MISSING",
      "http_status": 400,
      "title": "Bundle Key Missing",
      "description": "Required signing key not found in bundle (offline verification mode)",
      "category": "bundle",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_BUNDLE_TIME_RANGE_INVALID",
      "http_status": 400,
      "title": "Bundle Time Range Invalid",
      "description": "Receipt issued_at is outside the bundle declared time_range",
      "category": "bundle",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_BUNDLE_MISSING_RECEIPTS",
      "http_status": 400,
      "title": "Bundle Missing Receipts",
      "description": "No receipts provided when creating bundle",
      "category": "bundle",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_BUNDLE_MISSING_KEYS",
      "http_status": 400,
      "title": "Bundle Missing Keys",
      "description": "No verification keys provided in bundle JWKS",
      "category": "bundle",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_BUNDLE_RECEIPT_INVALID",
      "http_status": 400,
      "title": "Bundle Receipt Invalid",
      "description": "Receipt JWS in bundle is malformed or missing required claims",
      "category": "bundle",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_BUNDLE_DUPLICATE_RECEIPT",
      "http_status": 400,
      "title": "Bundle Duplicate Receipt",
      "description": "Bundle contains multiple receipts with the same ID",
      "category": "bundle",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_BUNDLE_PATH_TRAVERSAL",
      "http_status": 400,
      "title": "Bundle Path Traversal",
      "description": "Bundle contains path traversal attack (zip-slip vulnerability)",
      "category": "bundle",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_BUNDLE_SIZE_EXCEEDED",
      "http_status": 400,
      "title": "Bundle Size Exceeded",
      "description": "Bundle exceeds size limits (entry count, entry size, or total size)",
      "category": "bundle",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_UCP_SIGNATURE_MISSING",
      "http_status": 400,
      "title": "UCP Signature Missing",
      "description": "Request-Signature header is missing from UCP webhook request",
      "category": "ucp",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_UCP_SIGNATURE_MALFORMED",
      "http_status": 400,
      "title": "UCP Signature Malformed",
      "description": "Request-Signature header is not a valid detached JWS (RFC 7797)",
      "category": "ucp",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_UCP_SIGNATURE_ALGORITHM_UNSUPPORTED",
      "http_status": 400,
      "title": "UCP Signature Algorithm Unsupported",
      "description": "Signature algorithm is not ES256, ES384, or ES512",
      "category": "ucp",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_UCP_SIGNATURE_B64_INVALID",
      "http_status": 400,
      "title": "UCP Signature b64 Invalid",
      "description": "b64=false requires 'b64' in 'crit' array per RFC 7797",
      "category": "ucp",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_UCP_KEY_NOT_FOUND",
      "http_status": 401,
      "title": "UCP Key Not Found",
      "description": "Key ID from signature not found in business UCP profile",
      "category": "ucp",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_UCP_KEY_ALGORITHM_MISMATCH",
      "http_status": 401,
      "title": "UCP Key Algorithm Mismatch",
      "description": "Key type is not EC as required for ECDSA signatures",
      "category": "ucp",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_UCP_KEY_CURVE_MISMATCH",
      "http_status": 401,
      "title": "UCP Key Curve Mismatch",
      "description": "Key curve does not match signature algorithm (ES256=P-256, ES384=P-384, ES512=P-521)",
      "category": "ucp",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_UCP_SIGNATURE_INVALID",
      "http_status": 401,
      "title": "UCP Signature Invalid",
      "description": "Webhook signature verification failed against payload",
      "category": "ucp",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_UCP_VERIFICATION_FAILED",
      "http_status": 401,
      "title": "UCP Verification Failed",
      "description": "All verification attempts failed (raw and JCS canonicalized)",
      "category": "ucp",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_UCP_PROFILE_FETCH_FAILED",
      "http_status": 502,
      "title": "UCP Profile Fetch Failed",
      "description": "Failed to fetch business UCP profile from /.well-known/ucp",
      "category": "ucp",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_UCP_PROFILE_INVALID",
      "http_status": 502,
      "title": "UCP Profile Invalid",
      "description": "Business UCP profile does not conform to expected schema",
      "category": "ucp",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_UCP_PROFILE_NO_SIGNING_KEYS",
      "http_status": 502,
      "title": "UCP Profile No Signing Keys",
      "description": "Business UCP profile has empty or missing signing_keys array",
      "category": "ucp",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_UCP_PAYLOAD_EMPTY",
      "http_status": 400,
      "title": "UCP Payload Empty",
      "description": "Webhook request body is empty",
      "category": "ucp",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_UCP_PAYLOAD_NOT_JSON",
      "http_status": 400,
      "title": "UCP Payload Not JSON",
      "description": "Webhook request body is not valid JSON",
      "category": "ucp",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_UCP_PAYLOAD_TOO_LARGE",
      "http_status": 400,
      "title": "UCP Payload Too Large",
      "description": "Webhook request body exceeds maximum allowed size",
      "category": "ucp",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_UCP_ORDER_INVALID",
      "http_status": 400,
      "title": "UCP Order Invalid",
      "description": "UCP order object does not conform to expected schema",
      "category": "ucp",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_UCP_ORDER_MISSING_ID",
      "http_status": 400,
      "title": "UCP Order Missing ID",
      "description": "UCP order is missing required id field",
      "category": "ucp",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_UCP_ORDER_MISSING_LINE_ITEMS",
      "http_status": 400,
      "title": "UCP Order Missing Line Items",
      "description": "UCP order is missing required line_items array",
      "category": "ucp",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_UCP_ORDER_MISSING_TOTALS",
      "http_status": 400,
      "title": "UCP Order Missing Totals",
      "description": "UCP order is missing required totals array or total entry",
      "category": "ucp",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_UCP_EVIDENCE_SERIALIZATION_FAILED",
      "http_status": 500,
      "title": "UCP Evidence Serialization Failed",
      "description": "Failed to serialize UCP evidence to YAML format",
      "category": "ucp",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_WORKFLOW_CONTEXT_INVALID",
      "http_status": 400,
      "title": "Invalid Workflow Context",
      "description": "Workflow context does not conform to WorkflowContextSchema",
      "category": "workflow",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_WORKFLOW_DAG_INVALID",
      "http_status": 400,
      "title": "Invalid Workflow DAG",
      "description": "Workflow DAG semantics violated (self-parent, duplicate parents, or cycle detected)",
      "category": "workflow",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_WORKFLOW_LIMIT_EXCEEDED",
      "http_status": 400,
      "title": "Workflow Limit Exceeded",
      "description": "Workflow exceeds defined limits (parent count, ID length, etc.)",
      "category": "workflow",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_WORKFLOW_ID_INVALID",
      "http_status": 400,
      "title": "Invalid Workflow ID",
      "description": "Workflow ID does not match required format (wf_{ulid|uuid})",
      "category": "workflow",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_WORKFLOW_STEP_ID_INVALID",
      "http_status": 400,
      "title": "Invalid Step ID",
      "description": "Step ID does not match required format (step_{ulid|uuid})",
      "category": "workflow",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_WORKFLOW_PARENT_NOT_FOUND",
      "http_status": 400,
      "title": "Parent Step Not Found",
      "description": "Referenced parent step ID does not exist in the workflow",
      "category": "workflow",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_WORKFLOW_SUMMARY_INVALID",
      "http_status": 400,
      "title": "Invalid Workflow Summary",
      "description": "Workflow summary attestation does not conform to schema",
      "category": "workflow",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_WORKFLOW_CYCLE_DETECTED",
      "http_status": 400,
      "title": "Workflow Cycle Detected",
      "description": "Workflow DAG contains a cycle (not acyclic)",
      "category": "workflow",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INTERACTION_INVALID_FORMAT",
      "http_status": 400,
      "title": "Interaction Invalid Format",
      "description": "Interaction evidence does not conform to InteractionEvidenceV01 schema",
      "category": "interaction",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INTERACTION_MISSING_ID",
      "http_status": 400,
      "title": "Interaction Missing ID",
      "description": "Interaction evidence is missing required interaction_id field",
      "category": "interaction",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INTERACTION_MISSING_KIND",
      "http_status": 400,
      "title": "Interaction Missing Kind",
      "description": "Interaction evidence is missing required kind field",
      "category": "interaction",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INTERACTION_INVALID_KIND_FORMAT",
      "http_status": 400,
      "title": "Interaction Invalid Kind Format",
      "description": "Interaction kind does not match required format (lowercase, 2-128 chars, starts with letter)",
      "category": "interaction",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INTERACTION_KIND_RESERVED",
      "http_status": 400,
      "title": "Interaction Kind Reserved",
      "description": "Interaction kind uses reserved prefix (peac.*, org.peacprotocol.*) but is not in the well-known registry",
      "category": "interaction",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INTERACTION_MISSING_STARTED_AT",
      "http_status": 400,
      "title": "Interaction Missing Started At",
      "description": "Interaction evidence is missing required started_at field",
      "category": "interaction",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INTERACTION_MISSING_EXECUTOR",
      "http_status": 400,
      "title": "Interaction Missing Executor",
      "description": "Interaction evidence is missing required executor or executor.platform field",
      "category": "interaction",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INTERACTION_INVALID_DIGEST",
      "http_status": 400,
      "title": "Interaction Invalid Digest",
      "description": "Digest structure is invalid (wrong value format or missing bytes)",
      "category": "interaction",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INTERACTION_INVALID_DIGEST_ALG",
      "http_status": 400,
      "title": "Interaction Invalid Digest Algorithm",
      "description": "Digest algorithm is not in the canonical set (sha-256, sha-256:trunc-64k, sha-256:trunc-1m)",
      "category": "interaction",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INTERACTION_INVALID_TIMING",
      "http_status": 400,
      "title": "Interaction Invalid Timing",
      "description": "Timing constraint violated (completed_at < started_at or invalid datetime format)",
      "category": "interaction",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INTERACTION_MISSING_RESULT",
      "http_status": 400,
      "title": "Interaction Missing Result",
      "description": "result.status is required when output is present",
      "category": "interaction",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INTERACTION_MISSING_ERROR_DETAIL",
      "http_status": 400,
      "title": "Interaction Missing Error Detail",
      "description": "error_code or extensions required when result.status is error",
      "category": "interaction",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INTERACTION_MISSING_TARGET",
      "http_status": 400,
      "title": "Interaction Missing Target",
      "description": "Kind prefix requires matching target field (tool.* needs tool, http.*/fs.* need resource)",
      "category": "interaction",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INTERACTION_INVALID_EXTENSION_KEY",
      "http_status": 400,
      "title": "Interaction Invalid Extension Key",
      "description": "Extension key does not match required format (reverse-DNS/name[@version])",
      "category": "interaction",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_VERIFY_ISSUER_CONFIG_MISSING",
      "http_status": 502,
      "title": "Issuer Config Missing",
      "description": "peac-issuer.json not found or not fetchable at issuer origin",
      "category": "verifier",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_VERIFY_ISSUER_CONFIG_INVALID",
      "http_status": 502,
      "title": "Issuer Config Invalid",
      "description": "peac-issuer.json is not valid JSON or does not conform to issuer config schema",
      "category": "verifier",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_VERIFY_ISSUER_MISMATCH",
      "http_status": 403,
      "title": "Issuer Mismatch",
      "description": "issuer field in peac-issuer.json does not match the expected issuer origin",
      "category": "verifier",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_VERIFY_JWKS_URI_INVALID",
      "http_status": 502,
      "title": "JWKS URI Invalid",
      "description": "jwks_uri in peac-issuer.json is not a valid HTTPS URL",
      "category": "verifier",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_VERIFY_INSECURE_SCHEME_BLOCKED",
      "http_status": 403,
      "title": "Insecure Scheme Blocked",
      "description": "Non-HTTPS URL encountered during issuer discovery (issuer URL or jwks_uri)",
      "category": "verifier",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_VERIFY_JWKS_INVALID",
      "http_status": 502,
      "title": "JWKS Invalid",
      "description": "JWKS response is not valid JSON or missing required keys array",
      "category": "verifier",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_VERIFY_RECEIPT_TOO_LARGE",
      "http_status": 413,
      "title": "Receipt Too Large",
      "description": "Receipt exceeds maximum size limit (256 KB)",
      "category": "verifier",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_VERIFY_MALFORMED_RECEIPT",
      "http_status": 400,
      "title": "Malformed Receipt",
      "description": "Cannot parse receipt as JWS Compact Serialization",
      "category": "verifier",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_VERIFY_ISSUER_NOT_ALLOWED",
      "http_status": 403,
      "title": "Issuer Not Allowed",
      "description": "Receipt issuer is not in the verifier policy allowlist",
      "category": "verifier",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_VERIFY_KEY_FETCH_BLOCKED",
      "http_status": 403,
      "title": "Key Fetch Blocked",
      "description": "JWKS discovery blocked by SSRF protection (private IP, non-HTTPS, or blocked redirect)",
      "category": "verifier",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_VERIFY_KEY_FETCH_FAILED",
      "http_status": 502,
      "title": "Key Fetch Failed",
      "description": "Network error while fetching JWKS from issuer",
      "category": "verifier",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_VERIFY_KEY_FETCH_TIMEOUT",
      "http_status": 504,
      "title": "Key Fetch Timeout",
      "description": "JWKS discovery timed out (5 second limit)",
      "category": "verifier",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_VERIFY_POINTER_FETCH_BLOCKED",
      "http_status": 403,
      "title": "Pointer Fetch Blocked",
      "description": "Pointer URL fetch blocked by SSRF protection (private IP, non-HTTPS, or blocked redirect)",
      "category": "verifier",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_VERIFY_POINTER_FETCH_FAILED",
      "http_status": 502,
      "title": "Pointer Fetch Failed",
      "description": "Network error while fetching receipt from pointer URL",
      "category": "verifier",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_VERIFY_POINTER_FETCH_TIMEOUT",
      "http_status": 504,
      "title": "Pointer Fetch Timeout",
      "description": "Pointer URL fetch timed out (5 second limit)",
      "category": "verifier",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_VERIFY_POINTER_FETCH_TOO_LARGE",
      "http_status": 413,
      "title": "Pointer Fetch Too Large",
      "description": "Pointer URL response exceeds maximum size limit (256 KB)",
      "category": "verifier",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_VERIFY_POINTER_DIGEST_MISMATCH",
      "http_status": 400,
      "title": "Pointer Digest Mismatch",
      "description": "Fetched receipt SHA-256 digest does not match pointer declaration",
      "category": "verifier",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_VERIFY_JWKS_TOO_LARGE",
      "http_status": 400,
      "title": "JWKS Too Large",
      "description": "JWKS response exceeds maximum size limit (64 KB)",
      "category": "verifier",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_VERIFY_JWKS_TOO_MANY_KEYS",
      "http_status": 400,
      "title": "JWKS Too Many Keys",
      "description": "JWKS contains more than maximum allowed keys (20)",
      "category": "verifier",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_VERIFY_SCHEMA_INVALID",
      "http_status": 400,
      "title": "Schema Invalid",
      "description": "Receipt claims do not conform to expected schema",
      "category": "verifier",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_VERIFY_POLICY_VIOLATION",
      "http_status": 403,
      "title": "Policy Violation",
      "description": "Receipt violates verifier trust policy",
      "category": "verifier",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_VERIFY_INVALID_TRANSPORT",
      "http_status": 400,
      "title": "Invalid Transport",
      "description": "Multiple PEAC-Receipt or PEAC-Receipt-Pointer headers detected (ambiguous transport)",
      "category": "verifier",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_VERIFY_EXTENSION_TOO_LARGE",
      "http_status": 400,
      "title": "Extension Too Large",
      "description": "Receipt extension data exceeds maximum size limit (64 KB)",
      "category": "verifier",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_PARSE_INVALID_INPUT",
      "http_status": 400,
      "title": "Parse Invalid Input",
      "description": "Input to receipt parser is not a non-null object",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_PARSE_COMMERCE_INVALID",
      "http_status": 400,
      "title": "Commerce Receipt Invalid",
      "description": "Receipt has commerce fields (amt/cur/payment) but fails commerce schema validation",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_PARSE_ATTESTATION_INVALID",
      "http_status": 400,
      "title": "Attestation Receipt Invalid",
      "description": "Receipt classified as attestation but fails attestation schema validation",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_CONSTRAINT_VIOLATION",
      "http_status": 400,
      "title": "Kernel Constraint Violation",
      "description": "Receipt claims exceed a kernel constraint (max keys, max depth, max string length, max evidence bytes, or similar structural limit)",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_INVALID_KIND",
      "http_status": 400,
      "title": "Invalid Kind",
      "description": "Wire 0.2 receipt kind field is missing or not one of the accepted structural kinds (evidence, challenge)",
      "category": "validation",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_INVALID_TYPE",
      "http_status": 400,
      "title": "Invalid Type",
      "description": "Wire 0.2 receipt type field is missing or does not conform to the required grammar (reverse-DNS or absolute URI)",
      "category": "validation",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_INVALID_PILLAR_VALUE",
      "http_status": 400,
      "title": "Invalid Pillar Value",
      "description": "Wire 0.2 pillars array contains an unrecognized pillar value outside the closed 10-value taxonomy",
      "category": "validation",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_PILLARS_NOT_SORTED",
      "http_status": 400,
      "title": "Pillars Not Sorted",
      "description": "Wire 0.2 pillars array is not in ascending lexicographic order or contains duplicates",
      "category": "validation",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_ISS_NOT_CANONICAL",
      "http_status": 400,
      "title": "Issuer Not Canonical",
      "description": "Wire 0.2 iss claim does not conform to canonical form: must be an https:// ASCII origin (no default port, no path) or a did: identifier",
      "category": "validation",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_OCCURRED_AT_ON_CHALLENGE",
      "http_status": 400,
      "title": "occurred_at on Challenge",
      "description": "Wire 0.2 occurred_at field is present on a challenge-kind receipt; occurred_at is only permitted on evidence-kind receipts",
      "category": "validation",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_OCCURRED_AT_FUTURE",
      "http_status": 400,
      "title": "occurred_at in Future",
      "description": "Wire 0.2 occurred_at is more than the tolerance window ahead of the current time; the timestamp appears to be in the future",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_JWS_EMBEDDED_KEY",
      "http_status": 400,
      "title": "JWS Embedded Key Rejected",
      "description": "JWS header contains an embedded key (jwk, x5c, x5u, or jku); embedded key material is rejected by the PEAC JOSE hardening rules",
      "category": "cryptography",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_JWS_CRIT_REJECTED",
      "http_status": 400,
      "title": "JWS crit Header Rejected",
      "description": "JWS header contains a crit field; critical header extensions are not supported and are rejected",
      "category": "cryptography",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_JWS_MISSING_KID",
      "http_status": 400,
      "title": "JWS kid Missing or Invalid",
      "description": "JWS header kid field is absent, empty, or exceeds the maximum allowed length (256 characters)",
      "category": "cryptography",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_JWS_B64_REJECTED",
      "http_status": 400,
      "title": "JWS b64:false Rejected",
      "description": "JWS header contains b64:false (RFC 7797 unencoded payload); unencoded payloads are not supported",
      "category": "cryptography",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_JWS_ZIP_REJECTED",
      "http_status": 400,
      "title": "JWS zip Header Rejected",
      "description": "JWS header contains a zip compression field; payload compression is not supported",
      "category": "cryptography",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_UNSUPPORTED_WIRE_VERSION",
      "http_status": 400,
      "title": "Unsupported Wire Version",
      "description": "Receipt peac_version field specifies a wire version that is not supported by this implementation",
      "category": "validation",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_WIRE_VERSION_MISMATCH",
      "http_status": 400,
      "title": "Wire Version Mismatch",
      "description": "JWS header typ value and peac_version payload claim indicate different wire versions; the receipt is incoherent",
      "category": "validation",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_POLICY_BINDING_FAILED",
      "http_status": 400,
      "title": "Policy Binding Failed",
      "description": "Wire 0.2 policy.digest does not match the computed digest of the provided policy document",
      "category": "validation",
      "retryable": false,
      "next_action": "none"
    },
    {
      "code": "E_EAT_SIZE_EXCEEDED",
      "http_status": 400,
      "title": "EAT Size Exceeded",
      "description": "EAT token exceeds the 64 KB size limit enforced before CBOR decode",
      "category": "validation",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_EAT_INVALID_CBOR",
      "http_status": 400,
      "title": "EAT Invalid CBOR",
      "description": "EAT token is not valid CBOR or the payload is not a CBOR map",
      "category": "validation",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_EAT_INVALID_COSE",
      "http_status": 400,
      "title": "EAT Invalid COSE",
      "description": "EAT token is not a valid COSE_Sign1 structure per RFC 9052 Section 4.2",
      "category": "validation",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_EAT_SIGNATURE_FAILED",
      "http_status": 400,
      "title": "EAT Signature Failed",
      "description": "COSE_Sign1 Ed25519 signature verification failed over the Sig_structure",
      "category": "verification",
      "retryable": false,
      "next_action": "retry_with_different_key"
    },
    {
      "code": "E_EAT_UNSUPPORTED_ALG",
      "http_status": 400,
      "title": "EAT Unsupported Algorithm",
      "description": "COSE_Sign1 uses an unsupported algorithm; only EdDSA (alg: -8) is supported",
      "category": "validation",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_EXTENSION_SIZE_EXCEEDED",
      "http_status": 400,
      "title": "Extension Size Exceeded",
      "description": "Extension group or total extensions record exceeds the normative byte-budget limit (EXTENSION_BUDGET)",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_EXTENSION_NON_JSON_VALUE",
      "http_status": 400,
      "title": "Extension Non-JSON Value",
      "description": "Extension group value is not a plain JSON value; functions, Symbols, BigInt, Date, RegExp, Map, Set, objects with toJSON(), and other non-JSON types are rejected",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_EXTENSION_GROUP_REQUIRED",
      "http_status": 400,
      "title": "Extension Group Required",
      "description": "Registered receipt type has a mapped extension group, but that group is absent from the extensions record",
      "category": "verification",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_EXTENSION_GROUP_MISMATCH",
      "http_status": 400,
      "title": "Extension Group Mismatch",
      "description": "Registered receipt type has a mapped extension group, but a different registered first-party extension group is present while the expected one is absent",
      "category": "verification",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_DID_RESOLUTION_FAILED",
      "http_status": 502,
      "title": "DID Resolution Failed",
      "description": "Failed to resolve DID document for key discovery",
      "category": "infrastructure",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_DID_DOCUMENT_INVALID",
      "http_status": 400,
      "title": "Invalid DID Document",
      "description": "DID document does not conform to W3C DID Core v1.0",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_DID_KEY_NOT_FOUND",
      "http_status": 400,
      "title": "DID Verification Key Not Found",
      "description": "No suitable Ed25519 verification key found in DID document",
      "category": "verification",
      "retryable": false,
      "next_action": "retry_with_different_key"
    },
    {
      "code": "E_DID_UNSUPPORTED_METHOD",
      "http_status": 400,
      "title": "Unsupported DID Method",
      "description": "DID method is not supported by the configured resolver",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_DID_DEACTIVATED",
      "http_status": 400,
      "title": "DID Deactivated",
      "description": "DID document has been deactivated",
      "category": "verification",
      "retryable": false,
      "next_action": "abort"
    },
    {
      "code": "E_DID_KEY_AMBIGUOUS",
      "http_status": 400,
      "title": "DID Key Ambiguous",
      "description": "Multiple eligible Ed25519 verification keys found without explicit key selection",
      "category": "verification",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_PKCE_INVALID_VERIFIER",
      "http_status": 400,
      "title": "Invalid PKCE Verifier",
      "description": "PKCE code verifier does not meet RFC 7636 requirements",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_PKCE_CHALLENGE_MISMATCH",
      "http_status": 400,
      "title": "PKCE Challenge Mismatch",
      "description": "PKCE code challenge does not match the code verifier",
      "category": "verification",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_X402_V2_INVALID_FORMAT",
      "http_status": 400,
      "title": "Invalid x402 V2 Format",
      "description": "x402 V2 payload does not conform to expected V2 schema",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_X402_VERSION_UNSUPPORTED",
      "http_status": 400,
      "title": "x402 Version Unsupported",
      "description": "x402 protocol version is not supported by this adapter",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_RECEIPT_URL_RESOLUTION_FAILED",
      "http_status": 502,
      "title": "Receipt URL Resolution Failed",
      "description": "Failed to resolve receipt from receipt_url locator hint",
      "category": "infrastructure",
      "retryable": true,
      "next_action": "retry_after_delay"
    },
    {
      "code": "E_GRPC_METADATA_TOO_LARGE",
      "http_status": 400,
      "title": "gRPC Metadata Too Large",
      "description": "gRPC metadata value exceeds the per-key or aggregate size limit",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_IJSON_DUPLICATE_MEMBER_NAME",
      "http_status": 400,
      "title": "Duplicate JSON Member Name",
      "description": "A JSON object contained duplicate member names, violating I-JSON (RFC 7493)",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_IJSON_NUMBER_OUT_OF_RANGE",
      "http_status": 400,
      "title": "Number Out Of I-JSON Range",
      "description": "A JSON number was non-finite or its magnitude exceeded the I-JSON safe-integer range; encode large values as strings",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    },
    {
      "code": "E_IJSON_INVALID_STRING",
      "http_status": 400,
      "title": "Invalid JSON String",
      "description": "A JSON string contained an invalid escape, lone surrogate, Unicode noncharacter, or invalid UTF-8, violating I-JSON (RFC 7493)",
      "category": "validation",
      "retryable": false,
      "next_action": "retry_with_different_input"
    }
  ]
}