{
  "type": "ZkVmReceipt",
  "system": "risc0",
  "receiptFormat": "groth16-bn254",
  "imageId": "sha256:a1a0bc89b5b1febaeda3519f6dbade0fa5ac16beeb143c4e1b01689573567bc6",
  "seal": "KLktgDoC5wYdCCSTYfcyOZkwtjYW2Lmlw5Kb9dobDCkRl+vsbKbpaotAwcoHGHRZBy2Odosz4LDFO1S/0O3wNBsEgIXvRbO1gbYCqmWy+kaJ7oY6Fkg9RWzxukmIz8HNI7C+4sPpAmOnBMHDpd4BjArNKGVYA4S3txT87pi820QYoe63MA6Jwy3BjRs2yHgNbV1mm7HhKVGkvEdbqAY1NRy8CPhxhMLgK1EgAcjGJ4MfnO4mBh4d9zS1/IomZJWzBQZg/iuivxzrW8efwNfTV8cv0CW+dmLA/wKsLSJ/YDMBIWup+mNGCDDfPf2mI2y3F37ygmTuzwp8LBWdFghavA==",
  "journal": {
    "chaingraph_version": "0.4.0",
    "kernel_digest": "sha256:3f1c6d1e5f697c7965be668eb206a5c9d533b097a4d381c90c48aefaafdf0f91",
    "output": {
      "chain_errors": [],
      "chain_valid": null,
      "chain_verified_by": null,
      "fence": "This node never accepts or handles private key material and never itself runs an Ed25519 verify. signature_valid/chain_valid are the CALLER's own verification claim, asserted and digested into this receipt, never independently re-derived. head_hash is the one field this node DOES independently recompute (pure SHA-256 over the caller-supplied head, never trusted as a caller-asserted value).",
      "head_hash": null,
      "is_genesis": false,
      "not_proven": [
        {
          "detail": "signature_valid and chain_valid are the CALLER's own verification claim (e.g. from running _head.mjs's verifyHeadProof/verifyChain, or chaingraph/standard/head-commit.test.mjs, off-node before calling this node), asserted and digested into this receipt -- exactly like art-562's stage-reference citations. This node does not itself execute Ed25519 verification (the real zkVM guest has no WebCrypto at all; an in-kernel verify() result would not be reproducible across this repo's required execution environments).",
          "item": "Signature / chain verification"
        },
        {
          "detail": "A head-file tip proves the signer's claimed validation-history tip at this seq; it does not itself detect the same signer publishing a different, conflicting head for the same (stream, seq) elsewhere. That needs the ocg-head-tlog@1 witness backing (a later WU), not this node.",
          "item": "Equivocation detection"
        },
        {
          "detail": "This node publishes one head-commit event. Whether a model's revalidation is overdue is computed separately by art-453-model-validation-status (next_due_in_days); this stream only makes that history citable in sequence order.",
          "item": "Revalidation-cadence enforcement"
        },
        {
          "detail": "root is a caller-supplied execution_hash citing the period's art-562 lineage pack (or bare art-453/art-489 receipt), asserted and digested into this receipt. This node performs no lookup against a live artifact store and does not itself verify that the cited hash corresponds to a real, still-valid upstream artifact.",
          "item": "Root-artifact authenticity"
        },
        {
          "detail": "This receipt evidences one head-commit publication event. It has no bearing on whether the underlying model is fit for use and does not itself satisfy RDARR, BCBS 239, or SR 26-2 -- those are firm-level governance obligations this document evidences a piece of, never fulfills.",
          "item": "RDARR / BCBS 239 / SR 26-2 compliance"
        }
      ],
      "prev_head_hash": null,
      "regulatory_framework": "SPEC.md §HEAD-1 (this estate's own head-commit primitive, PROV-HEAD-1, DONE/merged) applied to a model's SR 26-2 revalidation-history stream; not itself an RDARR, BCBS 239, or SR 26-2 requirement.",
      "root": null,
      "rotates_to": null,
      "seq": null,
      "signature_valid": null,
      "signature_verified_by": null,
      "signer": null,
      "stream": null,
      "structural_error": "head is required.",
      "timestamp": null
    }
  }
}