{
  "$comment": "A record registered at the public transparency log on 2026-09-13 at 20:57Z, exactly as the log answered, with what a verifier recomputes from it (external-witness.md). The capsule_id is a throwaway SHA-256 (over random bytes), not a chain head; the shape is the one every keeper stores as `external` and the verifier checks. Offline: decode receipt_b64 as COSE_Sign1, take the inclusion proof from the unprotected header (label 396, key -1), rebuild the root from leaf_hash at leaf_index in a tree of tree_size, verify signature with the key under log_key over the Sig_structure with the root bytes as the detached payload. Online (only while the log serves them): /anchor/sth and /anchor/consistency-proof from tree_size to the current tree.",
  "log": "https://witness.agentactioncapsule.org",
  "log_key": {
    "did": "did:web:witness.agentactioncapsule.org",
    "kid": "did:web:witness.agentactioncapsule.org#19a9ab3e02fad55c",
    "kty": "OKP",
    "crv": "Ed25519",
    "x": "ObtlTJ3Ar-HA7e8N7_qmkJm4UYg2ybom4EkVNYQPlrU",
    "pubkey_hex": "39bb654c9dc0afe1c0edef0deffaa69099b8518836c9ba26e0491535840f96b5",
    "key_id": "19a9ab3e02fad55c",
    "key_id_rule": "first 16 hex of SHA-256 over the 32 raw key bytes"
  },
  "request": {
    "method": "POST",
    "path": "/register",
    "body": {
      "capsule_id": "96d9f943bc47fa291131e9be66e6a54b583e55a2b14bbdc08b095776b43a1568"
    }
  },
  "response": {
    "receipt_b64": "0oRPowEnGQGLAQ+hBhpqpw4ioRkBjKEggVjUgxkEtBkEs4ZYIOMgKT/45NGaAu9WcvzGh/tIWDIuroiv2AIvawpbLjyKWCD8jmJ02b12noonaEXNBwYp7F6ccK++ZYiigmFbLVIGL1ggDHGCoKSGd0XnxYWmnt8Kyy7wC+si27xSzcEIRjitNHRYIOQeKCn0U00KpllfedLsryNiWiYDLq3S/pOfjr5WbjJZWCAIZm+A4o325tYJx8mbP7UdgTIIi+t0dbilPJLbo0Ds2Fggnion038V2wSA4dzzA6DgFfper3ko1uQ0tXXaviuYKG/2WEBcwKx5V7ueQfzU+WoLJxUj27eeSNlu7YFzVgP602Y4jQpdM9LVqRUu126uLOD8RDrRTWLB+AaP1iW6tfi+YLQG",
    "entry_hash": "4d962f30d9bc5c210a35d4ed46379c2fb89da067703ecf8b03e46a7387420c3e",
    "entry_hash_scheme": "legacy",
    "leaf_index": 1203,
    "tree_size": 1204
  },
  "expected": {
    "entry_hash": "4d962f30d9bc5c210a35d4ed46379c2fb89da067703ecf8b03e46a7387420c3e",
    "entry_hash_rule": "SHA-256 over the 32 bytes of capsule_id",
    "leaf_hash": "1df1d9c17c0052e4c1bec453aa8d90060c20293a2b15ded00ef3703aa1ac4706",
    "leaf_hash_rule": "SHA-256 over 0x00 || entry_hash bytes (RFC 6962)",
    "receipt": {
      "protected": {
        "1": -8,
        "395": 1,
        "15": {
          "6": 1789333026
        }
      },
      "protected_meaning": "alg EdDSA; verifiable data structure 1 = RFC9162_SHA256; CWT claims with iat",
      "unprotected": {
        "396": {
          "-1": "[cbor([tree_size, leaf_index, [path...]])]"
        }
      },
      "payload": "nil (detached: the root bytes)",
      "tree_size": 1204,
      "leaf_index": 1203,
      "audit_path": [
        "e320293ff8e4d19a02ef5672fcc687fb4858322eae88afd8022f6b0a5b2e3c8a",
        "fc8e6274d9bd769e8a276845cd070629ec5e9c70afbe6588a282615b2d52062f",
        "0c7182a0a4867745e7c585a69edf0acb2ef00beb22dbbc52cdc1084638ad3474",
        "e41e2829f4534d0aa6595f79d2ecaf23625a26032eadd2fe939f8ebe566e3259",
        "08666f80e28df6e6d609c7c99b3fb51d8132088beb7475b8a53c92dba340ecd8",
        "9e2a27d37f15db0480e1dcf303a0e015fa5eaf7928d6e434b575dabe2b98286f"
      ],
      "sig_structure": "cbor([\"Signature1\", protected_bstr, b\"\", root_bytes])"
    },
    "root_hash": "18cd79c698a89e9a64fa27b1fa077dd21dbedf76153fc3ac6b13a37ec36ca2fd",
    "sth_at_that_size": {
      "tree_size": 1204,
      "root_hash": "18cd79c698a89e9a64fa27b1fa077dd21dbedf76153fc3ac6b13a37ec36ca2fd",
      "timestamp": "2026-09-13T20:57:06.797313Z",
      "signature": {
        "signature": "00f0fb59f9571691cb27ac7c77345c6b3fcfe93978e30267440adbb897364668ac33c928788aa11ca87fa1ce13c8d9909abc9a9869f99871feaa120cccd8ba02",
        "key_id": "19a9ab3e02fad55c",
        "alg": "ed25519",
        "created_at": "2026-09-13T20:57:06.797669Z"
      }
    },
    "sth_signature_rule": "Ed25519 over the compact JSON, keys sorted, of {tree_size, root_hash, timestamp} with the timestamp as Python's isoformat (+00:00, not the Z the endpoint prints)"
  }
}