{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://veritaschain.org/schema/vcp-event-v1.2.json",
  "title": "VeritasChain Protocol (VCP) Event - Version 1.2",
  "description": "JSON Schema for VCP v1.2 events in the structured Header/Payload/Security encoding. This is the encoding used when a VCP Event is carried as the payload of a SCITT Signed Statement (draft-kamimura-scitt-vcp) and in VCP v1.1+ implementation examples. This schema enforces protocol-level requirements only. Conformance-tier and VC-Certified requirements (for example, mandatory MerkleRoot, MerkleIndex, and AnchorReference under v1.1+ certification, per Specification Section 6.4.1) are Registration Policy and certification matters and are intentionally not enforced here.",
  "$comment": "Maintainer: VeritasChain Standards Organization (VSO). Source specification: https://github.com/veritaschain/vcp-spec/tree/main/spec/v1.2 . License: CC BY 4.0.",
  "type": "object",
  "required": ["Header", "Payload", "Security"],
  "additionalProperties": false,
  "properties": {
    "Header": { "$ref": "#/$defs/Header" },
    "Payload": { "$ref": "#/$defs/Payload" },
    "Security": { "$ref": "#/$defs/Security" },
    "PolicyIdentification": { "$ref": "#/$defs/PolicyIdentification" }
  },
  "if": {
    "required": ["Header"],
    "properties": {
      "Header": {
        "required": ["EventType"],
        "properties": { "EventType": { "const": "ERASURE" } }
      }
    }
  },
  "then": {
    "properties": {
      "Payload": {
        "required": ["VCP-PRIVACY"],
        "properties": {
          "VCP-PRIVACY": {
            "required": [
              "ErasureTargetEventIDs",
              "ErasureReason",
              "KeyDestructionProof",
              "OperatorID"
            ]
          }
        }
      }
    }
  },
  "$defs": {
    "UUID": {
      "type": "string",
      "pattern": "^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$",
      "$comment": "UUIDv7 (RFC 9562) is required for time-sortable EventIDs at Gold/Platinum tiers; the pattern accepts any RFC 9562 UUID."
    },
    "DecimalString": {
      "type": "string",
      "pattern": "^-?[0-9]+(\\.[0-9]+)?$",
      "$comment": "Specification Section 4.2.2: all financial numeric values MUST be encoded as strings to avoid IEEE 754 precision loss under RFC 8785 canonicalization."
    },
    "Header": {
      "type": "object",
      "required": [
        "EventID",
        "TimestampISO",
        "TimestampInt",
        "EventType",
        "ActorID",
        "ChainID",
        "SequenceNum",
        "PolicyID"
      ],
      "additionalProperties": false,
      "properties": {
        "EventID": {
          "$ref": "#/$defs/UUID",
          "description": "Unique event identifier. UUIDv7 (RFC 9562) provides time-sortable identification."
        },
        "TraceID": {
          "$ref": "#/$defs/UUID",
          "description": "OPTIONAL transaction trace identifier (for example, CAT Rule 613 correlation)."
        },
        "TimestampISO": {
          "type": "string",
          "format": "date-time",
          "description": "ISO 8601 / RFC 3339 timestamp, UTC, up to nanosecond precision."
        },
        "TimestampInt": {
          "type": "integer",
          "minimum": 0,
          "description": "Nanoseconds since the Unix epoch (UTC), as a 64-bit integer.",
          "$comment": "Values exceed 2^53; parsers must preserve 64-bit integer precision."
        },
        "EventType": {
          "type": "string",
          "enum": [
            "INIT", "SIG", "ORD", "ACK", "EXE", "CXL", "MOD", "RSK",
            "ERR", "HBT", "CLS", "ANC",
            "ERR_CONN", "ERR_AUTH", "ERR_TIMEOUT", "ERR_REJECT",
            "ERR_PARSE", "ERR_SYNC", "ERR_RISK", "ERR_SYSTEM",
            "ERR_RECOVER",
            "ERASURE"
          ],
          "description": "VCP v1.2 Event Type Registry: core types (v1.0), standardized error types (v1.1), and ERASURE (v1.2)."
        },
        "ActorID": {
          "type": "string",
          "minLength": 1,
          "description": "Identifier of the entity generating this event."
        },
        "ChainID": {
          "type": "string",
          "minLength": 1,
          "description": "Identifier of the per-Actor hash chain."
        },
        "SequenceNum": {
          "type": "integer",
          "minimum": 0,
          "description": "Monotonically increasing sequence number within the Actor's chain."
        },
        "PolicyID": {
          "type": "string",
          "minLength": 1,
          "description": "Registration Policy identifier. SHOULD follow the Issuer Domain + Local ID convention (reverse_domain:local_identifier), for example 'org.veritaschain.policy:gold-v1-2' (Specification Section 5.5.4)."
        },
        "SCITTAlignment": { "$ref": "#/$defs/SCITTAlignment" }
      }
    },
    "SCITTAlignment": {
      "type": "object",
      "description": "OPTIONAL SCITT alignment object (v1.2). REQUIRED under the VCP_SCITT conformance profile; RECOMMENDED under VCP_REGULATORY.",
      "required": ["Version", "ConformanceProfile"],
      "additionalProperties": false,
      "properties": {
        "Version": {
          "type": "string",
          "description": "VCP specification version governing the alignment semantics.",
          "examples": ["1.2"]
        },
        "ConformanceProfile": {
          "type": "string",
          "enum": ["VCP_BASE", "VCP_SCITT", "VCP_REGULATORY"]
        },
        "StatementID": {
          "type": "string",
          "description": "Identifier of the SCITT Signed Statement carrying this event."
        },
        "TransparencyServiceID": {
          "type": "string",
          "description": "Identifier of the Transparency Service with which the event is registered. REQUIRED under the VCP_SCITT profile."
        },
        "ReceiptFormat": {
          "type": "string",
          "description": "Receipt encoding in use.",
          "examples": ["COSE_RECEIPT"]
        },
        "RegistrationPolicy": {
          "type": "object",
          "additionalProperties": false,
          "properties": {
            "PolicyID": { "type": "string" },
            "Issuer": { "type": "string" },
            "IssuedAt": { "type": "integer", "minimum": 0 }
          }
        }
      }
    },
    "Payload": {
      "type": "object",
      "minProperties": 1,
      "description": "Domain data organized into VCP-* modules. Module names MUST match ^VCP-[A-Z]+$.",
      "patternProperties": {
        "^VCP-[A-Z]+$": { "type": "object" }
      },
      "additionalProperties": false,
      "properties": {
        "VCP-TRADE": {
          "type": "object",
          "description": "Trading data: orders, executions, modifications, cancellations.",
          "properties": {
            "OrderID": { "type": "string" },
            "BrokerOrderID": { "type": "string" },
            "ExchangeOrderID": { "type": "string" },
            "Symbol": { "type": "string" },
            "Side": { "type": "string", "enum": ["BUY", "SELL"] },
            "OrderType": {
              "type": "string",
              "enum": ["MARKET", "LIMIT", "STOP", "STOP_LIMIT"]
            },
            "TimeInForce": { "type": "string" },
            "Price": { "$ref": "#/$defs/DecimalString" },
            "Quantity": { "$ref": "#/$defs/DecimalString" },
            "ExecutedQty": { "$ref": "#/$defs/DecimalString" },
            "RemainingQty": { "$ref": "#/$defs/DecimalString" },
            "ExecutionPrice": { "$ref": "#/$defs/DecimalString" },
            "Commission": { "$ref": "#/$defs/DecimalString" },
            "Slippage": { "$ref": "#/$defs/DecimalString" },
            "Currency": {
              "type": "string",
              "description": "ISO 4217 currency code."
            },
            "RejectReason": { "type": "string" },
            "AccountID": {
              "type": "string",
              "description": "MUST be pseudonymized."
            },
            "ClientID": { "type": "string" },
            "VenueID": {
              "type": "string",
              "description": "ISO 10383 MIC code when applicable."
            }
          }
        },
        "VCP-RISK": {
          "type": "object",
          "description": "Risk management data: exposure, limits, margin."
        },
        "VCP-GOV": {
          "type": "object",
          "description": "Governance data: algorithm parameters, decision factors, operator actions.",
          "properties": {
            "AlgoID": { "type": "string" },
            "AlgoVersion": { "type": "string" },
            "AlgoType": {
              "type": "string",
              "enum": ["AI_MODEL", "RULE_BASED", "HYBRID"]
            },
            "ModelHash": { "type": "string" },
            "DecisionFactors": {
              "type": ["array", "object"],
              "description": "Compact form: array of factor names. Extended form: object per Specification Section 5.1.1."
            },
            "ConfidenceScore": {
              "type": ["string", "number"],
              "description": "Confidence in [0.0, 1.0]. String encoding is RECOMMENDED for precision (Specification Section 5.1.1)."
            },
            "RiskCheckPassed": { "type": "boolean" }
          }
        },
        "VCP-PRIVACY": {
          "type": "object",
          "description": "Privacy metadata: encrypted-field inventory, key references, retention policy, and (v1.2) ERASURE event fields.",
          "properties": {
            "EncryptedFields": {
              "type": "array",
              "items": { "type": "string" }
            },
            "KeyID": { "type": "string" },
            "Algorithm": { "type": "string" },
            "RetentionPolicy": { "type": "string" },
            "ErasureTargetEventIDs": {
              "type": "array",
              "minItems": 1,
              "items": { "$ref": "#/$defs/UUID" },
              "description": "Events whose protected fields are crypto-shredded (ERASURE events)."
            },
            "ErasureReason": {
              "type": "string",
              "enum": ["SUBJECT_REQUEST", "RETENTION_EXPIRED", "LEGAL_ORDER"]
            },
            "KeyDestructionProof": {
              "type": "string",
              "description": "Evidence that the DEK was destroyed (for example, an HSM or KMS attestation)."
            },
            "RetentionExemption": {
              "type": "string",
              "description": "Legal basis where a retention obligation overrides erasure (for example, MiFID II Article 16(7))."
            },
            "OperatorID": {
              "type": "string",
              "description": "Actor authorizing the erasure."
            }
          }
        },
        "VCP-XREF": {
          "type": "object",
          "description": "Cross-reference data, including v1.2 multi-actor chain linking."
        },
        "VCP-RECOVERY": {
          "type": "object",
          "description": "Recovery operations, subject to the v1.2 operational constraints."
        }
      }
    },
    "Security": {
      "type": "object",
      "required": ["EventHash", "SignAlgo"],
      "additionalProperties": false,
      "$comment": "VC-Certified v1.1+ additionally requires MerkleRoot, MerkleIndex, and AnchorReference (Specification Section 6.4.1). Those are certification requirements enforced by Registration Policy, not by this protocol-level schema. In the SCITT Signed Statement encoding, the event signature MAY be carried by the COSE_Sign1 envelope, in which case the Signature field is omitted here.",
      "properties": {
        "Version": { "type": "string" },
        "EventHash": {
          "type": "string",
          "minLength": 1,
          "description": "Hash of the canonicalized (RFC 8785) Header and Payload. Production values use the algorithm-prefixed form 'sha256:' followed by 64 lowercase hex characters."
        },
        "PrevHash": {
          "type": "string",
          "description": "OPTIONAL hash of the previous event in this Actor's chain; absent for INIT events."
        },
        "HashAlgo": {
          "type": "string",
          "enum": ["SHA256", "SHA3_256", "BLAKE3", "SHA3_512"]
        },
        "Signature": {
          "type": "string",
          "description": "Base64-encoded signature over the event. MAY be omitted in the SCITT encoding, where COSE_Sign1 carries the signature."
        },
        "SignAlgo": {
          "type": "string",
          "enum": [
            "ED25519",
            "ECDSA_SECP256K1",
            "RSA_2048",
            "DILITHIUM2",
            "FALCON512"
          ],
          "description": "Signature algorithm registry value. ED25519 is the default. DILITHIUM2 (ML-DSA, FIPS 204) and FALCON512 hold EXPERIMENTAL status in v1.2. RSA_2048 is DEPRECATED."
        },
        "PQCSignature": {
          "type": "string",
          "description": "OPTIONAL post-quantum signature for dual-signature deployments (Specification Appendix E)."
        },
        "PQCSignAlgo": {
          "type": "string",
          "description": "Algorithm of PQCSignature.",
          "examples": ["DILITHIUM2", "FALCON512"]
        },
        "MerkleRoot": { "type": "string" },
        "MerkleIndex": { "type": "integer", "minimum": 0 },
        "AnchorRef": {
          "type": "string",
          "description": "Reference to the external anchor location (draft-kamimura-scitt-vcp field name)."
        },
        "AnchorReference": {
          "type": "string",
          "description": "Reference to the anchor record (Specification Section 6.4 field name)."
        }
      }
    },
    "PolicyIdentification": {
      "type": "object",
      "description": "OPTIONAL top-level Policy Identification block (Specification Section 5.5).",
      "required": ["PolicyID", "ConformanceTier"],
      "properties": {
        "Version": { "type": "string" },
        "PolicyID": { "type": "string", "minLength": 1 },
        "ConformanceTier": {
          "type": "string",
          "enum": ["SILVER", "GOLD", "PLATINUM"]
        },
        "RegistrationPolicy": {
          "type": "object",
          "properties": {
            "Issuer": { "type": "string" },
            "PolicyURI": { "type": "string" },
            "EffectiveDate": { "type": "integer" },
            "ExpirationDate": { "type": "integer" }
          }
        },
        "VerificationDepth": {
          "description": "Declares verification capabilities."
        }
      }
    }
  }
}