{ "$schema":                    "https://json-schema.org/draft/2020-12/schema",
  "$id":                        "https://schemas.mpai.community/PTF/V1.0/data/TrustMessage.json",
  "title":                      "Trust Message V1.0", "description": "A unified structure for Trust Requests and Trust Responses.",
                                "type": "object", "required": ["Header", "MessageType", "MessageID", "MessageTime", "Signature"],
                                "additionalProperties": false, "properties": {

    "Header":                   { "type": "string", "pattern": "^PTF-MSG-V[0-9]{1,2}[.][0-9]{1,2}$" },
    "MInstanceID":              { "type": "string" },
    "MessageID":                { "type": "string", "description": "Unique identifier of the trust message." },
    "MessageTime":              { "$ref": "https://schemas.mpai.community/OSD/V1.5/data/Time.json" },
    "MessageType":              { "type": "string", "enum": ["TrustRequest", "TrustResponse"],
                                  "description": "Indicates whether this message is a request or a response." },

    "RequesterID":              { "type": "string", "description": "Identifier of the entity making the request." },
    "ResponderID":              { "type": "string", "description": "Identifier of the entity responding to the request." },

    "Request":                  { "type": "object", "additionalProperties": false, "properties": {
      "Operation":              { "type": "string", "description": "Requested trust operation." },
      "TargetType":             { "type": "string", "description": "Type of object the request concerns." },
      "TargetID":               { "type": "string", "description": "Identifier of the target object." } } },

    "Response":                 { "type": "object", "additionalProperties": false, "properties": {
      "Status":                 { "type": "string", "enum": ["Success", "Failure"] },
      "Reason":                 { "type": "string", "description": "Optional reason for failure." },
      "Result":                 { "type": "string", "description": "Optional result payload." } } },

    "Signature":                { "type": "object", "required": ["Algorithm", "Value"],
                                  "additionalProperties": false, "properties": {
      "Algorithm":              { "$ref": "https://schemas.mpai.community/PTF/V1.0/data/SecurityAlgorithmTaxonomy.json#/properties/Signature" },
      "Value":                  { "type": "string" } } },

    "DataXMData":               { "$ref": "https://schemas.mpai.community/PTF/V1.0/data/DataExchangeMetadata.json" },
    "DescrMetadata":            { "type": "string", "maxLength": 2048 } },

  "oneOf": [                    { "properties": { "MessageType": { "const": "TrustRequest" },  "Request":  { "type": "object" } },
                                  "required": ["Request", "RequesterID"] },

                                { "properties": { "MessageType": { "const": "TrustResponse" }, "Response": { "type": "object" } },
                                  "required": ["Response", "ResponderID"] } ] }