{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "#/components/schemas/ChangeEventMessage",
  "title": "ChangeEventMessage",
  "type": "object",
  "description": "The structure of a Change Data Capture event message as received by subscribers. Contains the event header with change metadata and the changed field values.",
  "properties": {
    "ChangeEventHeader": {
      "type": "object",
      "description": "Header containing metadata about the change",
      "properties": {
        "entityName": {
          "type": "string",
          "description": "The SObject type that changed (e.g., Account)"
        },
        "recordIds": {
          "type": "array",
          "items": {
            "type": "string"
          },
          "description": "Array of record IDs that changed (may be batched)"
        },
        "changeType": {
          "type": "string",
          "enum": [
            "CREATE",
            "UPDATE",
            "DELETE",
            "UNDELETE",
            "GAP_CREATE",
            "GAP_UPDATE",
            "GAP_DELETE",
            "GAP_UNDELETE",
            "GAP_OVERFLOW"
          ],
          "description": "The type of change. GAP_ prefixed types indicate events replayed after a gap in delivery."
        },
        "changeOrigin": {
          "type": "string",
          "description": "The origin of the change (e.g., com/salesforce/api/rest/63.0)"
        },
        "transactionKey": {
          "type": "string",
          "description": "Unique key identifying the transaction that caused the change"
        },
        "sequenceNumber": {
          "type": "integer",
          "description": "Sequence number for ordering within a transaction"
        },
        "commitTimestamp": {
          "type": "integer",
          "description": "Unix timestamp in milliseconds when the change was committed"
        },
        "commitNumber": {
          "type": "integer",
          "description": "System change number for ordering"
        },
        "commitUser": {
          "type": "string",
          "description": "The 18-character ID of the user who made the change"
        },
        "changedFields": {
          "type": "array",
          "items": {
            "type": "string"
          },
          "description": "List of field API names that changed (for UPDATE events)"
        },
        "nulledFields": {
          "type": "array",
          "items": {
            "type": "string"
          },
          "description": "List of field API names that were set to null"
        },
        "diffFields": {
          "type": "array",
          "items": {
            "type": "string"
          },
          "description": "List of fields included in the change event payload"
        }
      }
    }
  },
  "additionalProperties": true
}