curl --request GET \
  --url https://api.siftstack.com/api/v1/user-defined-functions/{userDefinedFunctionId} \
  --header 'Authorization: Bearer <token>'

{
  "userDefinedFunction": {
    "userDefinedFunctionId": "<string>",
    "name": "<string>",
    "userDefinedFunctionVersionId": "<string>",
    "version": 123,
    "description": "<string>",
    "changeMessage": "<string>",
    "userNotes": "<string>",
    "expression": "<string>",
    "functionInputs": [
      {
        "identifier": "<string>",
        "dataType": "FUNCTION_DATA_TYPE_UNSPECIFIED",
        "constant": true
      }
    ],
    "functionDependencies": [
      {
        "userDefinedFunctionVersionId": "<string>"
      }
    ],
    "createdDate": "2023-11-07T05:31:56Z",
    "modifiedDate": "2023-11-07T05:31:56Z",
    "createdByUserId": "<string>",
    "modifiedByUserId": "<string>",
    "metadata": [
      {
        "key": {
          "name": "<string>",
          "type": "METADATA_KEY_TYPE_UNSPECIFIED",
          "archivedDate": "2023-11-07T05:31:56Z"
        },
        "stringValue": "<string>",
        "numberValue": 123,
        "booleanValue": true,
        "archivedDate": "2023-11-07T05:31:56Z"
      }
    ],
    "archivedDate": "2023-11-07T05:31:56Z",
    "functionOutputType": "FUNCTION_DATA_TYPE_UNSPECIFIED"
  }
}