GUID Data Type v2
A GUID is a 128-bit identifier used to identify an object with practical global uniqueness.
Author it with Type: guid and use its standard text representation:
RecordId:
Type: guid
Value: "00000000-0000-0000-0000-000000000000"
A GUID Property validates and converts the text representation for the receiving Node Method. A Flowgear object key may look like a GUID, but you should still use the type required by that specific contract. A Connection uses connectionKey, not guid.
See also
See Data Types.