Since calling generate_guid creates a new GUID each time, you need to save it as a variable to use the same one for message processing. To generate a new GUID for multiple fields, you would insert the following script in the Global Inbound Script, or Global Outbound Preprocess Script.

For example:

from ifware import guid

# Generates a 128 bit guid (default).
# For example, '40C76A47C600704CDD457D49AA55B94C.'
guid_str = guid.generate_guid()

Note that guid_str is a variable that holds the GUID. You can then use "guid_str" in any field you want to generate a GUID for by inserting the following code in the inbound or outbound script:

value = guid_str

This means you can generate a GUID for use in multiple fields for the same message, as shown below:

Generating GUIDs for Multiple Fields