When invoking external services from Bizagi, you may easily use the WS Connector to:
•Send files already stored in Bizagi to a Web service.
•Receive files from the response of a Web service and store it automatically in Bizagi.
This means that both of the scenarios above are handled by Bizagi when using the graphical mapping features to configure the invocation to the Web service (set its input and output parameters).
Keep in mind that files in Bizagi are stored either in: File type attributes or Image type attributes of the data model.
Follow the articles below for a configuration example in both scenarios: