Domec API expose some methods and endpoints which receives a Transaction Receipt objects in the input. The Transaction Receipt object has a metadata parameter. You can use this parameter to attach key-value data coming from your system.
Metadata is useful for storing additional, structured information on an object. As an example, you could store your order unique identifier from your system on a receipt object. Metadata is not used by Domec (e.g., to authorize or decline a charge), and won’t be seen by your users unless you choose to show it to them. Some of the operations listed above also support a description parameter. You can use the description parameter to annotate a charge, for example, with a human-readable description, such as “2 shirts for firstname.lastname@example.org”. Unlike metadata, description is a single string, and your users may see it (e.g., in email receipts Domec sends on your behalf).
Note: The metadata field support up to 4kb of data.