> The source_name field on Orders should be what you need.
How so? Have you read what I wrote?
The source_name field only says only "pos" or "web" or whatever one might set in a custom created order through the API.
But we want the info about the POS device id and its location, in the case of a POS order (that is, when source_name == 'pos'). This info seems conveniently stored only in the undocumented "source_identifier" field like this:
order.source_identifier = `${order.location_id}-${order.pos_device_id}-${order.pos_order_number}`
where the 'pos_device_id' and 'pos_order_number' (the separately incrementing number for orders only from that specific POS device; separate from the global 'order_number' counter) fields are not separately accessable existing fields, but only encoded here and in 'order.name'. They can be extracted unambiguously from here, and only from here (from source_identifier).
They are also encoded in 'order.name', but not in a way that they can be extracted unambiguously without further knowledge.
The 'order.name' field takes the form
order.name = `${order_prefix}${order.pos_device_id}-${order.pos_order_number}${order_suffix}`
The only other way to extract the 'order.pos_device_id' from this one unambiguously is by knowng 'order_prefix' and 'order_suffix' settings of the store (which are not accessible through the API).
So, the problem once again in summary is: It would be good to have a field like 'source_identifier' to rely on to extract this information without ambiguity. The only other place it's stored is in 'order_name', but not in a way that it can be extracted unambiguously.
