How do I retrieve a shipper_id for API calls?

I’m using V3 of the API.

Trying to assign weight and shipping method to an order via the API. It seems that I need to assign a “shipper_id” value to the body content, but I don’t know what the shipper_id corresponds to is or how to retrieve it.

Ultimate goal is to be able to use the API to create orders, then set a shipper and shipping method in order to generate labels (all via the API). I’m trying to do this for a UPS order initially, but will eventually need to do this for FedEx and Endicia as well.

Any help is greatly appreciated.

If you use the endpoint found at, it will return all of the shippers for the account with their carrier type as “vendor” and the shipper_id as “id” per shipper.

Thank you - that worked.

However, that endpoint is (I believe) a V2 endpoint (not identified in the V3 documentation I was told to use). How do I know when to use the V2 documentation (and end points) and when to use the V3 documentation (and end points)?

Yes, the clarification between the two is that you will use v3 for all order related calls, and v2 for everything else such as products and settings.