How to know server application id or other server info when to use oauth 2.0?

if i want to link two server application to my application through oauth 2.0 , how to distinguish these two server application in my application? it seems i can receive only access token. that’s to say, how to find who is the right seller if the two server applications are on behalf of seller?
is merchart id useful?

With OAuth each seller is uniquely identified by the merchant_id. Each OAuth’d seller will have their own access token that you’ll use to make API calls with. :slightly_smiling_face: