Create Agreement with adding labels and signature on a perticular position using API

Hi, 

I know we can create an agreement using adobe web portal where we are allowed to add the label and the multiple signatures on a specific position on a particular page. I want to do the same process using api for creating Agreement.

Through API I want to allow a specific signer to sign at a position. like If I have 2 signers for a agreement an If I want both signers to sign in different different locations and on one signer's location I don't want to allow other signer to sign. Then How can I do the same through api.