API Gateway setup for multiple vendors

Hello,

We are working on setting up an AWS API Gateway to manage a couple of vendors which will interact with our system. We have a few questions.

  1. Would a machine to machine API be the best here, or should we set up a username and password for them?

  2. If we do machine to machine, is it a single API or one for each? If single, how do we distinguish them?

  3. If we have multiple machine to machine APIs, is it possible to configure API Gateway for that?

Thank you!