The Postman API provides programmatic access to your synced data: collections, environments, mock servers, and monitors. You can create collections (that'll instantly be synced to your Postman app), set up monitors or mock servers on those collections, and update any part of these entities.
You'll need an API Key to get started. You can create one in your dashboard - https://app.getpostman.com/dashboard/integrations/pm_pro_api/list. Once you have a key, just follow the reference at https://docs.api.getpostman.com/ to get started!