@jmonterr I don't think there is a limitation on license for API's on Cisco DNA Center, at least the basic API's should work to get device details etc which are part of base Automation should work with Essential license, there might be some advanced API's which are related to SD-Access or Assurance which needs Advantage license might not work. The Essential License, you can do base Automation which includes Inventory management, Software Management, PNP etc.,
Hope this helps.
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