GPTs with actions calling external APIs

Hi there,

I am exploring an enterprise use case for GPTs. We have multiple actions/databases that could get connected to GPTs. I was wondering if anyone has tried creating OpenAI GPTs by calling external APIs or databases where:
(a) number of API endpoints are 10-30
(b) single API returns >100K tokens
(c) single API returns a complicated JSON that needs to be further decoded

Best wishes,