@mcaravind we have all metrics and their details documented here.
It’s worth noting though that our best practices for analytics recommend pulling stats with an hour granularity at the line item or promoted tweet level, persisting that data on your side and then rolling that lower-level up into campaign and funding instrument.
Analytics calls in the Ads API use a cost-based rate limiting mechanism and you’ll likely hit rate limits quick if you’re pulling stats at the campaign, account or funding instrument level rather than following our recommended practices.
Related documentation:
https://dev.twitter.com/ads/analytics/metrics-and-segmentation
https://dev.twitter.com/ads/analytics/best-practices