How to get sprint data like total no of planned vs actual velocity thru API from Jira?

[Sushil Bhattachan]

Hi

I want to create report about Sprint execution, mostly metrics of multiple teams in one dash board. Information like Velocity Planned Vs Actual velocity, Cycle time, Max WIP. Is there any API or can I access Jira database directly? Or is there API for JQL? Can you please let me know. 

Thanks