National Grid (in UK) have released an API which spits out current and 2 day forecast for grid carbon intensity. See:
It uses Elexon data for current figure so should be broadly consistent with other tools such as GridCarbon, Earth Notes, and OEMs own tool (the carbon intensity factors used and inclusion of interconnectors varies a bit between each one).
They also have some interesting integrations/apps on their github:
Yes, I saw this It’s really great to have an official APi with predictions 
I’ve shown it to @TrystanLea, hopefully we can get it integrated with some smart grid work. A starting point would be to get the data from the APi into Emoncms for easy access and graphing.
@beaylott, do you know what the boundaries are for the various CI levels?
So V Low is 0 to what level?