JMAP: The Specs
The specifications for the core JMAP protocol and access to mail stores using JMAP have been finalised and published. The JMAP working group is currently working on the calendars and sharing specs, with tasks and contacts expected to follow.
These specs are not yet final and will change before publication. There are undoubtably edge cases that are not yet covered. If you find one, please email firstname.lastname@example.org or make a pull request on GitHub if you have a proposed fix.