x-cyrus-jmapquery
 

Just noticed a new extension listed in the sieve script require list called x-cyrus-jmapquery. I can't find a rfc or any documentation on what it does.

I just thought I would point this one out and ask if anyone has any idea on it?

I might submit a ticket and simply ask FM. At least this one doesn't trip up Sieve Tester (and neither does fcc anymore).

There are two immediate reactions. The first is that the 'x-' almost certainly indicates it is experimental, and I definitely would not use it for anything important. Secondly, my guess is that this is something similar to the Environment extension, allowing you to find out information about the JMAP server. Probably the supported items you can query are in a constant state of flux at this stage.

Couldn't use it for anything anyhow not knowing how to use it! :D Thanks for the thoughts though.

I was intrigued enough by this to do some digging. The extension turns out to be pretty interesting. A quick look at the code suggests that JMAP exposes all the basic information about a message as a JSON string. The extension x-cyrus-jmapquery provides a way to extract information from that string. If you are at least somewhat able to read C code, you can get a sense of the way the extension works from https://github.com/cyrusimap/cyrus-i.../sieve/sieve.y

Right now, it looks as though the extension just provides a different way of accessing information already available via regular sieve syntax.

I was luckily selected for a beta test of their new filtering system.

Fastmail is looking to overhaul their user defined rules construction to use JMAP queries (with live preview).

I'm not fully liking the change because in the UI they don't make clear distinctions with traditional sieve rules and JMAP rules. In any case it's a welcome addition.

I hope they nail the UI/UX.

Can it screw up the custom sieve rules?

If you want to switch to the new rules system, you must remove your custom sieve, and reimplement it after the switch. There is nothing about x-cyrus-jmapquery itself that breaks existing sieve syntax. In principle, it provides some additional functionality. However, the automatically generated sieve script looks a little different, and your custom sieve may need reworking.

One more time: It will let you switch to the new rules even if you have existing sieve code in the first and last blocks.

Caveat: At least that was the case as of last week. Haven't tried switching back and forth since I am currently working on my sieve code in new rules mode and I don't want to have to preserve it across switching back and forth.