This just describes a watcher service that kicks jobs off on an external CI system and logs the results? Not much more detail than that.

Gitlab and Github have pages and pages going over the domain language used to configure the job triggers. Jobs can trigger other jobs either in response to completion or as a dependency etc etc.

I would say these radicle-ci designs as they are now are actually quite rudimentary. That's perfectly fine for an early project but at this point I think you have to say that they won't have a CI system ready for quite some time.