Only state I keep is filesystem and last message (but even that is persisted in the filesystem). Each agent gets its own btrfs volume, when it’s done the “next” agent get the previous agent work mounted in its own filesystem ( and told about it ). Agent is also able to “promote” files if it wants and they are mounted in a more prominent place.

I don’t know yet if it’s a good solution. But only thinking in terms of files / filesystem sure make things easier.

Also makes branching “easier”: no handling of merging or conflicts, the receiving agent just gets N file systems and decides how to handle things.