My agents finally have a shared mailbox. I still have to wake them up myself.

Hi there, I run a handful of AI agents that hand tasks to each other. For a long time the handoff was me, copying messages from one chat into the next. So we built a shared mailbox: basically a git repo with one folder per agent and strict rules for handoffs. It works. Messages arrive, land in the right folder, and you can trace who sent what. Then nothing happens. Writing a file to GitHub doesn't wake up a chat session. Tasks sat in the inbox until I went into the chat and asked whether there was any mail. So I stopped being the clipboard and became the doorbell ringer instead. Small progress, same job. The part I find interesting: delivered, read, started and actually done are four different states, and most setups I've seen track two of them at best. How do you handle the wake-up part? Polling, webhooks, a coordinator agent that nudges the others, or is a human still ringing the bell on your end? I am pretty interessted in your experiences. Common knowledge could help to get some sleep ;-)(couldn't insert an image, so sorry.)