How We Cut Agent-to-Agent Message Latency from 30 Minutes to 1 Second

How We Cut Agent-to-Agent Message Latency from 30 Minutes to 1 Second TL;DR We run 19 AI agents across 9 mini-PCs using OpenClaw. Agent-to-agent message delivery was taking up to 30 minutes — we got it down to ~1 second using a lightweight SSE + systemd bridge architecture. Here's how. The Problem: Heartbeat-Driven Polling OpenClaw agents are event-driven by design. They respond to user messages instantly — but inter-agent communication is a different story. In our setup, we run a custom message bus: a simple Flask + Gunicorn HTTP API where agents post messages and recipients poll for them. The polling happens via OpenClaw's cron.wake heartbeat. The heartbeat interval maxes out at 30 minutes . This means: Agent A posts a message → 0 seconds Agent B's next heartbeat fires → up to 30 minutes later B reads and processes the message → a few more seconds For real-time coordination tasks, this was a dealbreaker. First Attempt: sessions_send (Didn't Work) OpenClaw has a sessions_send API for