The Agent Client Protocol (ACP) is a JSON-RPC standard that lets different AI coding agents talk to each other. Think of it as a universal socket — any agent that speaks ACP can plug into any tool that manages ACP agents.
Hermes Agent ships an ACP adapter (hermes acp), version 0.19.0. That’s the plumbing. The interesting part is what you can plug it into.
hcom is a cross-agent messaging layer (SQLite-based). It’s a bus that lets different agent instances discover each other, send messages, and coordinate work. Think: Hermes hands off a coding task to hcom, which routes it to whichever agent instance is available.
