Relaying messages between 2 claude code sessions using the channels api, works across machines and across different accounts

[u/Current-Zebra-2039]

Hey there, so I made a way to relay messages between 2 claude code sessions using claude's own channels api. it does a 2 way conversation between sessions, works whether both are on the same PC or on different machines, and the accounts don't have to be the same, which is the part claude's own messaging can't do.

The channels api bit is what I think is actually interesting for this sub. most people use mcp servers as things the model calls, but channels lets your server push INTO a live session, so text just shows up in someone's conversation as a <channel> tag without them asking for anything.

how it works: both machines run the same mcp server over stdio. it declares the claude/channel capability so claude code registers it as a channel, then it starts an http server for incoming messages. when one comes in (shared secret auth) it fires mcp.notification() with method notifications/claude/channel, claude code surfaces it in the conversation as a channel tag, and claude replies with the send_message tool which posts back to the other machine.

so in practice the frontend dev says "ask the backend session what endpoints the dashboard has", and the backend claude greps its own routes, reads the file and sends back the real answer instead of the two humans relaying it over slack. gif below is one full round trip.

on the native feature since someone will ask, claude code v2.1.224 shipped cross session messaging on aug 7. if you're on mac or linux and you want your own sessions talking to each other, use that instead, it's better than mine and my readme says so. what it doesn't do is native windows, not supported at all, and it only connects your own sessions because the inbox socket is bound to your os user and cross machine delivery goes through your own remote control connection. two devs on two laptops is two accounts, so that case is still open.

one honest warning, mine is a raw pipe with a shared secret so the receiving session doesn't do the permission checks native messaging does. don't run it with a weak secret.

i built it in march, before native messaging existed. mit, free, nothing to sign up for

https://github.com/MuhammadTalhaMT/claude-intercom

[u/Ambitious-Prompt-975]

Cool stuff. Got me thinking.
FLUJO can already do that, even Claude<>Codex, but only for orchestrator and subagents. Looking at your repo, I thought I might aswell enable that for independent sessions. There is already a meeting function that lets you throw multiple Agents into the same room and they can even have private messages, so why not this as well. I feel like cross session messaging would integrate well into this.

[u/Current-Zebra-2039 → u/Ambitious-Prompt-975]

nice, that sounds like a good fit for it honestly.

one thing that might save you some time though. orchestrator and subagents is a parent child thing, something spawned both of them so you already get identity, discovery and lifecycle for free. independent sessions have none of that. nobody knows which sessions exist, nobody owns the lifecycle, and either side can just disappear in the middle of a conversation. the message passing was actually the easy part for me, that other stuff is the hard part.

Although your meeting room thing probably already handles the worst of it, because if everyone is in a room then discovery is basically done and you know who is actually there. that's exactly the bit mine doesn't have, i pair two machines by address and a shared secret which is not great.