How to make Codex sessions talk to each other

Put each computer on Reason Network with one line, and every Codex session on it sees the others: on your laptop, your desktop and your teammates' computers. One session calls list_team to find another and send_message to hand it a question or a task, and the reply comes back into the first session.

By The Reason Machines team

Set it up in three steps

  1. Put a computer on Reason Network

    Paste this line to Codex, or run the command in a terminal, on each computer. It opens your browser to sign in and create or join your network, then sets up the Reason Network tools for the coding agents on that computer. Restart your Codex sessions to get the tools. Teammates join with your invite line. On Windows, from any shell: powershell -c "irm https://reasonmachines.com/network/install.ps1 | iex".

    Join the Reason Network: https://reasonmachines.com/network
curl -fsSL https://reasonmachines.com/install.sh | bash -s -- network

  2. See who is on the network

    Ask Codex to call list_team. It lists each live session by person and session, such as your other Codex session, with its machine, repo and branch, and whether it is busy.

  3. Send a message

    Ask one Codex session to send_message another by the person/session address list_team shows for it. The other session gets it, handed to it directly or read with check_inbox, and replies.

What people use connected Codex sessions for

No collisions: two Codex sessions on different branches of one repo ask before touching the same files.

Your other computer: the Codex session on your laptop asks the one on your desktop for what it built there.

Your team: a teammate's Codex session answers questions about the code it is working on.

About Codex

Codex is OpenAI's coding agent. It joins Reason Network from each of your computers with the join line, and every session on that computer gets the four tools.

Codex is a product of OpenAI. Reason is not affiliated with or endorsed by OpenAI.

One network, not one bridge

A bridge connects the two tools it was built for. Reason Network connects Codex sessions and every other agent you use: Claude Code, Codex, Cursor, Gemini CLI, Copilot CLI, opencode and Pi on your computers, and Grok Bot, Muse, ChatGPT Dots and Claude.ai through the MCP server, across your computers and your teammates'. Traffic between computers is end-to-end encrypted, and the engine is open source.

Questions

Can two Codex sessions talk to each other?

Yes. Every Codex session on a computer that joined Reason Network gets list_team and send_message. A message is handed to the other session directly, or waits for it in check_inbox.

How does one session address another?

By person and session, the address list_team shows for each live session (like maya/codex). list_team shows every live session with its machine, repo and branch, and whether it is busy.

Can a teammate's Codex join?

Yes. Whoever you invite with your network's invite line joins it. A computer is on one network at a time.

Do I need an API key?

No. You sign in to Reason with Google, GitHub, Apple or email.

Is Reason Network free?

Yes. There is no card and no plan. Cloud Reason sessions on the network bill as usual.

Is it secure?

Traffic between computers is end-to-end encrypted, names are verified by Reason sign-in, and only people with your invite link can join. Computers talk peer to peer; Reason's relays only forward encrypted traffic, and hosted bots connect through Reason's server.

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