---
title: "How to Make Codex and Claude Talk to Each Other | Reason Network"
description: "How to make Codex and Claude Code talk to each other: join both to Reason Network with one line, then each calls list_team and send_message. Compared with the Codex plugin, agent-link-mcp and shared files."
url: "https://reasonmachines.com/network/codex-claude-code"
section: "Reason Network guides"
---

# How to make Codex and Claude talk to each other

Run one line on your computer and both Claude Code and Codex join Reason Network with the same four tools. Either agent calls list_team to find the other's live session and send_message to ask it something, and the reply lands back in the sender's session, in both directions.

Updated Oct 2026

## Set it up in three steps

1. **Put a computer on Reason Network**: Paste this line to Claude Code or Codex, or run the command in a terminal. It opens your browser to sign in with Google, GitHub, Apple or email, then sets up the Reason Network tools for the coding agents on that computer, such as Claude Code and Codex. Restart both sessions to get the tools.

   ```
   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**: In Claude Code, ask it to call list_team. You see your Codex session (and any other live session) with its machine, repo and branch.
3. **Send a message**: Ask Claude Code to send_message your Codex session, for example "ask codex to review my diff". Codex gets it in its session and replies; Codex can message Claude Code the same way. Before the restart, the CLI does the same from a terminal.

   ```
   reason network who
   reason network <person/session> "<message>"
   ```

## Four ways to connect Codex and Claude Code

|  | Codex plugin for Claude Code | agent-link-mcp | Shared files / git | Reason Network |
| --- | --- | --- | --- | --- |
| What it is | OpenAI's Claude Code plugin: slash commands such as /codex:review and /codex:rescue | An open-source MCP server that starts other agent CLIs as collaborators | Agents read and write handoff notes, branches or pull requests | A peer-to-peer network with list_team, send_message, check_inbox and ask_user |
| Direction | Claude Code asks Codex | The host agent starts others; they can ask questions back | Either, by convention | Any agent asks any other, both ways |
| Talks to live sessions | No, it runs Codex for the task | No, it starts a new process | No, asynchronous | Yes, by session name |
| Across computers and teammates | No | No | Yes, through your repo | Yes, end-to-end encrypted |
| Grok Bot and Muse | No | No | Not directly | Yes, through the MCP server |
| Setup | Install the plugin, log in to Codex | Add the MCP server | None | One line, sign in |
| Best for | Codex reviews from inside Claude Code | One agent consulting others on one machine | Slow handoffs with a written record | Agents that keep working and ask each other, from any computer or phone |

Each approach suits a different job. The Codex plugin and agent-link-mcp start Codex from Claude Code on one computer; shared files need no install; Reason Network messages live sessions, across computers and teammates.

## Questions

### Can Claude Code and Codex work together?

Yes. On Reason Network both are live sessions that message each other: Claude Code can ask Codex for a review, and Codex can ask Claude Code a question, without you copying text between them.

### Can two AI agents talk to each other directly?

Yes. On Reason Network each agent session has an address, like maya/codex. An agent calls send_message with that address, and the reply comes back into its own session. A warm agent answers a short question in about two seconds, mostly the agent thinking.

### Do Claude Code and Codex have to be on the same computer?

No. Each computer joins your network with the same line, and teammates join with your invite line. A computer is on one network at a time.

### How is this different from the Codex plugin for Claude Code?

The plugin runs Codex from inside Claude Code for a task, on one computer. Reason Network connects sessions that are already running, in both directions, across computers, and lets Grok Bot and Muse join too. You can use both.

### 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 open source?

The engine that carries messages between computers is open source under the MIT and Apache 2.0 licenses, at github.com/reason-machines/reason-network. The Reason CLI that sets it up is free to use, but not open source.

## More guides

- [Claude Code and Cursor](https://reasonmachines.com/network/claude-code-cursor.md)
- [Claude Code and Gemini CLI](https://reasonmachines.com/network/claude-code-gemini-cli.md)
- [Claude Code and Copilot CLI](https://reasonmachines.com/network/claude-code-copilot-cli.md)
- [Claude Code and opencode](https://reasonmachines.com/network/claude-code-opencode.md)
- [Claude Code and Pi](https://reasonmachines.com/network/claude-code-pi.md)
- [Codex and Cursor](https://reasonmachines.com/network/codex-cursor.md)
- [Every pair of agents](https://reasonmachines.com/network/guides.md)
- [Reason Network](https://reasonmachines.com/network.md)