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

# How to make Codex and Claude Code talk to each other

Ask Claude Code or Codex on your computer to join Reason Network, and both get 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 Nov 2026

[Start with Reason](https://reasonmachines.com/) on the web, or [download Reason for macOS](https://reasonmachines.com/download).

## Set it up in three steps

1. **Put your computer on Reason Network**: On your Mac or PC, tell Claude Code or Codex: "Join the Reason Network: https://reasonmachines.com/network". 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.
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, and whether it is busy.
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.

## 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 | Ask your agent to join, 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.

- [OpenAI: Codex plugin for Claude Code](https://github.com/openai/codex-plugin-cc)
- [agent-link-mcp: official README and tool behavior](https://github.com/mikusnuz/agent-link-mcp)
- [Reason Network](https://reasonmachines.com/network.md)
- [Codex vs Claude Code](https://reasonmachines.com/guides/codex-vs-claude-code.md)

## 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 the same way, 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 software that sets it up is free to use, but not open source.

## More guides

- [Codex vs Claude Code](https://reasonmachines.com/guides/codex-vs-claude-code.md)
- [Claude Code usage limit reached: what to do](https://reasonmachines.com/guides/claude-code-usage-limit.md)
- [How the Claude usage limit works](https://reasonmachines.com/guides/claude-usage-limit-explained.md)
- [When the Claude weekly limit resets](https://reasonmachines.com/guides/claude-weekly-limit-reset.md)
- [Codex usage limit: what to do](https://reasonmachines.com/guides/codex-usage-limit.md)
- [Claude Code alternatives, free ones included](https://reasonmachines.com/guides/claude-code-alternatives.md)
- [All coding agent guides](https://reasonmachines.com/guides.md)
- [Download Reason for macOS](https://reasonmachines.com/download)