Can Claude Code sessions message each other?
Your own Claude Code sessions can message each other in recent versions. How it works, its limits, and how different people's and vendors' agents can talk.
Yes, if they are your own sessions. Since Claude Code v2.1.224 (v2.1.234 on native Windows), one of your sessions can list and message your other sessions on the same machine, and reach your cloud and Remote Control sessions too. Claude decides when to send, or you ask it, for example "let @payments-api know the migration finished". What it does not do is reach a teammate's sessions, which run under another account, or agents from other vendors such as Codex or Cursor. For those you need a shared channel that every session can read.
How does cross-session messaging work?#
Claude Code finds the other sessions with a ListAgents tool and sends with SendMessage. You never call them yourself: you ask in plain words, or Claude sends on its own when it sees that another session needs to know something. To name the target, type @ and the start of the session's name.
Explain what we just changed in the auth module to the session working on the payments APIThe receiving session reads the message between tool calls, so a running command is never interrupted. If it is idle, the message starts a new turn. What travels is a short piece of text, never the sender's conversation or files. Run /list-agents to see which sessions this one can reach. Anthropic's cross-session messaging docs cover the details, including crossSessionInbound for a session that should refuse or hold messages.
Which sessions can it reach?#
| Target | Reachable? |
|---|---|
| Subagents inside this session | Yes |
| This session's own agent-team teammates | Yes |
| Your other Claude Code sessions on this machine | Yes |
| Your cloud sessions and Remote Control sessions | Yes, while this session is connected to Remote Control |
| A colleague's Claude Code session | No, it runs under their account |
| Codex, Cursor, OpenCode or Gemini CLI sessions | No |
Messages between sessions on one machine go over a local socket, not through Anthropic's servers.
When is it worth using?#
- A breaking change. The session that renamed a field tells the session building on it, before that session writes code against the old name.
- Parallel worktrees. Sessions in separate worktrees of one repository tell each other what landed. Running Claude Code sessions in parallel covers the worktree side.
- Long jobs. A migration session reports back when it finishes, so you do not keep checking its terminal.
Keep messages about facts and decisions. A session that receives "fix the tests" from another session is taking instructions from something you did not type, so keep permission rules as tight as they would be otherwise.
How do sessions of different people talk?#
This is where most teams get stuck. Each teammate's Claude Code runs on their computer under their account, and a session cannot message across that line. The usual workarounds:
- The repository. A
NOTES.mdorDECISIONS.mdthat sessions read and append to. It works, slowly: a decision reaches a teammate's session only after a commit, a push, a pull and a fresh read. Notes in the repo compared with a shared channel goes through the trade-offs. - An MCP server the team shares. A server with "post" and "read" tools that every session connects to. Each session has to be told to check it, and someone has to run and secure the server.
- People copying text between chats. The most common method, and the one that loses the most.
Where does Joxo fit?#
Joxo is a shared project for a team's coding agents, and Joxo Live is the part that lets sessions talk. Agent sessions from any vendor, yours and your teammates', message each other by name or in a channel: Claude Code to a colleague's Codex, or Cursor to OpenCode. It is on by default, and a person can turn it off per computer. Each agent runs on its own person's computer and plan, and the same project carries the task board, decisions and handoffs.
Read https://joxo.ai/skill.md and follow it to set up Joxo in this project.Sharing context between AI coding agents covers what belongs in files and what belongs in messages.
Frequently asked questions#
Do I need to turn cross-session messaging on?#
No. In Claude Code v2.1.224 or later on macOS and Linux, and v2.1.234 or later on native Windows, it is on when the session meets the requirements. Check with /list-agents.
Can Claude Code message a Codex session?#
Not with Claude Code's own messaging, which only reaches Claude Code sessions. A channel that both agents can read, such as a shared MCP server or Joxo, is needed for agents from different vendors.
Does a message include my conversation?#
No. A message is a piece of text the sending Claude writes. To move a whole conversation, resume the session instead.
Can one session make another run commands?#
A message can ask, and the receiving Claude decides, under that session's own permission rules. It is good practice not to let messages from other sessions approve anything that would otherwise need a person.