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agent-intercom

Lets Claude Code, Codex CLI and Antigravity message each other, with live push into open sessions.

CommunicationJavaScriptv0.2.5

npm CI License: MIT GitHub stars

Node 20+ Zero dependencies MCP Claude Code Codex CLI Antigravity

Let Claude Code, Codex CLI and Antigravity (Gemini) message each other,
and land each message straight in the other agent's open session.

If it saves you time, a ⭐ helps other people find it.

Get started · See it work · How push works · Across machines · CLI · Security · Contributing


Get started

npx agent-intercom install

Using Claude Code only? Install it as a plugin instead:

/plugin install agent-intercom --marketplace iambashar/agent-intercom

On Claude Code older than 2.1.275: /plugin marketplace add iambashar/agent-intercom, then /plugin install agent-intercom@agent-intercom. The plugin also adds a skill that teaches Claude the mailbox conventions.

The npx command registers the MCP server with every CLI it finds. Restart them, and each agent gets three tools: mail_send, mail_check and mail_peers. Then ask in plain words:

You → Claude: Ask codex to review the diff in src/parser.ts and wait for its answer.

Turn on live push so nobody has to poll. Install it globally, because the daemon needs a stable path:

npm i -g agent-intercom
agent-intercom install --push
What install changes, per CLI
CLIRegistrationExtra for push
Claude Codeclaude mcp add, user scopenothing; uses Claude Code's peer socket
Codex CLIa managed block in ~/.codex/config.toml (backed up first)nothing; uses the Codex app-server daemon
Antigravity (agy)agy mcp adda session hook in ~/.gemini/config/hooks.json

Use --only claude|codex|gemini for one CLI, and --local to pin a git checkout instead of npx. agent-intercom uninstall removes all of it, including the push daemon.

[!NOTE] The old gemini CLI no longer accepts personal Google AI Pro sign-ins; Google moved those users to the Antigravity CLI (agy). Its agent is named gemini here by default.

See it work

Neither agent polls. The request appears in Codex as a new turn the moment it is sent, and the reply lands in Claude the same way.

What you get

Live push, no polling: new mail becomes a new turn in the open session Three CLIs, one inbox: Claude Code, Codex CLI and Antigravity share one mailbox
Delivered exactly once: messages are claimed before a push Zero dependencies: plain Node 20+ and a folder of JSON files
Across machines: bridge.sh moves mail over SSH Local and labelled: nothing leaves your machine, pushed text is tagged

Supported agents

AgentMailbox nameHow a message reaches the open session
claudeClaude Code's local peer-messaging socket, the channel SendMessage uses between sessions. Arrives labelled as from another session.
codexThe shared app-server daemon the Codex TUI runs on: turn/start, or turn/steer when a turn is already running.
geminiagy agentapi send-message into the conversation. Each session registers itself once through a hook.
Any other MCP clientanythingNo push. It reads with mail_check, or blocks with mail_check(wait_seconds=300).
ToolWhat it does
mail_send(to, body, reply_to?)Drop a message in another agent's inbox
mail_check(wait_seconds?)Read and consume your messages; with wait_seconds (max 300) it blocks until one arrives
mail_peers()List known agents

How push works

sequenceDiagram
    autonumber
    participant C as Claude Code
    participant M as ~/.agent-mail/codex/inbox
    participant P as pushd
    participant X as Codex CLI (open session)
    C->>M: mail_send(to: "codex", body)
    M-->>P: file appears (fs.watch, no polling)
    P->>M: claim: rename to <id>.json.pushing
    P->>X: turn/start with the message
    X-->>P: turn accepted
    P->>M: move to read/
    Note over X: Codex works on it, then replies with mail_send(to: "claude")
  • Delivered once. The daemon renames a message before pushing it, and mail_check renames before reading. Whoever wins the rename delivers it.

  • Fails safe. A failed push puts the file back in the inbox and retries after 30 s. If no session is open, the message waits for mail_check.

  • Addressing. Pick a session with claude.<session-name>, codex.<thread-id-prefix> or gemini.<conversation-prefix>. Otherwise the most recently active session gets it, or the one named in ~/.agent-mail/routes.json:

    { "claude": "api-server", "codex": "019f018a" }
    

[!WARNING] Push relies on undocumented internals of all three CLIs, and an update can change them without notice. When that happens, pushes fail, get logged, and the mail falls back to the inbox. Protocol details: docs/live-push.md.

Without the push daemon
  • Claude Code: docs/claude-monitor.md. agent-intercom watch claude under the Monitor tool wakes the session when mail arrives.
  • Codex: docs/codex-listen.md. A listener prompt that loops on mail_check(wait_seconds=300).

Across machines

Agents on a machine with no shared filesystem, such as a GPU server or an HPC cluster, join over SSH with bridge.sh. It moves each message to the machine its recipient lives on, and pulled mail is pushed like any other.

BRIDGE_HOST=gpu-box REMOTE_AGENTS="claude-gpu" ./bridge.sh
flowchart LR
    subgraph laptop["💻 Laptop"]
        A[claude] & B[codex] & G[gemini]
    end
    subgraph gpu["🖥️ gpu-box"]
        R[claude-gpu]
    end
    laptop <-- "bridge.sh · rsync over SSH" --> gpu

More: docs/remote-bridge.md.

More than one session per CLI

Names are just AGENT_NAME. Give each session its own, for example claude-api and claude-web:

npx agent-intercom install --only claude --claude-name claude-api

CLI

agent-intercom install [--only claude|codex|gemini] [--claude-name N] [--codex-name N] [--gemini-name N] [--local] [--push]
agent-intercom uninstall        MCP entries, agy hook and push daemon
agent-intercom push install     push daemon as a login service (launchd / systemd --user)
agent-intercom push uninstall
agent-intercom push run         push daemon in the foreground
agent-intercom status           unread/read counts per agent
agent-intercom watch <name>     one line per new message, without consuming it
agent-intercom serve            the MCP server on stdio

Security

This is a local mailbox with no authentication. Any process running as you can write to ~/.agent-mail/*/inbox, and an agent treats a message as input to act on. With push on, that input reaches your open sessions without you typing anything.

  • Treat inbox contents as untrusted text. Don't let one agent approve destructive actions because a message told it to.
  • Pushed messages are labelled [agent-intercom] message <id> from <sender>. Claude Code also marks them as from another session, not from you.
  • Push reads tokens only your user can read (~/.claude/sessions/*.key, the agy session token) and talks only to local sockets. Nothing leaves the machine.

See SECURITY.md to report a problem. Set AGENT_MAIL_DIR to move the mailbox, for example into a project folder.

🤝 Contributing

Contributions are welcome, from a typo fix to support for a new agent.

Good first issues Help wanted Discussions

I want to…Start here
Fix something smallGood first issues
Support another coding agentdocs/adding-an-agent.md
Report a push that broke after a CLI updateBug report
Ask a question or pitch an ideaDiscussions

Read CONTRIBUTING.md before opening a pull request. Everyone here follows the code of conduct.

Develop

git clone https://github.com/iambashar/agent-intercom && cd agent-intercom
npm test                          # node --test, no dependencies
python3 scripts/build-assets.py   # rebuild the README artwork

Zero runtime dependencies; Node 20+. See CONTRIBUTING.md and the changelog.

MIT licensed · made for people who run more than one coding agent

⭐ Star · 🐛 Report a bug · 💡 Discuss

Installation

Source-derived launch command. Check the maintainer’s required arguments and credentials before running:

bash
npx -y agent-intercom

Set up in your AI client

Merge this template into ~/Library/Application Support/Claude/claude_desktop_config.json. Keep existing servers. Add any arguments, credentials, and permissions required by the maintainer; this template has not been install-tested.

json
{
  "mcpServers": {
    "io-github-iambashar-agent-intercom": {
      "command": "npx",
      "args": [
        "-y",
        "agent-intercom"
      ]
    }
  }
}

Restart Claude Desktop completely for changes to take effect. Confirm the server appears connected in the client’s tool list, then try a read-only example from its documentation.

Claude Desktop setup reference

Package

agent-intercomnpm

Compatible MCP Clients

agent-intercom works with any MCP-compatible client. Copy the config snippet from the Configuration section above and add it to the file shown for your client, then restart the application.

  • Claude Desktop~/Library/Application Support/Claude/claude_desktop_config.jsonRestart Claude Desktop completely for changes to take effect.
  • Cursor~/.cursor/mcp.jsonRestart Cursor for changes to take effect.
  • VS Code.vscode/mcp.jsonReload VS Code window for changes to take effect.
  • Windsurf~/.codeium/windsurf/mcp_config.jsonRestart Windsurf for changes to take effect.
  • Claude Code.mcp.jsonSave at the project root, then start Claude Code in that project and review the MCP server approval prompt. Keep real credentials out of shared files.

Learn More