Claude-skill-registry agentmail

Inter-agent communication for tmux sessions. Send and receive messages between AI agents.

install

source · Clone the upstream repo

git clone https://github.com/majiayu000/claude-skill-registry

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/majiayu000/claude-skill-registry "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/data/agentmail" ~/.claude/skills/majiayu000-claude-skill-registry-agentmail && rm -rf "$T"

manifest: skills/data/agentmail/SKILL.md

AgentMail Skill

AgentMail enables communication between AI agents running in different tmux windows through a simple file-based mail system.

Overview

AgentMail is a CLI tool for inter-agent communication within tmux sessions. Messages are stored in

.agentmail/mailboxes/

as JSONL files, providing persistent, file-locked message queues for each agent.

Prerequisites

Must be running inside a tmux session
AgentMail CLI must be installed and available in PATH
Messages stored in
```
.agentmail/
```
directory

Core Commands

Send a Message

agentmail send <recipient> "<message>"

Send a message to another agent. The recipient must be a valid tmux window name.

Examples:

agentmail send agent2 "Can you review the changes in src/api?"
agentmail send -r worker -m "Task completed"
echo "Build succeeded" | agentmail send agent2

Receive Messages

agentmail receive

Read the oldest unread message from your mailbox. Messages are delivered in FIFO order and marked as read after display.

List Recipients

agentmail recipients

List all tmux windows that can receive messages. Your current window is marked with

[you]

Set Status

agentmail status <ready|work|offline>

Set your availability status:

```
ready
```
- Available to receive messages and notifications
```
work
```
- Busy working (suppresses notifications)
```
offline
```
- Not available (suppresses notifications)

Workflow

Checking for Messages

Run
```
agentmail receive
```
to check for new messages
If a message is available, read and process it
Optionally reply using
```
agentmail send
```

Sending Messages

Run
```
agentmail recipients
```
to see available agents
Send your message:
```
agentmail send <recipient> "<message>"
```
Confirm delivery via the returned message ID

Status Management

The plugin automatically manages your status:

Session start: Status set to
```
ready
```
Session end: Status set to
```
offline
```
End of turn (Stop): Status set to
```
ready
```
, checks for new messages

Message Format

Messages include:

ID: Unique 8-character base62 identifier (a-z, A-Z, 0-9)
From: Sender's tmux window name
To: Recipient's tmux window name
Content: Message body

Best Practices

Check messages regularly - Use
```
agentmail receive
```
to stay informed
Keep messages concise - Focus on actionable information
Include context - Reference files, line numbers, or specific details
Respond promptly - Other agents may be waiting for your input
Use status appropriately - Set
```
work
```
when focusing on complex tasks

Integration with Claude Code

This plugin integrates with Claude Code hooks:

SessionStart: Automatically sets status to
```
ready
```
and runs onboarding
SessionEnd: Automatically sets status to
```
offline
```
Stop: Sets status to
```
ready
```
and checks for new messages

The hooks ensure agents are properly registered and can receive notifications from the mailman daemon.

Troubleshooting

"Not in a tmux session"

AgentMail requires tmux. Start a tmux session first.

"Recipient not found"

The recipient window doesn't exist. Check available windows with

agentmail recipients

"No unread messages"

Your mailbox is empty. Other agents haven't sent you messages yet.

Messages not being delivered

Ensure the mailman daemon is running:

agentmail mailman --daemon