Inter-session pmail - send and receive messages between Claude Code sessions running in different project directories. Uses global SQLite database at ~/.claude/pmail.db. Triggers on: mail, pmail, send message, check mail, inbox, inter-session, message another session, pigeon.
Scanned 9/5/2026
Install to Claude Code
Skills Directorynpx -y skills add 0xDarkMatter/claude-mods --skill pigeon --agent claude-codeInstalls into .claude/skills of the current project.
Are you the author of Pigeon?
Add the live security badge to your README — it updates automatically with every re-scan.
[](https://www.skillsdirectory.com/skills/0xdarkmatter-pigeon)More formats (shields.io, HTML) on the badges page.
---
name: pigeon
description: "Inter-session pmail - send and receive messages between Claude Code sessions running in different project directories. Uses global SQLite database at ~/.claude/pmail.db. Triggers on: mail, pmail, send message, check mail, inbox, inter-session, message another session, pigeon."
license: MIT
allowed-tools: "Read Bash Grep"
metadata:
author: claude-mods
related-skills: sqlite-ops
---
# Pigeon
Inter-session messaging for Claude Code. Send and receive pmail between sessions running in different projects.
## Quick Reference
All commands go through `MAIL`, a shorthand for `bash "$HOME/.claude/pigeon/mail-db.sh"`.
Set this at the top of execution:
```bash
MAIL="$HOME/.claude/pigeon/mail-db.sh"
```
Then use it for all commands below.
## Command Router
Parse the user's input after `pigeon` (or `/pigeon`) and run the matching command:
| User says | Run |
|-----------|-----|
| `pigeon read` | `bash "$MAIL" read` |
| `pigeon read 42` | `bash "$MAIL" read 42` |
| `pigeon send <project> "<subject>" "<body>"` | `bash "$MAIL" send "<project>" "<subject>" "<body>"` |
| `pigeon send --urgent <project> "<subject>" "<body>"` | `bash "$MAIL" send --urgent "<project>" "<subject>" "<body>"` |
| `pigeon send --attach <path> <project> "<subject>" "<body>"` | `bash "$MAIL" send --attach "<path>" "<project>" "<subject>" "<body>"` |
| `pigeon reply <id> "<body>"` | `bash "$MAIL" reply <id> "<body>"` |
| `pigeon reply --attach <path> <id> "<body>"` | `bash "$MAIL" reply --attach "<path>" <id> "<body>"` |
| `pigeon broadcast "<subject>" "<body>"` | `bash "$MAIL" broadcast "<subject>" "<body>"` |
| `pigeon search <keyword>` | `bash "$MAIL" search "<keyword>"` |
| `pigeon status` | `bash "$MAIL" status` |
| `pigeon unread` | `bash "$MAIL" unread` |
| `pigeon list` | `bash "$MAIL" list` |
| `pigeon list 50` | `bash "$MAIL" list 50` |
| `pigeon projects` | `bash "$MAIL" projects` |
| `pigeon clear` | `bash "$MAIL" clear` |
| `pigeon clear 7` | `bash "$MAIL" clear 7` |
| `pigeon alias <old> <new>` | `bash "$MAIL" alias "<old>" "<new>"` |
| `pigeon purge` | `bash "$MAIL" purge` |
| `pigeon purge --all` | `bash "$MAIL" purge --all` |
| `pigeon id` | `bash "$MAIL" id` |
| `pigeon migrate` | `bash "$MAIL" migrate` |
| `pigeon init` | `bash "$MAIL" init` |
When the user just says "check mail", "read mail", "inbox", "any mail?", or "any pmail?" - run `bash "$MAIL" read`.
When the user says "send mail to X", "send pmail to X", or "message X" - parse out the project name, subject, and body, then run `bash "$MAIL" send`.
## Project Identity
Each project gets a stable 6-character hash ID derived from its **git root commit** (the very first commit in the repo). This means:
- IDs survive directory renames, moves, and clones
- Case-insensitive filesystems (macOS) don't cause collisions
- Every clone of the same repo shares the same identity
For non-git directories, falls back to a hash of the canonical path (`pwd -P`).
Use `pigeon id` to see your project's name and hash:
```
claude-mods 7663d6
```
When sending messages, you can address projects by **name**, **hash**, or **path** - they all resolve to the same hash ID.
### Identicons
Each project hash renders as a unique pixel-art identicon (11x11 symmetric grid using Unicode half-block characters). Run `identicon.sh` to see yours, or view all projects with `pigeon projects`.
## Passive Notification (Hook)
A global PreToolUse hook checks for pmail on every tool call (no cooldown). Silent when inbox is empty.
```
=== PMAIL: 3 unread message(s) ===
From: some-api | Auth endpoints ready
From: frontend | Need updated types
... and 1 more
Use pigeon read to read messages.
```
## Attachments
Send file references with `--attach <path>` (repeatable). Paths are resolved to absolute and stored as references - files are not copied.
```bash
# Send with one attachment
pigeon send --attach src/config.ts my-api "Config update" "Updated the auth config"
# Send with multiple attachments
pigeon send --attach src/schema.sql --attach docs/API.md my-api "Schema + docs" "See attached"
# Reply with attachment
pigeon reply --attach output/report.json 42 "Here's the analysis"
```
Recipients see attachment paths with file sizes and can read them directly with the Read tool. If a file has been moved or deleted since sending, it shows as `(missing)`.
## When to Send
- You've completed work another session depends on
- An API contract or shared interface changed
- A shared branch (main) is broken or fixed
- You need input from a session working on a different project
## Per-Project Disable
```bash
touch .claude/pigeon.disable # Disable hook notifications
rm .claude/pigeon.disable # Re-enable
```
Only the hook is disabled - you can still send messages from the project.
---
## Installation
Pigeon requires two things: **scripts** (the mail engine) and a **hook** (passive notifications). Both install globally - one setup, every project gets pmail.
### Prerequisites
- `sqlite3` - ships with macOS, most Linux distros, and Git Bash on Windows. No install needed.
### Step 1: Copy Scripts
```bash
mkdir -p ~/.claude/pigeon
cp skills/pigeon/scripts/mail-db.sh ~/.claude/pigeon/
cp hooks/check-mail.sh ~/.claude/pigeon/
chmod +x ~/.claude/pigeon/mail-db.sh ~/.claude/pigeon/check-mail.sh
```
This gives you the pmail commands. You can now send and read messages manually:
```bash
bash ~/.claude/pigeon/mail-db.sh init # Create database
bash ~/.claude/pigeon/mail-db.sh status # Check it works
```
### Step 2: Enable the Hook
Add a `hooks` block to `~/.claude/settings.json`. This makes Claude check for pmail automatically on every tool call:
```json
{
"hooks": {
"PreToolUse": [
{
"matcher": "*",
"hooks": [
{
"type": "command",
"command": "bash \"$HOME/.claude/pigeon/check-mail.sh\"",
"timeout": 5
}
]
}
]
}
}
```
**Important:** If you already have a `hooks` section in your settings, merge the PreToolUse entry into the existing array - don't replace the whole block.
Without this step, pigeon still works but you have to check manually (`pigeon read`). With the hook, unread pmail appears automatically.
### What Gets Created
```
~/.claude/
settings.json # Hook config (you edit this)
pmail.db # Message store (auto-created on first use)
pigeon/
mail-db.sh # All pmail commands (send, read, reply, etc.)
check-mail.sh # PreToolUse hook (silent when inbox empty)
```
### Verify
```bash
# Check your project identity
bash ~/.claude/pigeon/mail-db.sh id
# Send yourself a test message (use your project name from above)
bash ~/.claude/pigeon/mail-db.sh send "my-project" "Test" "Hello from pigeon"
# Check it arrived
bash ~/.claude/pigeon/mail-db.sh read
# Clean up
bash ~/.claude/pigeon/mail-db.sh purge --all
```
### Uninstall
```bash
rm -rf ~/.claude/pigeon ~/.claude/pmail.db
# Then remove the hooks.PreToolUse entry from ~/.claude/settings.json
```
## Database
Single SQLite file at `~/.claude/pmail.db`. Auto-created on first `init` or `send`.
```sql
CREATE TABLE messages (
id INTEGER PRIMARY KEY AUTOINCREMENT,
from_project TEXT NOT NULL, -- 6-char hash ID
to_project TEXT NOT NULL, -- 6-char hash ID
subject TEXT DEFAULT '',
body TEXT NOT NULL,
timestamp TEXT DEFAULT (datetime('now')),
read INTEGER DEFAULT 0,
priority TEXT DEFAULT 'normal'
);
CREATE TABLE projects (
hash TEXT PRIMARY KEY, -- 6-char ID (git root commit or path hash)
name TEXT NOT NULL, -- Display name (basename of project dir)
path TEXT NOT NULL, -- Canonical path
registered TEXT DEFAULT (datetime('now'))
);
```
## Troubleshooting
| Issue | Fix |
|-------|-----|
| `sqlite3: not found` | Ships with macOS, Linux, and Git Bash on Windows. Run `sqlite3 --version` to check. |
| Hook not firing | Ensure `hooks` block is in `~/.claude/settings.json` (Step 2 above) |
| Hook fires but no notification | Working as intended - hook is silent when inbox is empty |
| Messages not arriving | Target must be a known name, hash, or path. Use `pigeon projects` to see registered projects |
| Upgraded from basename IDs | Run `pigeon migrate` to convert old messages to hash-based IDs |
| Changed display name | Use `pigeon alias old-name new-name` to update the project's display name |
| Want to disable for one project | `touch .claude/pigeon.disable` in that project's root |
| Check your project ID | Run `pigeon id` to see name and 6-char hash |
Is this your skill, or is something wrong with this listing? Request removal or report an issue. Author removals are honored within 72 hours.
No comments yet. Be the first to comment!
