{"slug":"pigeon","title":"pigeon","summary":"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.","platform":"Claude","tags":[],"authorName":"LLM Mart","authorSlug":"llm-mart","score":0,"source":"github","price":null,"verified":false,"createdAt":"2026-09-30T19:36:50.534928Z","repo":{"url":"https://github.com/0xDarkMatter/claude-mods","stars":43,"forks":7,"license":"MIT","updatedAt":"2026-09-30T15:18:48Z"},"bodyHtml":"
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name: pigeon\ndescription: \"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.\"\nlicense: MIT\nallowed-tools: \"Read Bash Grep\"\nmetadata:\nauthor: claude-mods\nrelated-skills: sqlite-ops

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Pigeon

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Inter-session messaging for Claude Code. Send and receive pmail between sessions running in different projects.

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Quick Reference

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All commands go through MAIL, a shorthand for bash \"$HOME/.claude/pigeon/mail-db.sh\".

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Set this at the top of execution:

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MAIL=\"$HOME/.claude/pigeon/mail-db.sh\"\n
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Then use it for all commands below.

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Command Router

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Parse the user's input after pigeon (or /pigeon) and run the matching command:

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User saysRun
pigeon readbash \"$MAIL\" read
pigeon read 42bash \"$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 \"$MAIL\" search \"<keyword>\"
pigeon statusbash \"$MAIL\" status
pigeon unreadbash \"$MAIL\" unread
pigeon listbash \"$MAIL\" list
pigeon list 50bash \"$MAIL\" list 50
pigeon projectsbash \"$MAIL\" projects
pigeon clearbash \"$MAIL\" clear
pigeon clear 7bash \"$MAIL\" clear 7
pigeon alias <old> <new>bash \"$MAIL\" alias \"<old>\" \"<new>\"
pigeon purgebash \"$MAIL\" purge
pigeon purge --allbash \"$MAIL\" purge --all
pigeon idbash \"$MAIL\" id
pigeon migratebash \"$MAIL\" migrate
pigeon initbash \"$MAIL\" init
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When the user just says \"check mail\", \"read mail\", \"inbox\", \"any mail?\", or \"any pmail?\" - run bash \"$MAIL\" read.

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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.

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Project Identity

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Each project gets a stable 6-character hash ID derived from its git root commit (the very first commit in the repo). This means:

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For non-git directories, falls back to a hash of the canonical path (pwd -P).

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Use pigeon id to see your project's name and hash:

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claude-mods 7663d6\n
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When sending messages, you can address projects by name, hash, or path - they all resolve to the same hash ID.

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Identicons

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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.

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Passive Notification (Hook)

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A global PreToolUse hook checks for pmail on every tool call (no cooldown). Silent when inbox is empty. When mail is waiting it prints one JSON envelope, and Claude Code passes its additionalContext to the model:

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{\"hookSpecificOutput\":{\"hookEventName\":\"PreToolUse\",\"additionalContext\":\"=== INCOMING PMAIL (1 message(s)) ===\\n...\"}}\n
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What the model reads:

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=== INCOMING PMAIL (1 message(s)) ===\n\n--- #42 from some-api (a1b2c3) @ 2026-09-30 10:12:04 ---\nSubject: Auth endpoints ready\nLogin and refresh are live on staging.\n\n=== ACTION REQUIRED: Inform the user about these messages and ask if they want to reply. ===\n=== Then run: pigeon read (to mark as read) ===\n=== To reply: pigeon reply <id> \"message\" ===\n
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The JSON form is required. For PreToolUse, plain stdout goes to Claude Code's debug log and never reaches the model. Claude Code caps additionalContext at 10,000 chars, so the hook truncates message bodies at about 9,000 and points at pigeon read. The header and footer are always kept. Delivery does not mark mail read. The signal file is cleared, so each new send triggers one notice.

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Attachments

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Send file references with --attach <path> (repeatable). Paths are resolved to absolute and stored as references - files are not copied.

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# Send with one attachment\npigeon send --attach src/config.ts my-api \"Config update\" \"Updated the auth config\"\n\n# Send with multiple attachments\npigeon send --attach src/schema.sql --attach docs/API.md my-api \"Schema + docs\" \"See attached\"\n\n# Reply with attachment\npigeon reply --attach output/report.json 42 \"Here's the analysis\"\n
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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).

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When to Send

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Per-Project Disable

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touch .claude/pigeon.disable    # Disable hook notifications\nrm .claude/pigeon.disable       # Re-enable\n
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Only the hook is disabled - you can still send messages from the project.

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Installation

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Pigeon requires two things: scripts (the mail engine) and a hook (passive notifications). Both install globally - one setup, every project gets pmail.

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Prerequisites

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Step 1: Copy Scripts

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mkdir -p ~/.claude/pigeon\ncp skills/pigeon/scripts/mail-db.sh ~/.claude/pigeon/\ncp hooks/check-mail.sh ~/.claude/pigeon/\nchmod +x ~/.claude/pigeon/mail-db.sh ~/.claude/pigeon/check-mail.sh\n
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This gives you the pmail commands. You can now send and read messages manually:

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bash ~/.claude/pigeon/mail-db.sh init      # Create database\nbash ~/.claude/pigeon/mail-db.sh status    # Check it works\n
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Step 2: Enable the Hook

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Add a hooks block to ~/.claude/settings.json. This makes Claude check for pmail automatically on every tool call:

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{\n  \"hooks\": {\n    \"PreToolUse\": [\n      {\n        \"matcher\": \"*\",\n        \"hooks\": [\n          {\n            \"type\": \"command\",\n            \"command\": \"bash \\\"$HOME/.claude/pigeon/check-mail.sh\\\"\",\n            \"timeout\": 5\n          }\n        ]\n      }\n    ]\n  }\n}\n
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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.

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Without this step, pigeon still works but you have to check manually (pigeon read). With the hook, unread pmail appears automatically.

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What Gets Created

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~/.claude/\n  settings.json            # Hook config (you edit this)\n  pmail.db                 # Message store (auto-created on first use)\n  pigeon/\n    mail-db.sh             # All pmail commands (send, read, reply, etc.)\n    check-mail.sh          # PreToolUse hook (silent when inbox empty)\n
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Verify

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# Check your project identity\nbash ~/.claude/pigeon/mail-db.sh id\n\n# Send yourself a test message (use your project name from above)\nbash ~/.claude/pigeon/mail-db.sh send \"my-project\" \"Test\" \"Hello from pigeon\"\n\n# Check it arrived\nbash ~/.claude/pigeon/mail-db.sh read\n\n# Clean up\nbash ~/.claude/pigeon/mail-db.sh purge --all\n
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Uninstall

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rm -rf ~/.claude/pigeon ~/.claude/pmail.db\n# Then remove the hooks.PreToolUse entry from ~/.claude/settings.json\n
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Database

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Single SQLite file at ~/.claude/pmail.db. Auto-created on first init or send.

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CREATE TABLE messages (\n    id INTEGER PRIMARY KEY AUTOINCREMENT,\n    from_project TEXT NOT NULL,   -- 6-char hash ID\n    to_project TEXT NOT NULL,     -- 6-char hash ID\n    subject TEXT DEFAULT '',\n    body TEXT NOT NULL,\n    timestamp TEXT DEFAULT (datetime('now')),\n    read INTEGER DEFAULT 0,\n    priority TEXT DEFAULT 'normal'\n);\n\nCREATE TABLE projects (\n    hash TEXT PRIMARY KEY,        -- 6-char ID (git root commit or path hash)\n    name TEXT NOT NULL,           -- Display name (basename of project dir)\n    path TEXT NOT NULL,           -- Canonical path\n    registered TEXT DEFAULT (datetime('now'))\n);\n
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Troubleshooting

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IssueFix
sqlite3: not foundShips with macOS, Linux, and Git Bash on Windows. Run sqlite3 --version to check.
Hook not firingEnsure hooks block is in ~/.claude/settings.json (Step 2 above)
Hook fires but no notificationWorking as intended - hook is silent when inbox is empty
Mail is unread but Claude never mentions itThe hook must print JSON additionalContext, because plain PreToolUse stdout only reaches the debug log. Reinstall check-mail.sh from this repo and check jq --version
Messages not arrivingTarget must be a known name, hash, or path. Use pigeon projects to see registered projects
Upgraded from basename IDsRun pigeon migrate to convert old messages to hash-based IDs
Changed display nameUse pigeon alias old-name new-name to update the project's display name
Want to disable for one projecttouch .claude/pigeon.disable in that project's root
Check your project IDRun pigeon id to see name and 6-char hash
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