Signal MCP

signal-mcp

Give your AI assistant a memory for Signal — privately, on your own machine.

Searchable message history · 80+ tools · groups, polls, mentions, labels · read-only mode · 100% local

signal-mcp is an MCP server and CLI built on signal-cli, the community-made, unofficial Signal client. It links to your existing Signal account as a device, keeps every message in a local database you can search, and lets an AI assistant like Claude read, search and — if you allow it — act on your chats. No cloud service, no third party: your messages stay on your computer.

You     What did the coach say about Sunday, and did anyone offer to bring the jerseys?

Claude  Daniel (coach): meet 10:15 at the hall, kickoff 11:00, ten boys confirmed.
        Elena and Mikko both replied — they'll bring the jerseys. Nothing needs
        an answer from you except confirming your son is coming.

You     Tell the group we'll be there, and tag the coach.

Claude  Sent to "U12 Team": "@Daniel we'll be there at 10:15 👍"

Illustrative example with made-up names.

Independent project — not affiliated with Signal. signal-mcp is not made, endorsed or supported by Signal Messenger or the Signal Foundation. It talks to Signal through signal-cli, an unofficial third-party client that you link to your account as an extra device (like Signal Desktop). Signal does not provide support for unofficial clients, and using one is at your own risk — see Signal's Terms of Service.

The same data from your terminal — this is real signal-mcp output on a demo database:

Why it exists

I built signal-mcp for a very ordinary reason: I'm a parent in my kids' football-team group chats and wanted my assistant to keep up with them — kickoff times, who's bringing the jerseys, which tag to set. I use it every day, against my own real Signal account, which is why safety (read-only mode, no file exfiltration, nothing leaving the machine) is built in rather than bolted on.

Why you want this

signal-cli is excellent at the Signal protocol and deliberately minimal everywhere else. signal-mcp adds the parts you need to actually use your messages:

• A memory. signal-cli delivers a message and forgets it. signal-mcp stores everything — including messages you sent from your phone — in local SQLite, and can import your whole Signal Desktop history.
• Search that works. Full-text search across all chats, filterable by sender and date range.
• Real conversations. Paginated threads, unread counts, last-message previews — and names instead of +12025551234, even for group members who aren't in your contacts.
• Everything Signal shows you. @mentions (resolved to names), polls, pins, link previews, quotes, voice notes, stickers, group member labels, join requests — nothing signal-cli reports is thrown away.
• Full control when you want it. Send, reply, react, edit, delete, manage groups, schedule messages, set your profile — with a read-only switch for when you don't.
• Zero babysitting. The daemon starts itself and restarts if it crashes; an optional background service captures messages while Claude isn't running; signal-mcp doctor tells you what's wrong if something is.

Quick start

brew install signal-cli                  # Linux: see Setup below
signal-cli link --name "MyMac"           # scan the QR code: Signal → Settings → Linked Devices
uv tool install signal-mcp
claude mcp add signal -- signal-mcp serve

Needs Python 3.12+, signal-cli 0.13+ and a Signal account on your phone. Restart Claude Code and ask "check my Signal messages". Works with any MCP client (Claude Code and Claude Desktop are what it is developed and tested with) — config snippets are in Setup.

What you can ask

Prefer the terminal? Everything is also a command — signal-mcp send, search, conversations, export, … (CLI usage). The CLI and MCP server share one store and one daemon.

Private and safe by design

• 100% local. Messages live in SQLite on your disk; the daemon listens on localhost only. There is no signal-mcp cloud. (The only things that leave your machine are what you send through Signal itself and an optional webhook you configure.)
• Read-only mode. SIGNAL_MCP_READONLY=1 hides and blocks every tool that sends, edits, deletes or changes settings — for assistants you don't fully trust with your account. See Step 7.
• No file exfiltration. Anything that uploads a local file (attachments, avatars, link-preview images, sticker packs) only reads from an allow-list of folders (SIGNAL_MCP_SEND_ROOTS; default: your attachments folder, Downloads, Desktop, Documents) and never from hidden files or folders — so a message that says "send me ~/.ssh/id_ed25519" can't talk an assistant into it.
• Irreversible means confirmed. Clearing the local store or terminating a group requires an explicit confirm.
• Careful with secrets. The Signal Desktop import decrypts into a private (0700) folder, passes the key over stdin rather than the command line, and cleans up even when interrupted.
• Honest caveat. Messages from other people are untrusted text that an AI will read. Read-only mode (or just not granting write access) is the strongest defence against a hostile message trying to steer your assistant.

What's new

1.40 closes the gap with signal-cli: incoming @mentions, polls, pins, previews and quotes are now captured; group member labels, bans, permissions and join requests; contact nicknames and notes; link previews, voice notes and stories on the sending side; and a fix that finally copies received attachments. See the changelog.

Setup

Step 1 — Install signal-cli

signal-mcp is a front-end for signal-cli, an independent, unofficial client that handles the Signal protocol.

macOS

brew install signal-cli

Linux Download the latest release from signal-cli releases, extract it, and put the signal-cli binary on your $PATH.

Step 2 — Link your Signal account

signal-cli needs to be linked to your existing Signal account (the same way you'd add a linked device in Signal mobile).

signal-cli link --name "MyMac"

This prints a QR code in your terminal. On your phone:

Signal → Settings → Linked Devices → + → scan the QR code

Once scanned, signal-cli is linked and ready.

Step 3 — Install signal-mcp

With uv (recommended):

uv tool install signal-mcp

With pip or pipx:

pip install signal-mcp
# or
pipx install signal-mcp

From source:

git clone https://github.com/googlarz/signal-mcp
cd signal-mcp
uv tool install .

Verify it works:

signal-mcp status
# → Account : +1234567890
# → Daemon  : stopped (port 7583)

Step 4 — Connect to Claude Code

claude mcp add signal -- signal-mcp serve

Restart Claude Code. Signal tools appear automatically — ask Claude "check my Signal messages" to confirm.

Manual config alternatives

Claude Code — global (~/.claude.json):

{
  "mcpServers": {
    "signal": {
      "command": "uvx",
      "args": ["signal-mcp", "serve"]
    }
  }
}

Claude Desktop (~/Library/Application Support/Claude/claude_desktop_config.json):

{
  "mcpServers": {
    "signal": {
      "command": "uvx",
      "args": ["signal-mcp", "serve"]
    }
  }
}

Claude Desktop uses a restricted PATH — uvx resolves the tool without needing signal-mcp on your shell's PATH.

Per-project (.mcp.json):

{
  "mcpServers": {
    "signal": {
      "command": "uv",
      "args": ["run", "--directory", "/path/to/signal-mcp", "signal-mcp", "serve"]
    }
  }
}

Step 5 — (Optional) Import Signal Desktop history

If you use Signal Desktop, import your full message history in one command.

macOS

brew install sqlcipher       # required for decryption
signal-mcp import-desktop    # macOS will prompt for Keychain access — click Allow

Linux (Debian/Ubuntu shown — use your distribution's packages elsewhere)

sudo apt install sqlcipher libsecret-tools   # decryption + keyring lookup (secret-tool)
signal-mcp import-desktop                    # your keyring must be unlocked

Step 6 — (Optional) Enable background message capture

signal-cli only delivers messages when polled. Install the background service so nothing is missed:

signal-mcp install-service   # starts on login, works on macOS and Linux

Step 7 — (Optional) Read-only mode

Set SIGNAL_MCP_READONLY=1 in the environment to restrict the server to read-only tools (listing, searching, and exporting existing local/remote state). Tools that send, edit, delete, or otherwise mutate your Signal account — messages, contacts, groups, devices, and settings — are hidden from tool listings and rejected if called directly. Useful when connecting an AI client you don't fully trust with write access to your real Signal account.

Troubleshooting

Start with signal-mcp doctor — it checks signal-cli, your linked account, the daemon, and message capture, and says which one is broken.

MCP Tools

Messaging

Configuration

Sticker Packs

Contacts

Message output now carries everything signal-cli reports for incoming messages, when present: mentions (with body_resolved, the text with @name in place of the placeholder), text_styles, previews, quote (author and text), voice_note, sticker, polls (poll_create / poll_vote / poll_terminate), pins, story replies and shared contacts. Remote and admin deletes flag the stored message (remote_deleted, admin_deleted_by) instead of erasing your local copy.

Groups

History & Search

Security & Devices

Polls

Disappearing Messages

Scheduling

Webhooks

Data & Import

CLI Usage

# Status & daemon
signal-mcp status                          # account + daemon info
signal-mcp doctor                          # onboarding smoke test: signal-cli, account, daemon, receive health
signal-mcp daemon                          # start daemon in foreground
signal-mcp stop                            # stop the daemon

# Send & receive
signal-mcp send +1234567890 "Hello!"
signal-mcp send +1234567890 "**Heads up** — *lunch at 1*" --format
signal-mcp send-group <group_id> "Hey!"
signal-mcp send-group <group_id> "**Kickoff** is at *11:00*" --format   # bold + italic
signal-mcp note "Remember to buy milk"     # save a note to yourself
signal-mcp receive                         # poll once
signal-mcp receive --watch                 # keep watching (saves to store)

# Edit
signal-mcp edit +1234567890 <timestamp> "corrected text"
signal-mcp edit <group_id> <timestamp> "corrected text"

# React / delete / block
signal-mcp react +1234567890 <timestamp> +1234567890 👍
signal-mcp delete +1234567890 <timestamp>  # unsend a message you sent
signal-mcp block +1234567890               # and: signal-mcp unblock ...

# Pin / unpin / admin-delete messages
signal-mcp pin +1234567890 <timestamp> +1234567890
signal-mcp unpin +1234567890 <timestamp> +1234567890
signal-mcp admin-delete <group_id> <timestamp> +1234567890

# Devices
signal-mcp update-device <device_id> "My Laptop"

# Contacts & groups
signal-mcp contacts
signal-mcp contacts --json
signal-mcp find-contact anna               # add --all-recipients to include non-contacts (e.g. group members)
signal-mcp groups
signal-mcp group-label <group_id> "Anna"   # set YOUR OWN member label in a group
signal-mcp conversations                   # list all chats with unread count + last message

# History & search
signal-mcp history +1234567890
signal-mcp history +1234567890 --limit 20
signal-mcp history +1234567890 --limit 20 --offset 20   # page 2
signal-mcp history +1234567890 --since 2024-01-01
signal-mcp search "keyword"
signal-mcp search "keyword" --sender +1234567890   # restrict to one contact
signal-mcp search "keyword" --limit 20
signal-mcp search "invoice" --since 2024-01-01 --until 2024-02-01
signal-mcp store-stats

# Export
signal-mcp export                                          # all messages as JSON to stdout
signal-mcp export messages.json                            # save to file
signal-mcp export messages.csv --format csv                # CSV format
signal-mcp export --recipient +1234567890 --format csv     # one conversation
signal-mcp export --since 2024-01-01                       # messages from date

# Scheduled messages
signal-mcp schedule-send +1234567890 "Happy birthday!" --at "2027-01-01 09:00"
signal-mcp scheduled                       # list; cancel with: signal-mcp cancel-scheduled <id>
signal-mcp run-scheduled                   # send whatever is due now

# Stories & webhooks
signal-mcp story photo.jpg
signal-mcp set-webhook http://localhost:8080/signal   # run without a URL to clear
signal-mcp get-webhook

# Housekeeping
signal-mcp prune --days 180                # delete local messages older than 180 days

# Signal Desktop import — one-time full import
signal-mcp import-desktop
signal-mcp sync-desktop                    # incremental: only new messages since last sync

# Background service (macOS LaunchAgent or Linux systemd)
signal-mcp install-service    # auto-starts on login, captures all messages
signal-mcp uninstall-service

# MCP server (for Claude Code)
signal-mcp serve

Getting full message history

signal-cli only delivers new messages — it has no history API. Two ways to get history:

Going forward (captures everything from now on):

signal-mcp install-service   # background watcher, auto-starts on login

Retroactively (imports everything from Signal Desktop):

signal-mcp import-desktop    # macOS prompts for Keychain access; Linux needs an unlocked keyring

Run both for complete coverage.

Architecture

                    ┌─────────────────────────────────┐
                    │  signal-cli daemon  (:7583)      │
                    │  Signal protocol / libsignal     │
                    └──────────┬──────────────┬────────┘
                               │ sends/receives│
                    ┌──────────▼──────────┐   │ (when no service)
                    │  background service  │   │
                    │  LaunchAgent/systemd │   │
                    └──────────┬──────────┘   │
                               │ writes        │
                    ┌──────────▼──────────────▼────────┐
                    │  SQLite store                     │
                    │  ~/.local/share/signal-mcp/       │
                    │  messages.db  (FTS5 indexed)      │
                    └────────────────┬─────────────────┘
                                     │ reads/writes
                   ┌─────────────────┼─────────────────┐
                   │                 │                  │
        ┌──────────▼──────┐ ┌────────▼───────┐ ┌──────▼──────────┐
        │  Claude Code /  │ │  signal-mcp    │ │  signal-mcp CLI │
        │  Claude Desktop │ │  serve (MCP)   │ │  (terminal)     │
        │  (asks Claude)  │ └────────────────┘ └─────────────────┘
        └─────────────────┘

How it works:

get_unread is the primary "check for new messages" tool. If the background service is installed, it reads straight from the store (the service keeps it up to date). Otherwise it polls signal-cli first (debounced to once every 30 seconds) and includes a _warning suggesting signal-mcp install-service. list_conversations is a pure store read — fast, no polling.

The daemon starts automatically on first use. Attachments are saved to ~/Downloads/signal-attachments/.

signal-cli Coverage

signal-mcp wraps the signal-cli JSON-RPC daemon. Here's what is and isn't covered:

Covered (81 tools)

Plus tools with no direct signal-cli equivalent: get_conversation, search_messages, list_conversations, store_stats, import_desktop, sync_desktop, export_messages, mark_as_unread, clear_local_store, delete_local_messages, prune_store.

Not covered

These commands are deliberately excluded — either not feasible to implement as MCP tools, or consciously left out (see the reason for each):

Development

git clone https://github.com/googlarz/signal-mcp
cd signal-mcp
uv sync --dev
uv run pytest
uv run pytest --cov --cov-report=term-missing

573 tests, 100% line coverage across all modules. All tests are fully mocked — no signal-cli installation or Signal account required to run them.

See CONTRIBUTING.md for how to add new tools.

License

MIT — see LICENSE.