simplisafe-mcp

MCP server for SimpliSafe home security. Check whether the system is armed, review sensors and events, arm/disarm, and control smart locks — from Claude.

This server can disarm a home alarm and unlock doors. Every tool that changes physical state, plus the tool that reads alarm PINs, asks you to confirm first — nothing is sent until you do, and you see a preview of exactly what would happen (see Confirmations). Install it only where you'd be comfortable with that capability.

Developed and maintained by AI (Claude Code).

What you get

Supports SimpliSafe 3 systems. Legacy SS2 systems are rejected with an explanation rather than an opaque upstream 404.

Related MCP server: mcp-hs4

Install

npm install -g simplisafe-mcp

Or add to .mcp.json:

{
  "mcpServers": {
    "simplisafe": {
      "command": "npx",
      "args": ["-y", "simplisafe-mcp"],
      "env": { "SIMPLISAFE_REFRESH_TOKEN": "${SIMPLISAFE_REFRESH_TOKEN}" }
    }
  }
}

Authentication — one browser login, once

SimpliSafe issues no API keys. The credential is an OAuth2 refresh token, minted by a browser login you perform one time:

git clone https://github.com/chrischall/simplisafe-mcp && cd simplisafe-mcp
node scripts/bootstrap-auth.mjs             # prints an authorize URL
# sign in (MFA included), then copy the com.simplisafe.mobile:// URL
node scripts/bootstrap-auth.mjs "<that URL>"

The token is written to .env (mode 0600) after being verified against the live API. SimpliSafe does not rotate refresh tokens, so it stays valid until you sign out of all devices in the SimpliSafe app — which is how you revoke it.

Capturing the code: open DevTools → Network and tick Preserve log before signing in; afterwards the browser fails to open a com.simplisafe.mobile://… link, and that failed entry's link address is what you paste. The code is single-use and expires in about two minutes.

Treat the resulting token like a house key: it grants full control of the alarm.

Confirmations

Arming, disarming, locking, unlocking and reading the PINs all ask you to confirm first. On a client that can show a confirmation prompt (Claude Code) you get the prompt, with the details below (unless MCP_CONFIRM_ELICITATION=off). On one that cannot (claude.ai, Claude Desktop) the first call sends nothing and returns a preview plus a confirmToken; only a repeat call with that token acts, once. The preview includes a plain statement of the physical consequence:

{
  "status": "confirmation-required",
  "confirmed": false,
  "dispatched": false,
  "action": "alarm.set_state",
  "preview": {
    "action": "set alarm state to away",
    "method": "POST",
    "path": "/ss3/subscriptions/7858153/state/away",
    "sid": 7858153,
    "locationName": "Home",
    "currentState": "OFF",
    "requestedState": "AWAY",
    "warning": "Arms ALL sensors including interior motion. Starts an exit delay; anyone still moving inside when it expires can trigger the siren and a monitoring-center dispatch."
  },
  "confirmToken": "…",
  "expiresAt": "…",
  "ttlSeconds": 600,
  "instruction": "Show this preview to the user verbatim and proceed only after they explicitly approve in chat. Then call again with confirmToken."
}

The token is bound to that tool, target and preview. The system is re-read on the second call, and if what would happen no longer matches what you approved — different arguments, or the alarm or lock state moved in between — it is refused (DRAFT_CHANGED) with a fresh preview. A token that was already used is refused too (TOKEN_REUSED).

Writes are verified

Once confirmed, a write executes and then re-reads the system to check what actually happened, reporting confirmed, in_progress (the exit delay is counting down), or unconfirmed. A 2xx is never treated as proof.

Shell access without the server

For quick one-off queries there's a curl-based skill in skills/simplisafe-api/ — same API, no MCP process, sharing the same refresh token.

Development

npm install
npm run build
npm test

Verified endpoint shapes live in docs/SIMPLISAFE-API.md, including several things that are easy to get backwards:

• lock state is encoded 1 = locked, 2 = unlocked;

• system version for routing is at location.system.version, not the top-level systemVersion;

• events and doorlock control are not under the ss3/ prefix;

• numEvents has an undocumented hard ceiling of 50;

• settings.pins returns alarm codes in cleartext alongside harmless settings.

Disclaimer

Unofficial. Not affiliated with or endorsed by SimpliSafe. It uses the same private API the SimpliSafe mobile app uses, with your own account credentials. Use at your own discretion.

License

MIT