set_lock_state · Nuki MCP: Risk & Policy

WHAT IT DOES

What set_lock_state does on Nuki

AI agents invoke set_lock_state to trigger actions in Nuki. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why set_lock_state needs a policy

This tool controls a physical smart lock, either locking or unlocking a door. While it is technically reversible (you can re-lock or re-unlock), the real-world consequences of misuse are critical: an attacker or misbehaving agent could unlock a door, granting unauthorized physical access to a home or premises.

From the tool's definition 'Lock or unlock a Nuki device' — triggers a physical external operation (engaging or disengaging a door lock mechanism)

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_lock_state Rate-limited

set_lock_state stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "set_lock_state": {
      "limits": [
        {
          "counter": "set_lock_state_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Nuki, so you can run agents against it safely.

FAQ

Questions about set_lock_state

What does the set_lock_state tool do? +

Lock or unlock a Nuki device. It is categorised as a Execute tool in the Nuki MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on set_lock_state? +

Register the Nuki MCP server in PolicyLayer and add a rule for set_lock_state: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Nuki. Nothing to install.

What risk level is set_lock_state? +

set_lock_state is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit set_lock_state? +

Yes. Add a rate_limit block to the set_lock_state rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block set_lock_state completely? +

Set action: deny in the PolicyLayer policy for set_lock_state. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides set_lock_state? +

set_lock_state is provided by the Nuki MCP server (sandraschi/nuki-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.