set_killswitch · Mullvad MCP: Risk & Policy

WHAT IT DOES

What set_killswitch does on Mullvad

AI agents use set_killswitch to create or update resources in Mullvad — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Mullvad environment.

WHY IT NEEDS A POLICY

Why set_killswitch needs a policy

This tool modifies a VPN security setting (kill switch/lockdown mode) that controls whether internet traffic is blocked when the VPN drops. Toggling it is reversible (Write), but misuse has high blast radius: disabling it could expose all traffic if VPN drops, while enabling it could cut off all internet connectivity.

From the tool's definition Enable or disable the kill switch (lockdown mode)

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_killswitch Rate-limited

set_killswitch stays usable, but capped — an agent stuck in a loop can't make hundreds of changes 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_killswitch": {
      "limits": [
        {
          "counter": "set_killswitch_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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Instant setup, no code required.

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

FAQ

Questions about set_killswitch

What does the set_killswitch tool do? +

Enable or disable the kill switch (lockdown mode). It is categorised as a Write tool in the Mullvad MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on set_killswitch? +

Register the Mullvad MCP server in PolicyLayer and add a rule for set_killswitch: 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 Mullvad. Nothing to install.

What risk level is set_killswitch? +

set_killswitch is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit set_killswitch? +

Yes. Add a rate_limit block to the set_killswitch 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_killswitch completely? +

Set action: deny in the PolicyLayer policy for set_killswitch. 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_killswitch? +

set_killswitch is provided by the Mullvad MCP server (oresam-xyz/mullvad-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.