proxmox_start_vm · Homelab MCP: Risk & Policy

WHAT IT DOES

What proxmox_start_vm does on Homelab

AI agents invoke proxmox_start_vm to trigger actions in Homelab. 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 proxmox_start_vm needs a policy

Starting a VM or LXC container is an execution action that triggers external operations on the homelab infrastructure. While not destructive or financial, it exercises control over compute resources and could impact system availability or services depending on which VM/container is started. The blast radius is high in a homelab context where misconfiguration or malicious use could disrupt multiple dependent services.

From the tool's definition Tool name 'proxmox_start_vm' and description 'Start a VM or LXC container by its VMID' indicate triggering an external operation (VM/container startup) whose effects depend on the VMID argument provided.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

proxmox_start_vm Rate-limited

proxmox_start_vm 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": {
    "proxmox_start_vm": {
      "limits": [
        {
          "counter": "proxmox_start_vm_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 Homelab, so you can run agents against it safely.

FAQ

Questions about proxmox_start_vm

What does the proxmox_start_vm tool do? +

Start a VM or LXC container by its VMID. It is categorised as a Execute tool in the Homelab MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on proxmox_start_vm? +

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

What risk level is proxmox_start_vm? +

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

Can I rate-limit proxmox_start_vm? +

Yes. Add a rate_limit block to the proxmox_start_vm 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 proxmox_start_vm completely? +

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

proxmox_start_vm is provided by the Homelab MCP server (nainounen/homelab-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.