npm_update_dead_host · Nginx Manager MCP: Risk & Policy

WHAT IT DOES

What npm_update_dead_host does on Nginx Manager

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

WHY IT NEEDS A POLICY

Why npm_update_dead_host needs a policy

This tool modifies an existing dead host (404 host) configuration in Nginx Proxy Manager. Updates are reversible changes to infrastructure configuration. While it affects proxy behavior, it does not delete data (would be Destructive) or execute arbitrary code (would be Execute).

From the tool's definition Tool name contains 'update' and description states 'Update a 404 host', indicating modification of existing configuration data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

npm_update_dead_host Rate-limited

npm_update_dead_host 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": {
    "npm_update_dead_host": {
      "limits": [
        {
          "counter": "npm_update_dead_host_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about npm_update_dead_host

What does the npm_update_dead_host tool do? +

Update a 404 host. It is categorised as a Write tool in the Nginx Manager MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on npm_update_dead_host? +

Register the Nginx Manager MCP server in PolicyLayer and add a rule for npm_update_dead_host: 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 Nginx Manager. Nothing to install.

What risk level is npm_update_dead_host? +

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

Can I rate-limit npm_update_dead_host? +

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

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

npm_update_dead_host is provided by the Nginx Manager MCP server (kognar-ai/ngnix-manager-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.