add_nfproxy_service · Firegex MCP: Risk & Policy

WHAT IT DOES

What add_nfproxy_service does on Firegex

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

WHY IT NEEDS A POLICY

Why add_nfproxy_service needs a policy

This tool creates a new service registration in a firewall/proxy system (nfproxy). While not destructive (reversible via delete_nfproxy_service), it modifies the firewall's operational configuration by adding network-facing proxy services. This is a Write operation.

From the tool's definition add_nfproxy_service registers a new service in the firewall infrastructure, creating a new proxy configuration that persists in the system state. The verb 'add' indicates creation/modification of data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_nfproxy_service Rate-limited

add_nfproxy_service 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": {
    "add_nfproxy_service": {
      "limits": [
        {
          "counter": "add_nfproxy_service_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 Firegex, so you can run agents against it safely.

FAQ

Questions about add_nfproxy_service

What does the add_nfproxy_service tool do? +

Register a new nfproxy service. proto is 'tcp' or 'http'. It is categorised as a Write tool in the Firegex MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on add_nfproxy_service? +

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

What risk level is add_nfproxy_service? +

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

Can I rate-limit add_nfproxy_service? +

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

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

add_nfproxy_service is provided by the Firegex MCP server (umbra2728/firegex-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.