nvm_alias · NVM MCP Server MCP: Risk & Policy

WHAT IT DOES

What nvm_alias does on NVM MCP Server

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

WHY IT NEEDS A POLICY

Why nvm_alias needs a policy

This tool modifies NVM alias mappings, which are persistent configuration changes affecting how Node.js versions are resolved in the environment. While not irreversible (aliases can be changed or removed), the impact is significant because a malicious agent could create misleading aliases (e.g., aliasing 'default' to an old vulnerable Node version) that could affect all downstream development workflows and CI/CD…

From the tool's definition Tool name 'nvm_alias' and description 'Create or update an NVM alias' directly indicate the tool creates or modifies NVM configuration state. The verbs 'create' and 'update' are hallmarks of Write operations.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

nvm_alias Rate-limited

nvm_alias 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": {
    "nvm_alias": {
      "limits": [
        {
          "counter": "nvm_alias_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 NVM MCP Server, so you can run agents against it safely.

FAQ

Questions about nvm_alias

What does the nvm_alias tool do? +

Create or update an NVM alias. It is categorised as a Write tool in the NVM MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on nvm_alias? +

Register the NVM MCP Server MCP server in PolicyLayer and add a rule for nvm_alias: 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 NVM MCP Server. Nothing to install.

What risk level is nvm_alias? +

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

Can I rate-limit nvm_alias? +

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

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

nvm_alias is provided by the NVM MCP Server MCP server (realjacoblinder/nvm-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.