pnpm_install · Promethean OS MCP: Risk & Policy

WHAT IT DOES

What pnpm_install does on Promethean OS MCP

AI agents invoke pnpm_install to trigger actions in Promethean OS MCP. 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 pnpm_install needs a policy

This tool executes the pnpm package manager to install dependencies. It runs an external shell command that modifies the filesystem (node_modules, lockfiles) and can trigger lifecycle scripts (postinstall hooks), making it an Execute-category action. Misuse could introduce malicious packages or trigger arbitrary code via install scripts.

From the tool's definition "Run pnpm install at the workspace root or limited to filtered packages"

Risk signalsAdmin/system-level operation

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

pnpm_install Rate-limited

pnpm_install 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": {
    "pnpm_install": {
      "limits": [
        {
          "counter": "pnpm_install_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 Promethean OS MCP, so you can run agents against it safely.

FAQ

Questions about pnpm_install

What does the pnpm_install tool do? +

Run pnpm install at the workspace root or limited to filtered packages. It is categorised as a Execute tool in the Promethean OS MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on pnpm_install? +

Register the Promethean OS MCP server in PolicyLayer and add a rule for pnpm_install: 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 Promethean OS MCP. Nothing to install.

What risk level is pnpm_install? +

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

Can I rate-limit pnpm_install? +

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

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

pnpm_install is provided by the Promethean OS MCP server (octave-commons/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.