pyodide_install-packages

THE RISK

High Risk

Why pyodide_install-packages needs a policy

Installing packages modifies the runtime environment by fetching and installing external code. This is an Execute-category action because it triggers external operations (downloading and installing packages) that affect the execution environment. It could be misused to install malicious packages or alter the environment in ways that affect subsequent code execution.

From the tool's definition Install Python packages using Pyodide

Documented attack patterns abuse exactly the kind of access pyodide_install-packages gives an agent:

POLICY

How to control pyodide_install-packages

PolicyLayer is an MCP gateway — it sits between your AI agents and Mcp Pyodide, and nothing reaches the server without passing your rules. This is the rule we recommend for pyodide_install-packages:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "pyodide_install-packages": {
      "limits": [
        {
          "counter": "pyodide_install-packages_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

pyodide_install-packages 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.

Create a free account and register Mcp Pyodide — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

RATE-LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Mcp Pyodide tools

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All 5 Mcp Pyodide tools →

Execute tools on other servers

Android Forensics ADB MCP Server adb_shell_command EMBA-MCP run_emba_scan Frida Game Hacking MCP remove_breakpoint Procmon request_elevation

Go deeper

High-risk tools in Mcp Pyodide → Every high-risk tool this server exposes, in one view.
All high-risk MCP tools → Every high-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Agent sandbox → Bounding what an agent can execute and where the boundary should sit.
Least privilege for MCP → Granting agents the minimum tool surface the task needs.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about pyodide_install-packages

What does the pyodide_install-packages tool do? +

Install Python packages using Pyodide. Multiple packages can be specified using space-separated format. It is categorised as a Execute tool in the Mcp Pyodide MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on pyodide_install-packages? +

Register the Mcp Pyodide MCP server in PolicyLayer and add a rule for pyodide_install-packages: 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 Mcp Pyodide. Nothing to install.

What risk level is pyodide_install-packages? +

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

Can I rate-limit pyodide_install-packages? +

Yes. Add a rate_limit block to the pyodide_install-packages 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 pyodide_install-packages completely? +

Set action: deny in the PolicyLayer policy for pyodide_install-packages. 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 pyodide_install-packages? +

pyodide_install-packages is provided by the Mcp Pyodide MCP server (yonaka15/mcp-pyodide). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Mcp Pyodide tool call.

Start from Mcp Pyodide, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →