bundle-exec

Executes a command in the context of the Gemfile bundle using

SERVERCargo SOURCEDave-London/Pare

High RISK CLASS

Category Execute

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-github-dave-london-cargo/bundle-exec.md

WHAT IT DOES

What bundle-exec does on Cargo

AI agents invoke bundle-exec to trigger actions in Cargo. 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.

RISK

Why bundle-exec is rated High

bundle-exec runs arbitrary shell commands in the Gemfile bundle context, meaning an AI agent could execute any code available in the bundle. This is an Execute category with high severity due to the broad command execution capability.

From the tool's definition 'Executes a command in the context of the Gemfile bundle' — runs arbitrary commands within the bundle environment

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs bundle-exec safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Cargo, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For bundle-exec, this is the rule to start with:

bundle-exec Rate-limited

bundle-exec 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": {
    "bundle-exec": {
      "limits": [
        {
          "counter": "bundle-exec_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Cargo, apply this rule, and every bundle-exec call is checked against it from then on.

FAQ

Questions about bundle-exec

What does the bundle-exec tool do? +

Executes a command in the context of the Gemfile bundle using. It is categorised as a Execute tool in the Cargo MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on bundle-exec? +

Register the Cargo MCP server in PolicyLayer and add a rule for bundle-exec: 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 Cargo. Nothing to install.

What risk level is bundle-exec? +

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

Can I rate-limit bundle-exec? +

Yes. Add a rate_limit block to the bundle-exec 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 bundle-exec completely? +

Set action: deny in the PolicyLayer policy for bundle-exec. 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 bundle-exec? +

bundle-exec is provided by the Cargo MCP server (Dave-London/Pare). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

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Guides

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