bundle-exec

Executes a command in the context of the Gemfile bundle using

SERVERBuild 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-build/bundle-exec.md

WHAT IT DOES

What bundle-exec does on Build

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

The tool explicitly 'executes a command', meaning it runs arbitrary commands within the Ruby bundle context. This is a general command execution primitive whose effects are entirely determined by the arguments passed, making it Execute category with high severity due to the potential blast radius of arbitrary command execution.

From the tool's definition Executes a command in the context of the Gemfile bundle using

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 Build, 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 Build, 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 Build 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 Build 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 Build. 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 Build 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

More on Build, and thousands of servers like it.

This server

All 202 Build tools → High-risk tools on this server →

Across the catalogue

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Guides

Govern code and CI agents →Agent sandbox →Least privilege for MCP →