High Risk →

esbuild

Runs the esbuild bundler and returns structured errors, warnings, and output files.

How to control esbuild ↓

What esbuild does on Make

AI agents invoke esbuild to trigger actions in Make. 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.

High Risk

Why esbuild needs a policy

This tool runs the esbuild bundler, which executes a build process that can compile, transform, and bundle arbitrary code files. An AI agent could misuse this to process malicious scripts or trigger unintended build operations. The 'runs' keyword confirms active execution of an external tool, placing it firmly in the Execute category.

From the tool's definition 'Runs the esbuild bundler' — explicitly executes an external build/bundling process

Documented attack patterns abuse exactly the kind of access esbuild gives an agent:

How to control esbuild

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

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "esbuild": {
      "limits": [
        {
          "counter": "esbuild_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

esbuild 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.

  1. Create a free account and register Make — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
RATE-LIMIT THIS TOOL →

Free to start. No card required.

Related tools and policies

Go deeper

Questions about esbuild

What does the esbuild tool do? +

Runs the esbuild bundler and returns structured errors, warnings, and output files. It is categorised as a Execute tool in the Make MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on esbuild? +

Register the Make MCP server in PolicyLayer and add a rule for esbuild: 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 Make. Nothing to install.

What risk level is esbuild? +

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

Can I rate-limit esbuild? +

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

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

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

Enforce policy on every Make tool call.

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

Free to start. No card required.

202 Make tools catalogued and risk-classified — across an index of 43,000+ MCP servers.

// GET IN TOUCH

Have a question or want to learn more? Send us a message.

Message sent.

We'll get back to you soon.