High Risk →

builder

Build profile. May edit source and test files but not config,

Part of the Cortex server.

builder can trigger actions in Cortex, with no limits today. PolicyLayer puts allow, deny, and rate-limit rules on every call. Live in minutes.

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Free to start. No card required.

AI agents invoke builder to trigger processes or run actions in Cortex. Execute operations can have side effects beyond the immediate call -- triggering builds, sending notifications, or starting workflows. Rate limits and argument validation are essential to prevent runaway execution.

builder can trigger processes with real-world consequences. An uncontrolled agent might start dozens of builds, send mass notifications, or kick off expensive compute jobs. PolicyLayer enforces rate limits and validates arguments to keep execution within safe bounds.

Execute tools trigger processes. Rate-limit and validate arguments to prevent unintended side effects.

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

See the full Cortex policy for all 32 tools.

Get this rule live on your own Cortex server in minutes. PolicyLayer enforces it on every call, before it runs.

ENFORCE ON MY CORTEX →

View all 32 tools →

These attack patterns abuse exactly the kind of access builder gives an agent. Each links to the full case and the policy that stops it:

Browse the full MCP Attack Database →

Every attack above starts with a tool call. PolicyLayer checks each one against your policy first, so builder only ever does what you allow.

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Other execute tools across the catalogue. The same approach applies to each: rate-limit and validate the arguments.

What does the builder tool do? +

Build profile. May edit source and test files but not config,. It is categorised as a Execute tool in the Cortex MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on builder? +

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

What risk level is builder? +

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

Can I rate-limit builder? +

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

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

builder is provided by the Cortex MCP server (@danielblomma/cortex-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Cortex tool call.

Deterministic rules across all 32 Cortex tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.

Free to start. No card required.

4,600+ MCP servers and 31,000+ tools scanned and risk-classified.

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