compile_mjml · MJML MCP Server MCP: Risk & Policy

WHAT IT DOES

What compile_mjml does on MJML MCP Server

AI agents invoke compile_mjml to trigger actions in MJML MCP Server. 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.

WHY IT NEEDS A POLICY

Why compile_mjml needs a policy

This is an Execute category tool because it runs a compilation operation on user-provided MJML markup. While the immediate output is HTML (not destructive or financial), compilation inherently processes and transforms code, which is a form of execution.

From the tool's definition 'Compile MJML to HTML' indicates executing a compilation process that transforms markup into executable HTML output. The tool processes user-supplied input and generates output code.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

compile_mjml Rate-limited

compile_mjml 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": {
    "compile_mjml": {
      "limits": [
        {
          "counter": "compile_mjml_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches MJML MCP Server, so you can run agents against it safely.

FAQ

Questions about compile_mjml

What does the compile_mjml tool do? +

Compile MJML to HTML with various options. It is categorised as a Execute tool in the MJML MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on compile_mjml? +

Register the MJML MCP Server MCP server in PolicyLayer and add a rule for compile_mjml: 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 MJML MCP Server. Nothing to install.

What risk level is compile_mjml? +

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

Can I rate-limit compile_mjml? +

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

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

compile_mjml is provided by the MJML MCP Server MCP server (shaunie2fly/mjml_mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.