render

SERVEREmailmd SOURCEemailmd

High RISK CLASS

Category Execute

Parameters 31 required

Recommended Rate-limitedsee the rule below

Registry record Grade D, identity unverified Pull the record →

This record as markdown: /tools/dev-emailmd-emailmd/render.md

WHAT IT DOES

What render does on Emailmd

AI agents invoke render to trigger actions in Emailmd. 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.

Parameter	Type	Required	Description
`minify`	boolean	—	Minify the HTML. Recommended for sending; helps stay under Gmail's 102KB clip limit.
`markdown`	string	Yes	The emailmd markdown document, optionally starting with YAML frontmatter.
`partials`	object	—	Named markdown partials spliced in wherever the document says "::: include <name>".

Parameters from the server's own tool schema.

RISK

Why render is rated High

render triggers real processes with real consequences. An agent gone sideways doesn't fire it once. It starts dozens of builds, sends mass notifications, or burns through compute before anyone looks up.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs render safely

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

render Rate-limited

render 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": {
    "render": {
      "limits": [
        {
          "counter": "render_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 Emailmd, apply this rule, and every render call is checked against it from then on.

FAQ

Questions about render

What does the render tool do? +

Render emailmd markdown into email-safe HTML. Returns html (the complete email document), text (the plain-text MIME part), meta (frontmatter), warnings (non-fatal repairs made while rendering; aim for none), htmlBytes, and previewUrl (a live browser preview of this exact document to share with the user). It is categorised as a Execute tool in the Emailmd MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

What parameters does render accept? +

render accepts 3 parameters: minify, markdown, partials. Required: markdown. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on render? +

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

What risk level is render? +

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

Can I rate-limit render? +

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

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

render is provided by the Emailmd MCP server (emailmd). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

More on Emailmd, and thousands of servers like it.

This server

All 3 Emailmd tools → High-risk tools on this server →

Across the catalogue

All high-risk MCP tools → The MCP Attack Database →

Guides

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