d2

d2 is an MCP server for Claude Code, Codex, Cursor, Gemini CLI, OpenCode from h0rv/d2-mcp. Its token cost is not measured, scanned A, original, MIT.

A local tool connection for d2-mcp, a service that works with D2 diagram source. It starts the service over standard input and output so an agent can call its diagram operations.

In plain words
What is it for?
Use it when an agent needs to send D2 source to the d2-mcp service for diagram validation or rendering. The configuration starts the service with its standard command and transport.
Why use it?
It provides the connection needed by D2 workflows to compile or render diagrams. Without this connection, those operations cannot be performed.

MCP server for Claude CodeCodexCursorGemini CLIOpenCode

Written for Claude Code: shipped in a Claude Code plugin. Also seen: listed in a Claude config.

Part of the d2 plugin — 1 skill, 1 MCP server shipped together

Good fit Use it when an agent needs to send D2 source to the d2-mcp service for diagram validation or rendering. The configuration starts the service with its standard command and transport.

Compare 6 mcp servers from other repositories ↓
Install with agentmods
npx agentmods add mcp/h0rv/d2-mcp/package-d2

Installing this writes the configuration, not the program: `d2-mcp` has to be on your PATH already, or the server will not start.

View source ↗ h0rv/d2-mcp
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo
git clone --depth 1 https://github.com/h0rv/d2-mcp

Installing this writes the configuration, not the program: `d2-mcp` has to be on your PATH already, or the server will not start.

Made for: Claude Code, Codex, Cursor, Gemini CLI, OpenCode.

Or install d2, the plugin that ships this one along with the rest of its 1 skill, 1 MCP server.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for d2

README.md
[![agentmods](https://agentmods.dev/badge/mcp/h0rv/d2-mcp/package-d2/github.svg)](https://agentmods.dev/mcp/h0rv/d2-mcp/package-d2)
Your own site
<a href="https://agentmods.dev/mcp/h0rv/d2-mcp/package-d2"><img src="https://agentmods.dev/badge/mcp/h0rv/d2-mcp/package-d2/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for d2

Your own site · 80×15
<a href="https://agentmods.dev/mcp/h0rv/d2-mcp/package-d2"><img src="https://agentmods.dev/badge/mcp/h0rv/d2-mcp/package-d2.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session not measured What this adds to a session before it is invoked.
When invoked not measured Not applicable: nothing here is loaded into a session.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Security

Grade A, and why

d2 scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

agents/package/.mcp.json · 10 lines

What it actually says

{
  "d2": {
    "type": "stdio",
    "command": "d2-mcp",
    "args": [
      "--transport",
      "stdio"
    ]
  }
}
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 10 lines scan A 39a872b46cc4

Subscribe to this mod's changes

d2 is an MCP server published in the GitHub repository h0rv/d2-mcp (22 stars, last pushed today), licensed MIT. Its token cost is not measured: an MCP server costs its tool schemas, not its config file. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-10-13.

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