Dgmo

Turn a conversation into a real diagram — without leaving your AI tool.

npm version npm downloads license

This MCP server gives Claude (and any MCP-compatible AI tool) the ability to render sequence diagrams, flowcharts, ER diagrams, C4 architecture, gantt charts, and 35+ other chart types from concise text markup — then hand the result off to a full editor for refinement. Ask for a diagram in chat; get a real one back.

What you can do

Ask in plain language — "diagram the auth flow as a sequence", "chart the Q3 plan as a gantt", "draw our services as a C4 diagram" — and Claude writes the markup and renders it. The markup stays readable and diffable:

flowchart Mutiny Resolution
direction-tb

[Sail]     Set sail under the captain
{Trouble?} Discontent in the crew?
{Vote}     Crew vote called
[Mutiny]   Seize the ship

(Sail) -> (Trouble?)
(Trouble?) -Yes-> (Vote)
(Vote) -Mutiny-> (Mutiny)

→ renders to the flowchart above. All rendering happens locally — no diagram data leaves your machine.

Tools

Tool	What it does
render_diagram	Render DGMO markup to SVG or PNG
preview_diagram	Render one or more diagrams and open an HTML preview in the browser
generate_report	Build a polished multi-section HTML report with ToC and optional source
list_chart_types	List all supported chart types
get_language_reference	Get DGMO syntax documentation for accurate generation
share_diagram	Get a shareable diagrammo.app URL — hand your diagram to the web editor
open_in_app	Open the diagram straight into the Diagrammo desktop app for editing

The last two are the bridge out of chat: a diagram Claude generates becomes something you can refine, restyle, and embed — see below.

Beyond the MCP server

The MCP server is one entry point into Diagrammo — a whole ecosystem built on the same DGMO markup. Generate in chat, refine in a real editor, embed anywhere:

• diagrammo.app — the desktop app. open_in_app drops an AI-generated diagram straight into it, with live preview, palettes, and export.
• online.diagrammo.app — a full editor in the browser, zero install. share_diagram URLs open right here.
• Docs integrations — drop DGMO fenced code blocks into your docs site: remark-dgmo, astro-dgmo, docusaurus-plugin-dgmo, fumadocs-dgmo.
• Obsidian — the Diagrammo Diagrams community plugin renders DGMO in your vault.
• CLI — npx @diagrammo/dgmo file.dgmo -o out.png, or install via Homebrew.

One markup, everywhere. A diagram you generate here renders identically in the app, in your docs, and in Obsidian — because they all speak DGMO.

→ Try it free at diagrammo.app

Setup

Claude Code

Add to your project's .claude/settings.local.json (or run npx @diagrammo/dgmo --install-claude-code-integration to do it automatically):

{
  "mcpServers": {
    "dgmo": {
      "command": "npx",
      "args": ["-y", "@diagrammo/dgmo-mcp"]
    }
  }
}

Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "dgmo": {
      "command": "npx",
      "args": ["-y", "@diagrammo/dgmo-mcp"]
    }
  }
}

Restart Claude Desktop after saving — the tools appear automatically.

Privacy

All rendering is local. Your diagram markup and the images it produces never leave your machine, except when you explicitly call share_diagram (which encodes the diagram into a diagrammo.app URL). See the privacy terms.

Contributing & releases

Development setup and the release workflow live in CONTRIBUTING.md.

License

MIT