--- slug: "drawio-mcp" source_type: "readme" source_url: "https://cdn.jsdelivr.net/gh/jgraph/drawio-mcp@main/README.md" repo: "https://github.com/jgraph/drawio-mcp" source_file: "README.md" branch: "main" --- # Draw.io MCP Server The official [draw.io](https://www.draw.io) MCP (Model Context Protocol) server that enables LLMs to create and open diagrams in the draw.io editor. ## Four Ways to Create Diagrams This repository offers four approaches for integrating draw.io with AI assistants. Pick the one that fits your setup: | | [MCP App Server](#mcp-app-server) | [MCP Tool Server](#mcp-tool-server) | [Assistant Plugins](#assistant-plugins-claude-code-codex-cli) | [Project Instructions](#alternative-project-instructions-no-mcp-required) | |---|---|---|---|---| | **How it works** | Renders diagrams inline in chat | Opens diagrams in your browser | Generates `.drawio` files, optional PNG/SVG/PDF export or browser URL | Claude generates draw.io URLs via Python | | **Diagram output** | Interactive viewer embedded in conversation | draw.io editor in a new tab | `.drawio`, `.drawio.png` / `.svg` / `.pdf`, or browser URL | Clickable link to draw.io | | **Requires installation** | No (hosted at `mcp.draw.io`) | Yes (npm package) | One-line plugin install (draw.io Desktop only for PNG/SVG/PDF export) | No — just paste instructions | | **Supports XML, CSV, Mermaid** | XML only | ✅ All three | XML only (native format) | ✅ All three | | **Editable in draw.io** | Via "Open in draw.io" button | ✅ Directly | ✅ Directly | Via link | | **Works with** | Claude.ai, VS Code, Cursor, any MCP Apps host | Claude Desktop, Cursor, any MCP client | Claude Code, Codex CLI | Claude.ai (with Projects) | | **Best for** | Inline previews in chat | Local desktop workflows | Local development workflows | Quick setup, no install needed | --- ## MCP App Server The MCP App server renders draw.io diagrams **inline** in AI chat interfaces using the [MCP Apps](https://modelcontextprotocol.io/docs/extensions/apps) protocol. Instead of opening a browser tab, diagrams appear directly in the conversation as interactive iframes. The official hosted endpoint is available at: ``` https://mcp.draw.io/mcp ``` Add this URL as a remote MCP server in Claude.ai, Cursor, or any MCP Apps-compatible host — no installation required. In Cursor (≥ 2.6), diagrams render inline in the Agent chat ([one-click install](https://cursor.com/en/install-mcp?name=drawio&config=eyJ1cmwiOiJodHRwczovL21jcC5kcmF3LmlvL21jcCJ9)); on older builds, use the stdio [`@drawio/mcp`](https://github.com/jgraph/drawio-mcp/blob/HEAD/mcp-tool-server/README.md) tool server instead. You can also run the server locally via Node.js or deploy your own instance to Cloudflare Workers. **Tools:** - **`create_diagram`** — Renders draw.io XML as an interactive diagram inline in chat - **`search_shapes`** — Searches 10,000+ shapes across all draw.io libraries (AWS, Azure, GCP, P&ID, electrical, Cisco, Kubernetes, UML, BPMN, etc.) by keyword, supplemented by the draw.io icon service (brand logos and general-purpose concept icons) when the built-in libraries have no good match. Returns exact style strings that can be used directly in XML. Use this to find the correct shape before calling `create_diagram`. **[Full documentation →](https://github.com/jgraph/drawio-mcp/blob/HEAD/mcp-app-server/README.md)** > **Note:** Inline diagram rendering requires an MCP host that supports the MCP Apps extension. In hosts without MCP Apps support, the tool still works but returns the XML as text. --- ## MCP Tool Server The original MCP server that opens diagrams directly in the draw.io editor. Supports XML, CSV, and Mermaid.js formats with lightbox and dark mode options. Published as [`@drawio/mcp`](https://www.npmjs.com/package/@drawio/mcp) on npm. Quick start: `npx @drawio/mcp` Setup instructions are available for Claude Desktop, Claude Code, VS Code (GitHub Copilot), and Cursor (with one-click install). **[Full documentation →](https://github.com/jgraph/drawio-mcp/blob/HEAD/mcp-tool-server/README.md)** --- ## Assistant Plugins (Claude Code, Codex CLI) The `drawio` skill packaged as a plugin for AI coding assistants (under [`plugins/`](https://github.com/jgraph/drawio-mcp/blob/HEAD/plugins/README.md)): it generates native `.drawio` files, with optional export to PNG, SVG, or PDF (with embedded XML so the exported file remains editable in draw.io) — or a browser URL that opens the diagram directly in `app.diagrams.net`. No MCP setup required. The same skill ships for two hosts: **Claude Code** ([full documentation →](https://github.com/jgraph/drawio-mcp/blob/HEAD/plugins/claude-code/README.md)) — install from this repo's marketplace: ``` /plugin marketplace add jgraph/drawio-mcp /plugin install drawio@drawio ``` Or load it directly from a local clone with `claude --plugin-dir ./plugins/claude-code`. **Codex CLI** ([full documentation →](https://github.com/jgraph/drawio-mcp/blob/HEAD/plugins/codex/drawio/README.md)) — install from the same marketplace repo: ```bash codex plugin marketplace add jgraph/drawio-mcp codex plugin add drawio@drawio ``` By default, the plugin writes a `.drawio` file and opens it in draw.io. Mention a format in your request to change the output: - `/drawio:drawio png ...` / `svg` / `pdf` — exports using the draw.io desktop CLI with `--embed-diagram` - `/drawio:drawio url ...` — compresses the XML with Node.js's built-in `zlib` and opens the result at `app.diagrams.net`. No draw.io Desktop needed; the `.drawio` file is kept locally as a persistent copy. --- ## Alternative: Project Instructions (No MCP Required) An alternative approach that works **without installing anything**. Add instructions to a Claude Project that teach Claude to generate draw.io URLs using Python code execution. No MCP server, no desktop app — just paste and go. **[Full documentation →](https://github.com/jgraph/drawio-mcp/blob/HEAD/project-instructions/README.md)** --- ## Diagram layouts Two optional, independent layout passes can run after the AI generates a diagram — one re-arranges the nodes, the other only reroutes the edges. Which are available depends on the approach: | Layout pass | What it does | App Server (`create_diagram`) | Tool Server (`open_drawio_xml`) | Assistant Plugins | Project Instructions | |---|---|---|---|---|---| | **ELK auto-layout** (`postLayout: "elk"`) | Re-arranges nodes into a clean layered layout; routes the edges as part of it | ✅ | — | ✅ via draw.io Desktop CLI (`--layout`) | — | | **libavoid routing** (`routing: "libavoid"`) | Keeps node positions; reroutes connectors orthogonally *around* the shapes | ✅ | ✅ from **v1.3.0** | ✅ via draw.io Desktop CLI (`--layout libavoid`) | — | - These apply to **draw.io XML** diagrams. **Mermaid** diagrams are auto-laid-out already, so neither pass is needed. - The **App Server** applies these in the inline viewer after the diagram renders; the **Tool Server** applies libavoid server-side before opening the draw.io editor; the **plugins** run them through the locally installed draw.io Desktop CLI. - Pick one, not both: ELK already routes its own edges, so adding libavoid on top is redundant. Use `postLayout` to re-arrange a layout, or `routing` to tidy the connectors on a layout you placed deliberately. --- ## Data Residency & Offline Use If you're deploying in an environment with strict data restrictions, here is exactly where diagram data goes for each approach. **No component sends your diagram to a cloud rasterizer.** `convert.diagrams.net` (or any cloud export endpoint) is not called anywhere in this repository, and there is no "local dependency missing → fall back to cloud" path. PNG/SVG/PDF export happens only in the assistant plugins, which shell out to your **locally installed draw.io Desktop CLI** (located via `which drawio`); if it isn't installed, the `.drawio` file is kept and nothing is sent. ### Does your diagram leave the machine? | Approach | Diagram leaves the machine? | |---|---| | **MCP App Server — hosted (`mcp.draw.io`)** | **Yes** — it is sent to the draw.io server as the MCP request. Self-host instead (below) to keep it local. | | **MCP App Server — self-hosted** (local Node or your own Cloudflare) | No — processed by your server and embedded in HTML that renders client-side. | | **MCP Tool Server** (`@drawio/mcp`) | No — carried in the URL `#fragment`, which browsers do not transmit to the server. | | **Assistant Plugins** (Claude Code, Codex CLI) | No — written locally and exported by your local draw.io Desktop CLI. | By default the servers do not write diagram content to their logs — only request metadata (method, session, status, timing). The Cloudflare-hosted App Server logs response bodies only when run with `DEBUG=true`. ### Reducing external requests Even when the diagram itself stays local, the rendering loads draw.io's web-app / viewer **code** from `app.diagrams.net` and `viewer.diagrams.net` by default. These fetch application code and assets — not your diagram — but they are still outbound requests. To reduce or remove them: - **App Server:** build with the `VIEWER_PATH` environment variable to inline the viewer instead of loading it from `viewer.diagrams.net`. - **Tool Server:** set the `DRAWIO_BASE_URL` environment variable to a self-hosted draw.io instance. - **Assistant Plugins:** the opt-in `/drawio:drawio url` mode opens the diagram at `app.diagrams.net` (hardcoded — no `DRAWIO_BASE_URL` equivalent). Use the default `.drawio` output or local Desktop export instead if you need to avoid that request. ### Your LLM is a separate consideration The diagram is *generated* by the LLM. If you use a hosted model, the diagram content is produced in that provider's cloud regardless of where this MCP server runs. End-to-end isolation requires a locally hosted model as well. ### Verifying The only reliable way to confirm a deployment makes **no** outbound calls is to run it with network egress blocked (or watch the browser's Network tab) and verify it still renders. We recommend this for any strict-isolation deployment. --- ## XML Reference (Single Source of Truth) The draw.io XML generation reference — covering edge routing, containers, layers, tags, metadata, dark mode, style properties, and XML well-formedness — lives in a single canonical file: **[`shared/xml-reference.md`](https://github.com/jgraph/drawio-mcp/blob/HEAD/shared/xml-reference.md)** All four approaches above use this file as their single source of truth for LLM prompts: | Approach | How it accesses the reference | |----------|-------------------------------| | MCP App Server | Reads the file at startup / build time and includes it in the tool description | | MCP Tool Server | Reads the file at startup (from repo or bundled copy via `prepack`) | | Assistant Plugins (Claude Code, Codex CLI) | Reference the [GitHub raw URL](https://raw.githubusercontent.com/jgraph/drawio-mcp/main/shared/xml-reference.md) | | Project Instructions | Users copy its contents into their Claude Project | When updating XML generation guidance, edit only `shared/xml-reference.md` — changes propagate to all consumers automatically. --- ## Shape Search Index The `search_shapes` tool is powered by a pre-built index of all draw.io shapes. The index is generated from the live draw.io client (`https://app.diagrams.net/js/app.min.js`) by running all sidebar palette initializations in Node.js via jsdom and capturing the shape data. Icons from the draw.io icon service (`icons.diagrams.net` — the same grouped icon search the editor sidebar uses) are **not** part of this index: `search_shapes` queries the service live when the local index has no strong match for a query, returning the icons as `shape=image` styles. Set `DRAWIO_ICON_SERVICE_URL` to a self-hosted service to override the endpoint, or to `off` to disable icon supplementation. `shape-search/search-index.json` is committed to the repository and is **automatically refreshed on every draw.io release** via the [Update Shape Search Index](https://github.com/jgraph/drawio-mcp/blob/HEAD/.github/workflows/update-search-index.yml) GitHub Action — no manual step is required to stay in sync with the latest shapes. To regenerate the index manually (e.g. when iterating on the generator itself): ```bash cd shape-search npm install npm run generate # Rebuild the MCP App Server worker to embed the updated index cd ../mcp-app-server npm run build:worker ``` The generator fetches `app.min.js` directly from the public draw.io web app, so no local checkout of the draw.io source is needed. --- ## Development ```bash # MCP App Server cd mcp-app-server npm install npm start # MCP Tool Server cd mcp-tool-server npm install npm start ``` ## Related Resources - [draw.io](https://www.draw.io) - Free online diagram editor - [draw.io Desktop](https://github.com/jgraph/drawio-desktop) - Desktop application - [@drawio/mcp on npm](https://www.npmjs.com/package/@drawio/mcp) - This package on npm - [drawio-mcp on GitHub](https://github.com/jgraph/drawio-mcp) - Source code repository - [Mermaid.js Documentation](https://mermaid.js.org/intro/) - [MCP Specification](https://modelcontextprotocol.io/) - [MCP Apps Extension](https://modelcontextprotocol.io/docs/extensions/apps)