Next AI Draw.io MCP Server

An MCP server that lets Claude Code, Cursor, VS Code and other AI agents draw draw.io diagrams from your project's files, with a live preview in your browser. The preview is the canvas of the Next AI Draw.io web app: the AI's changes are outlined, Ctrl+Z takes them back, and you can edit by hand at any time.

https://github.com/user-attachments/assets/6f53a67b-ab21-4113-9fee-7fb32f9de678

Install

In VS Code or Cursor, one click adds it:

Let your AI agent install it

Paste this into Claude Code, Codex, Cursor, VS Code, Cline or any agent that can edit files and run commands:

Install the drawio MCP server for the client you are running in, following
https://raw.githubusercontent.com/DayuanJiang/next-ai-draw-io/main/packages/mcp-server/README.md
Install it for all my projects (user scope, for Claude Code "--scope user"),
name the server "drawio" and keep the servers that are already configured.
Then tell me how to reload so its tools show up.

Install by hand

Claude Code

claude mcp add --scope user drawio -- npx @next-ai-drawio/mcp-server@latest

--scope user makes the tools available in every project. Without it, they exist only in the folder where you ran the command.

Or install it as a plugin from the Claude Code community marketplace (Claude Code 2.1.275 or later):

/plugin install next-ai-drawio --marketplace anthropics/claude-plugins-community

Codex CLI

codex mcp add drawio -- npx @next-ai-drawio/mcp-server@latest

Codex asks before each drawio tool that changes the diagram, and codex exec without full access fails with "MCP tool call requires approval". To let the drawio tools run without asking, add one line to the server's section in ~/.codex/config.toml:

[mcp_servers.drawio]
command = "npx"
args = ["@next-ai-drawio/mcp-server@latest"]
default_tools_approval_mode = "approve"

To approve only some tools, use [mcp_servers.drawio.tools.<tool name>] with approval_mode = "approve" instead.

VS Code (.vscode/mcp.json)

{
  "servers": {
    "drawio": { "type": "stdio", "command": "npx", "args": ["@next-ai-drawio/mcp-server@latest"] }
  }
}

Cursor, Claude Desktop, Cline and most other clients (~/.cursor/mcp.json, claude_desktop_config.json, cline_mcp_settings.json)

{
  "mcpServers": {
    "drawio": { "command": "npx", "args": ["@next-ai-drawio/mcp-server@latest"] }
  }
}

Restart the client, then ask, for example, "Read this repo and draw its architecture". The preview opens in your browser and the diagram appears as it is drawn.

Features

• Draws from your project: the agent reads your code and documents with its own tools. Existing .drawio and .drawio.svg files open with load_diagram.
• The web app's canvas: the AI's changes are outlined for a few seconds (never in exports) and one Ctrl+Z takes them back. Select shapes and say "these" (get_selection). Your hand edits are read before the AI edits again.
• Real icons: the web app's drawing rules and shape libraries (AWS, Azure, GCP, Kubernetes, Cisco and more), so the AI uses real icon names.
• Self-check: the AI can look at a screenshot of the rendered diagram and fix overlaps (screenshot: true, or screenshot_diagram).
• Versions: the last 20 versions as cards next to the canvas; restore or compare one, or ask the AI to undo (restore_version).
• Pages and export: multi-page diagrams; save as .drawio, .png, .svg or .drawio.svg. Images get a 20 px margin, and PNGs a white background (transparent: true for none).
• Offline: the draw.io editor ships inside the package.

Choosing a draw.io MCP server

Several MCP servers draw draw.io diagrams. As of October 2026 they differ like this:

| Server | How you see and change the diagram | A good fit when | |---|---|---| | This server, @next-ai-drawio/mcp-server | A live draw.io canvas in your browser. The AI reads it back, including your hand edits and selection; its changes are outlined, Ctrl+Z takes them back, and earlier versions can be restored | You and the AI take turns on the same diagram | | draw.io's official @drawio/mcp | Opens each diagram from XML, CSV or Mermaid in the draw.io editor in a new tab; no tool reads it back | You want the diagram in the full draw.io editor and edit it yourself from there | | draw.io's hosted MCP app, https://mcp.draw.io/mcp | Shows the diagram inside the chat in Claude.ai, ChatGPT, VS Code or Cursor, with nothing to install; the diagram is sent to draw.io's server | You work in a chat app and want to see the diagram in the conversation | | draw.io's plugin for Claude Code, Codex CLI and Copilot CLI | A skill that writes .drawio files; PNG, SVG and PDF export needs draw.io Desktop | You want diagram files in your repository without an MCP server | | lgazo/drawio-mcp-server | A draw.io editor on localhost, or your own draw.io through a browser extension; tools create, read, update and delete single shapes, layers and pages | You want fine-grained tools, several documents at once, or Mermaid import |

Saved diagrams

Every change is saved to ~/.next-ai-drawio/<session-id>.drawio with its last 20 versions; the newest 50 diagrams are kept. To continue one in a later conversation, ask the AI for it: it finds it with list_saved_diagrams and reopens it with start_session.

Your own drawing rules

Write them in ~/.next-ai-drawio/instructions.md, for example "Always use a minimal style". They are added to the drawing guide on every call, so edits apply without a restart. The first 5000 characters are used.

Tools

| Tool | What it does | |---|---| | start_session | Open the preview and return the drawing guide; session_id continues a saved diagram | | create_new_diagram | Draw a new diagram from mxCell XML | | edit_diagram | Add, update or delete cells by id, all or nothing | | get_diagram | The current XML, including your edits in the browser | | get_selection | The shapes you selected in the preview | | screenshot_diagram | A PNG of a page, for the AI to check | | load_diagram, export_diagram | Open a .drawio or .drawio.svg file; save .drawio, .png, .svg or .drawio.svg | | restore_version | Go back to an earlier version; a redo stays possible | | list_saved_diagrams | Diagrams saved by earlier sessions, newest first | | get_drawing_guide, get_shape_library | The drawing rules again; the icon styles of a library such as aws4 | | list_pages, add_page, rename_page, delete_page | Pages (tabs) |

Configuration

Environment variables, set in the client's env for the server:

| Variable | Default | What it does | |---|---|---| | PORT | 6002 | Preview port; when it is taken, the next free one up to 6020 is used | | DRAWIO_DATA_DIR | ~/.next-ai-drawio | Folder for saved diagrams and instructions.md; off turns saving off | | DRAWIO_AUTO_SCREENSHOT | unset | true attaches a screenshot to every create and edit result (2 to 10 s per call) | | DRAWIO_BASE_URL | the bundled draw.io | Use another draw.io, such as a self-hosted one (see below) | | DRAWIO_LANG | unset | Fix the editor and preview language: en, zh, zh-tw, ja, de and so on | | DRAWIO_UI | unset | Fix the draw.io theme: kennedy, atlas, dark, min, sketch or simple | | DRAWIO_DARK | auto | 1 starts dark, 0 starts light, auto follows the system | | BROWSER | unset | none does not open the preview by itself; start_session still returns the URL | | DRAWIO_PREVIEW_UI | shell | classic opens the previous preview page, without outlines, Ctrl+Z or get_selection | | DEBUG | unset | true logs debug messages to stderr |

Self-hosted draw.io

docker run -d -p 8080:8080 jgraph/drawio

Then set DRAWIO_BASE_URL=http://localhost:8080. The preview cannot reach into a draw.io from another origin, so the AI's changes are not outlined, Ctrl+Z does not take them back (use the version cards) and get_selection does not work. The bundled copy leaves out a few features that load code on demand, such as the org chart layout. It also has no image proxy, so exported images leave out pictures inserted by their web address; see Offline deployment.

Troubleshooting

• Blank preview in VS Code Simple Browser or Cursor's browser: the page refuses to be embedded in other pages. Open the URL in a regular browser.
• Screenshot or PNG/SVG export times out: the preview tab renders them, and browsers slow down background tabs. Bring the tab to the front and try again.
• "No active session": the AI has to call start_session first.
• The preview does not update: open the URL that start_session returned; its ?mcp= part connects the page to the session.

How it works

The server talks to the agent over stdio and runs an HTTP server on 127.0.0.1 that serves the preview page and the bundled draw.io; the page polls it for changes. Every /api request needs a token that only the preview page has, so other websites cannot read or change your diagram.

License

Apache-2.0