draw.io MCP in Claude and Claude Code: setup, tools and limits

We read the hosted server's source on 22 October 2026, at version 1.4.1. It gives Claude three tools:

• create_diagram takes draw.io XML or Mermaid code, one or the other, and shows it as an interactive diagram. Its description tells Claude to use XML for diagrams of boxes and lines up to about 30 shapes, and Mermaid for sequence diagrams, Gantt charts, the other Mermaid-only types and bigger flowcharts. Two optional passes tidy the layout: postLayout: "elk" rearranges the shapes, and routing: "libavoid", for XML only, leaves them where Claude put them and reroutes the connectors around them.
• search_shapes searches about 10,000 shapes in draw.io's libraries, among them AWS, Azure, Google Cloud, Cisco, Kubernetes, P&ID and electrical, and returns the exact style string to put in the XML. When the libraries have no good match, it also asks draw.io's icon service for brand logos and general icons. Its description tells Claude to skip it for flowcharts, UML, ER diagrams, org charts and mind maps.
• get_drawio_reference returns draw.io's guide to writing XML or Mermaid. Claude is told to call it once per format before its first diagram in a conversation. The server's README says this text used to sit in create_diagram's description, which made that description about 55,000 characters long.

None of the three opens or saves a file. To change a diagram, you ask in the same chat. draw.io's page on changes says the viewer passes the diagram back to Claude as it is shown, and Claude "changes what you asked for, keeps everything else (positions, text, colours)" and shows the new version below the old one. By draw.io's timing, a change takes 25 to 45 seconds.

The viewer has zoom, Fit, Fullscreen, Expand for tall diagrams, and a Layout button that switches a Mermaid flowchart to an automatic layered layout. Open in draw.io opens the diagram in the full editor, where you can edit, save or export it. Copy puts the draw.io XML on your clipboard, and Download saves a .drawio file "in apps that allow downloads". In Claude, the shapes appear one by one as Claude writes them.

Claude Code needs a Pro, Max, Team, Enterprise or Console account; Anthropic's setup page says the free claude.ai plan doesn't include it. draw.io documents three ways in.

The plugin, for files. This is the route draw.io's docs page gives for Claude Code. Inside Claude Code, add the marketplace and install it:

/plugin marketplace add jgraph/drawio-mcp
/plugin install drawio@drawio

Then ask for a diagram. By default the plugin's skill writes a .drawio file and opens it. Add png, svg or pdf to your request to export it, with the diagram embedded so the file still opens for editing in draw.io, or url to open it at app.diagrams.net and keep the .drawio file. Exports and Mermaid conversion need draw.io Desktop. Without it, the skill writes draw.io XML. To call it by name, type /drawio:drawio followed by your request.

draw.io's docs page says the plugins need "No MCP setup", which is true of the install. The plugin's README adds that since version 1.2.3 it also brings the hosted server into Claude Code, that in the terminal the skill keeps writing files, and that diagrams drawn with the hosted server are sent to mcp.draw.io. To keep everything on your machine, turn the plugin's drawio server off in /mcp.

The hosted server, for a link. Add it over HTTP, then run /mcp to check that it connected:

claude mcp add --transport http drawio https://mcp.draw.io/mcp

Neither of draw.io's own pages gives this command: the docs page lists the plugin for Claude Code, and the setup page lists the plugin's options and the tool server. The MCP App Server README covers this route: "In other hosts, such as Claude Code, the server answers with a link that opens the diagram in draw.io." If Claude Code is signed in with your claude.ai account and you already connected draw.io there, the connector shows up in /mcp by itself. Anthropic's MCP docs say a server you add in Claude Code takes precedence over a claude.ai connector with the same URL, and /mcp then lists the connector as hidden.

The tool server, for the full editor. draw.io's setup page gives this command for opening diagrams in the editor. It needs Node.js:

claude mcp add drawio -- npx -y @drawio/mcp

Each diagram opens in a new draw.io editor tab in your browser, from XML, CSV or Mermaid. It is the only official option that works on files you already have: list_pages, get_page and set_page read and replace one page of a local .drawio file and leave the others alone. The diagram travels in the part of the link after the #, which browsers don't send to the server. If you also added the hosted server as drawio, give this one another name.

drawio-mcp-server, by Ladislav Gazo, is a separate project. It runs on your computer and drives a live draw.io editor: a built-in one at http://localhost:3000, or draw.io in your browser through its Chrome or Firefox extension. Its 30 tools add, edit and delete single shapes and edges, manage pages and layers, import Mermaid, and export XML, SVG or PNG with the diagram embedded.

On 22 October 2026 we ran the hosted server in Claude Code 2.1.114, in a terminal on a Mac. We added https://mcp.draw.io/mcp in an MCP config file in the project and started Claude Code with --strict-mcp-config, so it loaded no other MCP server. There was nothing to sign in to and nothing to install. We turned off Claude Code's own tools (Bash, Write, Edit, Read, Glob, Grep, WebFetch, WebSearch and Task), so draw.io was the only thing that could act. The prompt is the one from our Excalidraw and tldraw tests, word for word, including the last sentence, which asks for something draw.io doesn't do:

Draw a diagram of how a RAG pipeline answers a question: user question, embed the question, vector search, top-k chunks, prompt with context, LLM answer. Then export it to excalidraw.com and give me the link.

The server offered its three tools: create_diagram, get_drawio_reference and search_shapes. Claude first used Claude Code's tool search to load them, then called two of them:

1. get_drawio_reference with the format set to XML. It returned draw.io's XML guide, 47,312 characters long.
2. create_diagram with Claude's XML. The answer was 5,785 characters: the diagram's XML and an app.diagrams.net link. The whole diagram is compressed into the part of the link after the #, which was 1,191 characters.

It didn't call search_shapes, which the tool's description says to skip for flowcharts.

The input numbers include Claude Code's own system prompt. Our Excalidraw and tldraw runs sent the same prompt through the Claude API instead, so compare their drawings with this one but not their token counts.

The terminal showed only the link, since a terminal can't show draw.io's viewer. Claude then said it couldn't export to excalidraw.com and offered an SVG export or a Mermaid version instead. Opening the link showed the diagram in the draw.io editor:

What the run tells you:

• In Claude Code you get a link, as draw.io says. Open it to see and edit the diagram, and save it from the editor. For .drawio files in your project, use draw.io's plugin.
• The link holds the diagram. Anyone you send it to can open the whole diagram, so share it the way you would share the file.
• Turn off the tools you don't want used. In our first try we had left Claude Code's shell on. After drawing with draw.io, Claude wrote its own script and put the diagram on a public excalidraw.com share link, to answer the prompt's last sentence. If you want only draw.io to act, turn the other tools off, for example with --disallowedTools on claude -p, or approve each tool call yourself.
• We didn't test the viewer inside the Claude app. This run was in a terminal, so the in-chat viewer and its buttons aren't part of it.

draw.io's server is the one to pick for technical diagrams that need a shape library, such as cloud architecture or network diagrams. For a quick hand-drawn sketch with a link to share, see our Excalidraw MCP guide; for a canvas Claude edits shape by shape inside the chat, the tldraw MCP guide; and for diagrams that have to land on your team's boards, the Miro MCP guide. Our Excalidraw vs tldraw vs Miro comparison puts those three side by side, and the list of whiteboard and diagram MCP servers has the address, sign-in and cost for the rest.

It doesn't, for diagrams. We make Creatos, a desktop canvas where one source, such as a PDF or a YouTube video, connects to several AI models so you can read their answers side by side. It has no MCP server today, so Claude can't draw on it. It uses your own API keys or local models through Ollama and runs on macOS and Windows. A new download gets a 7-day free trial. After that, the lifetime license is $69 once until 18 November 2026, then $99.