excalidraw-mcp — Claude Code MCP server: edit Excalidraw diagrams
An MCP server that lets your agent add nodes and arrows to an Excalidraw file and read the whole diagram back. Handy when a schema has to change from inside the chat.
claude mcp add excalidraw-mcp -- npx -y @cmd8/excalidraw-mcpWhat excalidraw-mcp does
Four tools come with the server. createNode drops in a shape with a label and hands back its ID. createEdge draws an arrow between two nodes, and you can point at either an ID or the label text. deleteElement removes a node or an edge, while getFullDiagramState returns a markdown view of the diagram: nodes, relationships, labels, frames and colors.
It runs through npx, so Node.js 18.0.0 or newer has to be on the machine. The -d, --diagram flag is required at startup and takes the path to a .excalidraw file; skip it and the server never comes up. You set that path once in the config, and the agent keeps working against that one file.
Wiring it in is either a single terminal command or a JSON block in your editor's MCP settings. Claude takes claude mcp add, Codex takes codex mcp add, Gemini CLI takes gemini mcp add. Cursor, Windsurf, GitHub Copilot and VS Code expect the server in a config file you edit yourself.
What it helps with
- sketch a service diagram out of nodes and arrows
- add a labeled box to a diagram that already exists
- connect two nodes by label text when the IDs are unknown
- read the current diagram state as markdown
- drop a node or edge you no longer need
Example prompts for the agent
- Add a node called "Queue" to the diagram and connect it to "API"
- Show me the full diagram state in markdown
- Delete the edge between "Client" and "Gateway"
How to install excalidraw-mcp
Platform CLI
claude mcp add excalidraw-mcp -- npx -y @cmd8/excalidraw-mcpPlatform CLI
codex mcp add excalidraw-mcp -- npx -y @cmd8/excalidraw-mcpConfig file
{
"mcpServers": {
"excalidraw-mcp": {
"command": "npx",
"args": [
"-y",
"@cmd8/excalidraw-mcp"
]
}
}
}Config file
{
"servers": {
"excalidraw-mcp": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"@cmd8/excalidraw-mcp"
]
}
}
}Platform CLI
gemini mcp add excalidraw-mcp npx -y @cmd8/excalidraw-mcpStep by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about excalidraw-mcp
How do I install excalidraw-mcp in Claude Code?
Run claude mcp add excalidraw-mcp -- npx -y @cmd8/excalidraw-mcp. Add the diagram path with the --diagram flag.
What does excalidraw-mcp do?
It lets an agent create nodes and arrows in an Excalidraw file, delete elements, and pull a markdown description of the entire diagram.
What do I need before running it?
Node.js 18.0.0 or newer, plus the path to a .excalidraw file passed through the required -d, --diagram flag.
