Umlout MCP Server
Let your AI assistant draw on a real whiteboard.
Umlout exposes a hosted Model Context Protocol server, so Claude, Cursor, VS Code Copilot and any other MCP client can create and edit diagrams in your Umlout workspace — UML class and sequence diagrams, flowcharts, activity diagrams, wireframes and domain models.
Nothing to install and nothing to run: the server is hosted at https://www.umlout.com/mcp/sse.
You only need an API key.
Quick start
1. Get an API key. Sign in at umlout.com, open Profile → MCP API Keys, and create a key.
2. Add the server to your client.
Claude Code
claude mcp add --transport sse umlout https://www.umlout.com/mcp/sse --header "Authorization: Bearer YOUR_API_KEY"
More options, including project scope: examples/claude-code.md.
Cursor · VS Code — clients that speak remote SSE natively
~/.cursor/mcp.json:
{
"mcpServers": {
"umlout": {
"url": "https://www.umlout.com/mcp/sse",
"headers": { "Authorization": "Bearer YOUR_API_KEY" }
}
}
}
For VS Code Copilot use examples/vscode.json — it prompts for the key and keeps it in VS Code's secret storage instead of a committed file.
Claude Desktop — via the mcp-remote bridge
Claude Desktop's config file does not take a remote URL directly, so route it through
mcp-remote (needs Node.js). Edit
~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or
%APPDATA%\Claude\claude_desktop_config.json (Windows):
{
"mcpServers": {
"umlout": {
"command": "npx",
"args": [
"-y", "mcp-remote", "https://www.umlout.com/mcp/sse",
"--header", "Authorization: Bearer YOUR_API_KEY"
]
}
}
}
Then quit Claude Desktop completely and reopen it — closing the window is not enough.
3. Ask for a diagram:
Draw a UML sequence diagram of an OAuth2 authorization code flow on a new board called "Auth".
Verify your setup at any time:
python3 scripts/check_connection.py --api-key YOUR_API_KEY
What it can do
37 tools across four areas, plus 4 read-only resources. Full reference with every argument: docs/tools.md and docs/resources.md.
| Area | What the assistant can do |
|---|---|
| Diagrams | Create, list, find, rename, clear and delete boards |
| Shapes & connections | Add and edit shapes, draw connections with UML notation, place sequence messages, define custom anchor points, bulk-create hundreds of elements in one call |
| Domain models | Build nestable folders → elements → relations; create a whole model tree in a single call |
| Comments | Add, list, resolve and delete comments and replies on any element |
The shape vocabulary covers 70 types — basic geometry, UML class/interface/package, sequence (actor, lifeline, activation, fragment), activity (action, decision, fork/join, swimlanes), and a full wireframe kit (screens, buttons, inputs, navbars, tables, cards).
Things worth asking for
- "Turn this OpenAPI spec into a component diagram."
- "Sketch the mobile onboarding flow as wireframes — three screens."
- "Read the board 'Checkout' and tell me which states have no outgoing transitions."
- "Build a domain model from these requirements: orders, invoices, customers."
Authentication and limits
Every request carries your key in Authorization: Bearer <key> (or X-API-Key). Keys are scoped
to your account — the assistant sees exactly the diagrams you can see, and nothing else.
| Limit | Value |
|---|---|
| Requests | 60 per minute |
| Write tool calls | 600 per hour |
Bulk write calls (bulk_*) | 60 per hour |
Details, key rotation and revocation: docs/authentication.md. Something not working? docs/troubleshooting.md.
About this repository
This repo is the public home of the Umlout MCP connector: documentation, client configs, the registry manifest (server.json) and a connection checker. The server itself is a hosted service — there is no local installation, so there is no server source here.
Issues and questions about the MCP integration are welcome in Issues.
License
MIT — documentation and examples.