UML-MCP

UML-MCP

UML-MCP gives an AI assistant a real diagram tool instead of asking it to fake diagrams in Markdown. Connect it once over MCP, then ask for a class diagram, sequence diagram, architecture view, Mermaid flowchart, D2 graph, BPMN process, or another Kroki-backed format. The server validates the source, renders it, and returns a URL, playground link, or inline image.

It also works as a building block for agent-facing products. Use MCP when an agent needs diagram tools, AG-UI when a frontend needs a standard event stream, and OpenUI when the product should turn model output into interactive, application-owned UI components. These layers complement each other; UML-MCP stays focused on diagram generation.

_{Chat reply shape: diagram preview · URL · Playground (mermaid.live)}

Quick start

Remote (recommended) — add to your MCP client:

"uml-mcp": {
  "transport": "http",
  "url": "https://uml-mcp.vercel.app/mcp"
}

Use /mcp, not the site root. Then ask: “Draw a sequence diagram of a user logging in through an API gateway.” or paste PlantUML / Mermaid / Kroki source.

Repo defaults: .cursor/mcp.json · .vscode/mcp.json · .codex/config.toml.

All snippets: config/README.md

Install locally (guided):

Guide: docs/installation.md

_{Admin console (uml-mcp admin): overview · setup · settings · activity · logs · metrics · plugins, light and dark, desktop and mobile}

git clone https://github.com/antoinebou12/uml-mcp.git
cd uml-mcp
uv sync
uv run python server.py

git remote add origin https://github.com/antoinebou12/uml-mcp.git

/plugin marketplace add https://github.com/antoinebou12/uml-mcp
/plugin install uml-mcp@uml-mcp-plugins

At a glance

docker compose up -d
docker build -t uml-mcp . && docker run -p 8000:8000 uml-mcp
docker run -i uml-mcp python server.py --transport stdio

server.py / app.py     -- MCP + FastAPI (/mcp)
mcp_core/tools/        -- generate_uml, generate_uml_image, validate, batch
tools/kroki/           -- Kroki, PlantUML, Mermaid, D2

uv sync --all-groups
uv run pytest tests/ -v
uv run ruff check . && uv run ruff format --check .
make ci

Community

If this survives a real production repo, it beats a lot of polished launch demos.

— @AIDailyGems on antoinebou12/uml-mcp

Daily and monthly activity (stars, forks, merged PRs, issues): trendshift.io/repositories/42725

Links

Maintained by Antoine Boucher. Built on PlantUML, Kroki, Mermaid, and D2.