PlantUML MCP Server

@mzagar

Basic information

About PlantUML MCP Server

A Model Context Protocol (MCP) server that provides PlantUML diagram generation capabilities for Claude Desktop and Claude Code.

#plantuml#puml#uml #diagram #diagrams

PlantUML MCP Server config

Add this server to your MCP-compatible client using the configuration below.

{
  "mcpServers": {
    "plantuml": {
      "command": "npx",
      "args": [
        "plantuml-mcp-server"
      ],
      "env": {
        "PLANTUML_SERVER_URL": "https://www.plantuml.com/plantuml"
      }
    }
  }
}

PlantUML MCP Server tools

Generate a PlantUML diagram with automatic syntax validation and error reporting for auto-fix workflows. Returns embeddable image URLs for valid diagrams or structured error details for invalid syntax that can be automatically corrected. Optionally saves the diagram to a local file.

Encode PlantUML code for URL usage

Decode encoded PlantUML string back to PlantUML code

Overview

What is PlantUML-MCP-Server?

A Model Context Protocol (MCP) server that integrates PlantUML diagram generation into Claude Desktop and Claude Code. It provides tools to generate, encode, and decode PlantUML diagrams, producing embeddable SVG/PNG URLs.

How to use PlantUML-MCP-Server?

Add the server to Claude Desktop or Claude Code using npx plantuml-mcp-server and optionally set the PLANTUML_SERVER_URL environment variable (defaults to public PlantUML server). After activation, ask Claude to generate any PlantUML diagram type (sequence, class, C4, etc.) using the generate_plantuml_diagram tool.

Key features of PlantUML-MCP-Server

Three tools: generate, encode, and decode PlantUML diagrams.
Produces embeddable SVG/PNG URLs for diagrams.
Supports advanced PlantUML features like !include and external libraries.
Configurable PlantUML server URL via environment variable.
Works with both Claude Desktop and Claude Code.

Use cases of PlantUML-MCP-Server

Quickly create sequence diagrams to document workflows within Claude.
Generate C4 architecture diagrams for software projects.
Encode or decode PlantUML code for sharing via URLs.
Embed diagrams in Claude responses without leaving the chat.

Frequently asked questions

What tools does PlantUML-MCP-Server provide?

It provides three tools: `generate_plantuml_diagram` to create diagrams with SVG/PNG URLs, `encode_plantuml` to convert PlantUML code into an encoded string, and `decode_plantuml` to reverse the encoding.

How do I configure a custom PlantUML server?

Set the `PLANTUML_SERVER_URL` environment variable to your server’s URL when adding the MCP server to Claude Desktop or Claude Code (default is `https://www.plantuml.com/plantuml`).

What are the runtime requirements?

Node.js 18+ and npm are required for local installation. The server runs via `npx` without local installation for normal use.

Does this server store any data or require authentication?

No. The server only interacts with the configured PlantUML server to generate/encode/decode diagrams; no authentication or persistent storage is mentioned.

What transport protocol does the server use?

It uses the standard Model Context Protocol (MCP) for communication with Claude clients; no custom transports are specified.

Comments

More Other MCP servers

MCP Toolbox for Databases

googleapis

MCP Toolbox for Databases is an open source MCP server for databases.

15.9K

Volley.sh

Volley

A good sequence diagram can solve almost any communication problem in engineering. Volley lets your agent write them as plain text, with the real request and response payloads on every arrow. It checks its own syntax wi

Blender

ahujasid

Open-source MCP to use Blender with any LLM

23.6K

Hindsight

vectorize-io

Hindsight: Agent Memory That Learns

50.4K

Screenpipe

screenpipe

YC (S26) | Open Computer History | Continuously record your company computer work, map your workflows, help you find work worth automating, and power your agents' context

22.0K