PlantUML MCP Server
A Model Context Protocol (MCP) server that wraps PlantUML functionality, allowing AI assistants to generate UML diagrams from text descriptions.
Features
- Generate Diagrams: Create diagrams in multiple formats (PNG, SVG, TXT, PDF, etc.)
- Syntax Checking: Validate PlantUML syntax without generating images
- Source Extraction: Extract PlantUML source from PNG/SVG metadata
- Dark Mode Support: Generate diagrams with dark theme
- Version Info: Get PlantUML and Java version information
Prerequisites
- Node.js 18 or higher
- Java Runtime Environment (JRE)
- PlantUML JAR file
Installation
- Clone this repository:
git clone <repository-url>
cd planuml
- Install dependencies:
npm install
- Build the project:
npm run build
- Set the PlantUML JAR path (optional):
export PLANTUML_JAR=/path/to/plantuml.jar
Default path: /Users/userxxx/bin/plantuml.jar
Usage
As an MCP Server
Add to your MCP client configuration (e.g., Claude Desktop):
{
"mcpServers": {
"plantuml": {
"command": "node",
"args": ["xxx/dist/index.js"],
"env": {
"PLANTUML_JAR": "xxx/plantuml.jar"
}
}
}
}
Available Tools
1. generate_diagram
Generate a diagram from PlantUML source code.
Parameters:
source(required): PlantUML source codeformat(optional): Output format -png,svg,txt,utxt,eps,latex,pdf(default:png)darkMode(optional): Render in dark mode (default:false)
Returns: Base64-encoded diagram data
Example:
{
"source": "@startuml\nAlice -> Bob: Hello\n@enduml",
"format": "svg",
"darkMode": false
}
2. check_syntax
Check PlantUML diagram syntax without generating images.
Parameters:
source(required): PlantUML source code to validate
Returns: Validation result or syntax errors
Example:
{
"source": "@startuml\nAlice -> Bob: Hello\n@enduml"
}
3. extract_source
Extract embedded PlantUML source from PNG or SVG metadata.
Parameters:
filePath(required): Path to the PNG or SVG file
Returns: Extracted PlantUML source code
Example:
{
"filePath": "/path/to/diagram.png"
}
4. get_plantuml_version
Get PlantUML and Java version information.
Parameters: None
Returns: Version information
PlantUML Syntax Examples
Sequence Diagram
@startuml
Alice -> Bob: Authentication Request
Bob --> Alice: Authentication Response
@enduml
Class Diagram
@startuml
class User {
+String name
+String email
+login()
+logout()
}
class Admin {
+manageUsers()
}
User <|-- Admin
@enduml
Activity Diagram
@startuml
start
:Initialize;
if (Check condition?) then (yes)
:Process A;
else (no)
:Process B;
endif
stop
@enduml
Use Case Diagram
@startuml
left to right direction
actor User
actor Admin
rectangle System {
User -- (Login)
User -- (View Profile)
Admin -- (Manage Users)
Admin -- (View Reports)
}
@enduml
Development
Build
npm run build
Watch mode
npm run watch
Environment Variables
PLANTUML_JAR: Path to the PlantUML JAR file (default:/Users/userxxx/bin/plantuml.jar)
Supported Output Formats
- png: PNG images (default)
- svg: SVG vector graphics
- txt: ASCII art diagrams
- utxt: ASCII art with Unicode characters
- eps: Encapsulated PostScript
- latex: LaTeX/TikZ output
- pdf: PDF documents
Error Handling
The server handles various error scenarios:
- Invalid PlantUML syntax
- Missing PlantUML JAR file
- Java runtime errors
- File I/O errors
Errors are returned with descriptive messages to help diagnose issues.
License
MIT