Usage

•/diagram sequence user login flow - Create a sequence diagram
•/diagram component for README.md - Create a component diagram and add to README
•/diagram class data models - Create a class diagram

Steps

•
Determine diagram type from arguments:
- •sequence - Interactions between actors/systems
- •component - System architecture and dependencies
- •class - Data models and relationships
- •activity - Workflows and decision flows
- •state - State machines
•
Create the PlantUML syntax appropriate for the type

•

Generate URLs using the plantuml plugin MCP server:

bash

cd /path/to/plugins/plantuml && printf '%s\n%s\n%s\n' \
  '{"jsonrpc":"2.0","id":0,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"claude","version":"1.0"}}}' \
  '{"jsonrpc":"2.0","method":"notifications/initialized"}' \
  '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"plantuml_generate_urls","arguments":{"diagram":"..."}}}' \
  | python3 main.py

•
If a target file is specified, add the diagram to it:
- •Insert image as a clickable link to the editor: [![description](png-url)](editor-url)
- •The PNG renders inline in documentation; clicking it opens the PlantUML editor
- •Add collapsible source in a <details> block
•
Show the user:
- •The generated URLs (png, svg, editor)
- •The PlantUML source code

Diagram Templates

Sequence

plantuml

@startuml
actor User
participant "System A" as A
participant "System B" as B

User -> A: request
A -> B: process
B --> A: response
A --> User: result
@enduml

Component

plantuml

@startuml
package "System" {
  [Component A] as A
  [Component B] as B
}
A --> B : uses
@enduml

Class

plantuml

@startuml
class Entity {
  +id: string
  +name: string
  +save(): void
}
@enduml

Output Format

When adding to a file, wrap the image in a link to the editor so it renders inline and opens the editor on click:

markdown

[![Diagram description](https://www.plantuml.com/plantuml/png/~1...)](https://www.plantuml.com/plantuml/uml/~1...)

<details>
<summary>PlantUML source</summary>

\`\`\`plantuml
@startuml
...
@enduml
\`\`\`

</details>