| name | plantuml |
| description | Generate PlantUML diagrams from text descriptions and convert them to PNG/SVG images. Use when asked to "create a diagram", "generate PlantUML", "convert puml to image", "extract diagrams from markdown", or "prepare markdown for Confluence". Supports all PlantUML diagram types including UML (sequence, class, activity, state, component, deployment, use case, object, timing) and non-UML (ER diagrams, Gantt charts, JSON/YAML visualization, mindmaps, WBS, network diagrams, wireframes, and more). |
PlantUML Diagram Generation and Conversion
Table of Contents
Purpose
This skill enables comprehensive PlantUML diagram creation and conversion workflows. PlantUML is a text-based diagramming tool that generates professional diagrams from simple, intuitive syntax.
Core capabilities:
- Create diagrams from natural language descriptions
- Convert source code to architecture diagrams (Spring Boot, FastAPI, Python ETL, Node.js, React)
- Convert standalone
.puml files to PNG or SVG images
- Extract
puml code blocks from markdown and convert to images
- Process linked
.puml files in markdown ()
- Validate PlantUML syntax without conversion
- Replace markdown diagrams with image links for publication (Confluence, Notion)
When to Use This Skill
Activate for:
- Diagram creation requests (e.g., "Create a sequence diagram showing authentication flow")
- Code architecture visualization (e.g., "Create deployment diagram for my Spring Boot app")
.puml file to image conversion
- Markdown files containing ```puml code blocks or linked .puml files
- Confluence or Notion markdown preparation (documents with PlantUML diagrams require conversion first)
- Specific diagram types: UML (sequence, class, activity, state, component, deployment, use case, object, timing) or non-UML (ER, Gantt, mindmap, WBS, JSON/YAML, network, Archimate, wireframes)
- PlantUML syntax validation
Confluence/Notion uploads: If markdown contains PlantUML diagrams, run conversion FIRST before upload.
Prerequisites
Before creating diagrams, verify the PlantUML setup:
python scripts/check_setup.py
Required components:
Creating Diagrams
Diagram Type Identification
Identify the appropriate diagram type based on user intent:
| User Intent | Diagram Type | Reference |
|---|
| Interactions over time | Sequence | references/sequence_diagrams.md |
| System structure with classes | Class | references/class_diagrams.md |
| Workflows, decision flows | Activity | references/activity_diagrams.md |
| Object states and transitions | State | references/state_diagrams.md |
| Database schemas | ER (Entity Relationship) | references/er_diagrams.md |
| Project timelines | Gantt | references/gantt_diagrams.md |
| Idea organization | MindMap | references/mindmap_diagrams.md |
| System architecture | Component | references/component_diagrams.md |
| Actors and features | Use Case | references/use_case_diagrams.md |
| All 19 types | See navigation hub | references/toc.md |
Syntax resources:
references/toc.md: Navigation hub linking to all diagram types
references/common_format.md: Universal elements (delimiters, metadata, comments, notes)
references/styling_guide.md: Modern <style> syntax for visual customization
Resilient Workflow (Primary - Recommended)
For reliable diagram generation with error recovery, follow the 4-step resilient workflow:
Step 1: Identify Diagram Type & Load Reference
- Identify diagram type from user intent
- Load
references/[diagram_type]_diagrams.md for syntax guide
- Consult
references/toc.md if ambiguous
Step 2: Create File with Structured Naming
./diagrams/<markdown_name>_<num>_<type>_<title>.puml
Example: ./diagrams/architecture_001_sequence_user_auth.puml
Step 3: Convert with Error Handling (max 3 retries)
If conversion fails:
- Check
references/troubleshooting/toc.md for error classification
- Load specific guide from
references/troubleshooting/[category]_guide.md
- Check
references/common_syntax_errors.md for diagram type
Step 4: Validate & Integrate
- Verify image file exists
- Add image link:

- Keep .puml source file for future edits
Full documentation: references/workflows/resilient-execution-guide.md
Quick Syntax Reference
Common elements:
- Delimiters:
@startuml / @enduml (required)
- Comments:
' Single line or /' Multi-line '/
- Relationships:
-> (solid), --> (dashed), ..> (dotted)
- Labels:
A -> B : Label text
Minimal examples (see references/[type]_diagrams.md for comprehensive syntax):
' Sequence: references/sequence_diagrams.md
@startuml
Alice -> Bob: Request
Bob --> Alice: Response
@enduml
' Class: references/class_diagrams.md
@startuml
class Animal { +move() }
class Dog extends Animal { +bark() }
@enduml
' ER: references/er_diagrams.md
@startuml
entity User { *id: int }
entity Post { *id: int }
User ||--o{ Post
@enduml
Converting Source Code to Diagrams
The examples/ directory contains language-specific templates for converting common application architectures:
| Application Type | Directory | Key Diagrams |
|---|
| Spring Boot | examples/spring-boot/ | Deployment, Component, Sequence |
| FastAPI | examples/fastapi/ | Deployment, Component (async routers) |
| Python ETL | examples/python-etl/ | Architecture with Airflow |
| Node.js | examples/nodejs-web/ | Express/Nest.js components |
| React | examples/react-frontend/ | SPA deployment, component architecture |
Workflow:
- Identify application type
- Review example in
examples/[app-type]/
- Map code structure to diagram patterns
- Copy and adapt the example
.puml file
- Use Unicode symbols from
references/unicode_symbols.md for semantic clarity
Converting Diagrams to Images
Convert Standalone .puml Files
python scripts/convert_puml.py diagram.puml
python scripts/convert_puml.py diagram.puml --format svg
python scripts/convert_puml.py diagram.puml --format svg --output-dir images/
Extract and Convert from Markdown
CRITICAL for Confluence/Notion: Run this FIRST before upload if markdown contains PlantUML diagrams.
python scripts/process_markdown_puml.py article.md
python scripts/process_markdown_puml.py article.md --format svg
python scripts/process_markdown_puml.py article.md --validate
Outputs:
article_with_images.md: Markdown with image links
images/: Directory with generated images
IDE-Friendly Workflow: Keep diagrams as .puml files during development for IDE preview, then convert for publication.
Direct Command-Line Usage
java -jar ~/plantuml.jar diagram.puml
java -jar ~/plantuml.jar --svg --output-dir out/ diagram.puml
java -jar ~/plantuml.jar "**/*.puml" --svg
See references/plantuml_reference.md for comprehensive command-line options.
Best Practices
Diagram Quality:
- Use descriptive filenames from diagram content
- Add comments with
' for clarity
- Follow standard UML notation
- Test incrementally before adding complexity
Format Selection:
- PNG: Web publishing, smaller files, fixed resolution
- SVG: Documentation, scalable, supports hyperlinks
Styling: Apply modern <style> syntax from references/styling_guide.md:
@startuml
<style>
classDiagram {
class { BackgroundColor LightBlue }
}
</style>
' diagram content
@enduml
Themes: !theme cerulean (also: bluegray, plain, sketchy, amiga)
Unicode symbols: Add semantic meaning with symbols from references/unicode_symbols.md:
node "☁️ AWS Cloud" as aws
database "💾 PostgreSQL" as db
Troubleshooting
Quick diagnosis:
- Check syntax:
java -jar plantuml.jar --check-syntax file.puml
- Identify error type
- Load troubleshooting guide:
references/troubleshooting/toc.md
Common issues:
| Issue | Solution |
|---|
| "plantuml.jar not found" | Download from https://plantuml.com/download, set PLANTUML_JAR |
| "Graphviz not found" | Install from https://graphviz.org/download/ |
| "Syntax Error" | Check delimiters match, consult references/common_format.md |
| "Java not found" | Install Java JRE/JDK 8+, verify with java -version |
Comprehensive guides (215+ errors documented):
references/troubleshooting/toc.md - Navigation hub with error decision tree
references/troubleshooting/[category]_guide.md - 12 focused guides by error type
References
Core Syntax References
| Resource | Purpose |
|---|
references/toc.md | Navigation hub for all 19 diagram types |
references/common_format.md | Universal elements (delimiters, metadata, comments) |
references/styling_guide.md | Modern <style> syntax with CSS-like rules |
references/plantuml_reference.md | Installation, CLI, and troubleshooting |
Troubleshooting Guides
| Resource | Coverage |
|---|
references/troubleshooting/toc.md | Navigation hub with error decision tree |
references/troubleshooting/installation_setup_guide.md | Setup problems |
references/troubleshooting/general_syntax_guide.md | Syntax errors |
references/troubleshooting/[diagram_type]_guide.md | Diagram-specific errors |
Enrichment Resources
| Resource | Purpose |
|---|
references/unicode_symbols.md | Unicode symbols for semantic enrichment |
examples/[framework]/ | Code-to-diagram patterns |
Summary
- Verify setup:
python scripts/check_setup.py
- Navigate types: Start with
references/toc.md
- Learn syntax: Open
references/[diagram_type]_diagrams.md
- Apply styling: Use
references/styling_guide.md
- Add symbols: Use
references/unicode_symbols.md
- Convert files:
scripts/convert_puml.py
- Process markdown:
scripts/process_markdown_puml.py
- Troubleshoot:
references/troubleshooting/toc.md
Supported diagrams:
- UML: sequence, class, activity, state, component, deployment, use case, object, timing
- Non-UML: ER, Gantt, mindmap, WBS, JSON/YAML, network, Archimate, wireframes