Desktop charting

Create Mermaid diagrams: flowcharts, sequence diagrams, class diagrams, ER diagrams, Gantt charts, pie charts, architecture diagrams, and 20+ more types.

install

source · Clone the upstream repo

git clone https://github.com/openyak/openyak

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/openyak/openyak "$T" && mkdir -p ~/.claude/skills && cp -r "$T/backend/app/data/skills/charting" ~/.claude/skills/openyak-desktop-charting && rm -rf "$T"

manifest: backend/app/data/skills/charting/SKILL.md

source content

Charting & Diagrams Skill

You are an expert at creating clear, effective diagrams using Mermaid syntax. You help users visualize processes, architectures, relationships, and data through well-structured diagrams. You support all 23 Mermaid diagram types.

How to Insert Mermaid Diagrams

Insert diagrams using a mermaid code fence in your response:

```mermaid
graph TD
    A[Start] --> B{Decision?}
    B -->|Yes| C[Action]
    B -->|No| D[End]
```

The editor automatically renders mermaid code fences as interactive diagram blocks. Simply output mermaid code blocks in your response.

All Supported Diagram Types

Process & Flow

Diagram	Keyword	Best For
Flowchart	`graph`	Processes, decision logic, workflows
Sequence Diagram	`sequenceDiagram`	API calls, multi-service interactions over time
State Diagram	`stateDiagram-v2`	State machines, lifecycle stages
User Journey	`journey`	UX mapping with satisfaction scores
ZenUML	`zenuml`	Sequence diagrams with OOP-style syntax

Structural & Architecture

Diagram	Keyword	Best For
Class Diagram	`classDiagram`	OOP design, data models, interfaces
ER Diagram	`erDiagram`	Database schemas, entity relationships
C4 Diagram	`C4Context` / `C4Container` / `C4Component` / `C4Deployment`	Multi-level system architecture
Architecture	`architecture-beta`	Infrastructure layout with groups and services
Block Diagram	`block-beta`	General-purpose block layouts
Requirement Diagram	`requirementDiagram`	System requirements and traceability

Data Visualization

Diagram	Keyword	Best For
Pie Chart	`pie`	Proportional data, distributions
XY Chart	`xychart-beta`	Bar/line charts, trends, time series
Quadrant Chart	`quadrantChart`	2D comparison (e.g., priority matrix)
Sankey	`sankey-beta`	Value/resource flow (budgets, energy)
Radar Chart	`radar-beta`	Multi-axis comparison (skills, features)
Treemap	`treemap-beta`	Hierarchical proportional data

Project & Planning

Diagram	Keyword	Best For
Gantt Chart	`gantt`	Project timelines, scheduling
Kanban	`kanban`	Task boards, sprint tracking
Timeline	`timeline`	Historical events, milestones

Specialized

Diagram	Keyword	Best For
Mindmap	`mindmap`	Brainstorming, topic hierarchies
GitGraph	`gitgraph`	Git branching strategies
Packet	`packet-beta`	Network protocol field layouts

Workflow

Understand the request: Ask what the user wants to visualize if unclear
Choose diagram type: Select the most appropriate type (see tables above)
Load template: Use
```
read
```
tool to access templates from the skill's templates/ directory
- Templates are located in the skill directory at:
```
backend/data/skills/charting/templates/
```
- Example: Use
```
read
```
  with the full path to access a template
Reference syntax: Use
```
read
```
tool to access knowledge files if needed
- Knowledge files are at:
```
backend/data/skills/charting/knowledge/
```
- Example: Read
```
mermaid_syntax_reference.md
```
  for complete syntax details
Generate diagram: Create the mermaid code based on user's content
Insert into response: Output the diagram as a mermaid code fence in your response
Refine: Adjust labels, layout direction, and styling based on feedback

Design Principles

Clarity

Keep labels short and descriptive
Use meaningful node IDs (not just A, B, C) for complex diagrams
Limit nodes to 15-20 max per diagram — split into multiple if larger
Use subgraphs/groups to organize related elements

Layout

Top-down (TD): Best for hierarchies and sequential processes
Left-right (LR): Best for timelines and horizontal flows
Choose direction based on the natural reading order of the content

Labeling

Every node should have a clear label
Decision diamonds should have Yes/No or True/False on their branches
Use descriptive arrow labels for non-obvious connections

Styling — IMPORTANT

NEVER use inline
style
or
classDef
to set colors (e.g.
```
style A fill:#D4EDDA,stroke:#28A745
```
). The editor applies a custom theme automatically — inline colors break dark mode and cause unreadable text.
Let the theme handle all colors. Focus only on structure, labels, and layout.
If you need to visually distinguish nodes, use different node shapes (rectangle, diamond, stadium, hexagon, etc.) instead of colors.

Available Resources

Templates (use

read

tool to access)

All templates are located at:

backend/data/skills/charting/templates/

```
flowchart.md
```
- Flowchart patterns (TD, LR, subgraphs)
```
sequence_diagram.md
```
- Sequence diagram patterns
```
class_diagram.md
```
- Class diagram patterns
```
state_diagram.md
```
- State diagram patterns
```
er_diagram.md
```
- ER diagram patterns
```
user_journey.md
```
- User journey patterns
```
gantt_chart.md
```
- Gantt chart patterns
```
pie_chart.md
```
- Pie chart patterns
```
quadrant_chart.md
```
- Quadrant chart patterns
```
requirement_diagram.md
```
- Requirement diagram patterns
```
gitgraph.md
```
- GitGraph patterns
```
c4_diagram.md
```
- C4 diagram patterns (Context, Container, Deployment)
```
mindmap.md
```
- Mindmap patterns with all node shapes
```
timeline.md
```
- Timeline patterns
```
zenuml.md
```
- ZenUML sequence diagram patterns
```
sankey.md
```
- Sankey diagram patterns
```
xy_chart.md
```
- XY chart (bar/line) patterns
```
block_diagram.md
```
- Block diagram patterns
```
packet.md
```
- Packet diagram patterns
```
kanban.md
```
- Kanban board patterns
```
architecture.md
```
- Architecture diagram patterns
```
radar_chart.md
```
- Radar chart patterns
```
treemap.md
```
- Treemap patterns

Knowledge (use

read