creating-mermaid-diagrams

This skill acts as a specialized assistant for developers, architects, and technical writers who need to create high-quality, GitHub-compatible visual documentation. It streamlines the process of writing, styling, and validating Mermaid diagrams by providing a structured design philosophy and professional-grade color palettes that ensure legibility in both GitHub light and dark modes. The skill covers a vast array of diagram types including flowcharts, sequence diagrams, class models, ER diagrams, state machines, and project management visualizations like Gantt and Kanban boards.

• Full support for all standard Mermaid.js diagram types, including complex options like C4Context, architecture-beta, and mindmaps.

• Built-in design system that enforces accessibility standards, requiring accTitle and accDescr for every diagram generated.

• Extensive library of 24 pre-configured, battle-tested color themes (e.g., Catppuccin, Nord, Tokyo Night) to ensure visual consistency.

• Local preview capabilities via mermaid-cli (mmdc), allowing for SVG and PNG export for rapid iteration.

• Gist-based integration to preview how diagrams will render directly within GitHub pull requests, issues, and Markdown files before final commitment.

• Automated style guidance to prioritize structure, logical edge weights, and semantic coloring over aesthetic clutter.

• Use this skill whenever you need to clarify system architecture, document API request sequences, map out complex decision trees, or visualize database schemas.

• Ensure all node IDs are written in snake_case and use quoted labels for special characters to prevent rendering failures on the GitHub platform.

• Utilize the preview.sh script to switch between dark and light modes during the design process to guarantee accessibility for all repository contributors.

• Be aware of rendering constraints: avoid complex nested subgraphs beyond two levels, keep node counts below 100 for optimal performance, and note that click events and custom HTML/CSS are not supported by the native GitHub renderer.