mermaid-diagramming_skill

Overview

This skill generates Mermaid diagrams directly inside Obsidian notes, covering flowcharts, sequence diagrams, class diagrams, Gantt, state machines, ER diagrams, mindmaps and more. It helps you visualize processes, architectures, timelines and relationships without leaving Obsidian. Use it to create editable, theme-aware diagrams that render in Obsidian's preview mode.

How this skill works

Write fenced code blocks with the language identifier mermaid and paste Mermaid syntax for the diagram type you need. The skill relies on Obsidian's built-in Mermaid renderer, so diagrams adapt to the active Obsidian theme and render in preview/exported notes. Note that Obsidian may use an older Mermaid release and disables JavaScript interactions, so use static Mermaid syntax and explicit styles for consistent results.

When to use it

• Documenting process flows, decision trees, or user journeys inside notes
• Mapping system architectures, service interactions, or deployment diagrams
• Visualizing API calls, sequences, and message flows during design
• Creating class diagrams, ER diagrams, or database schemas for design docs
• Planning projects with Gantt charts or timelines directly in notes

Best practices

• Keep very large diagrams under ~50 nodes or split into multiple diagrams to avoid slow rendering
• Add explicit style rules (fill, stroke, color) when you need consistent colors across light/dark themes
• Use the correct diagram keyword (flowchart, sequenceDiagram, classDiagram, gantt, etc.) for best syntax support
• Export diagrams as PNG/SVG for sharing outside Obsidian since PDF export converts them to images
• Avoid JavaScript-dependent features and click callbacks; rely on static Mermaid features

Example use cases

• A flowchart in a SOP note that documents onboarding steps and decision points
• A sequence diagram showing client-server-database interactions for an API design
• A class diagram in a design doc illustrating object relationships and methods
• A Gantt chart inside a project note to track phases, dependencies, and milestones
• An ER diagram in a data model note describing entities, attributes and cardinality