mermaid-diagrams_skill

Overview

This skill generates Mermaid diagrams in Markdown for flowcharts, sequence diagrams, ER diagrams, state machines, Gantt charts, class diagrams, git graphs, C4 context diagrams, and more. It produces ready-to-render code blocks that work in GitHub, GitLab, VS Code, Obsidian, Notion, and other Mermaid-capable editors. Use it to convert complex system descriptions, workflows, or data models into clear visualizations quickly.

How this skill works

Provide a description of the system, process, data model, or user flow you want visualized and specify the desired diagram type (or let the skill suggest one). The skill returns a fenced Markdown block with valid mermaid syntax, including node/edge definitions, subgraphs, labels, and optional styling. It follows common patterns and best practices—keeping diagrams focused, using meaningful labels, and choosing appropriate direction and grouping for readability.

When to use it

• Explaining API flows, service interactions, or call sequences
• Designing or documenting database schemas and relationships
• Mapping business processes, decision logic, and algorithms
• Describing component or service architecture and deployments
• Representing state machines, lifecycle transitions, or user journeys

Best practices

• Pick the right diagram type first (flowchart, sequence, erDiagram, classDiagram, stateDiagram-v2, gantt, gitGraph, C4Context).
• Keep each diagram focused on a single concept or interaction to avoid clutter.
• Use descriptive labels for nodes and edges instead of generic letters.
• Group related items with subgraphs and choose direction (LR/TB) that matches the mental model.
• Prefer simple diagrams and break complex systems into multiple coordinated diagrams.

Example use cases

• Generate a flowchart that documents a payment approval workflow with decision nodes and error paths.
• Create a sequenceDiagram showing client->API->auth->DB interactions for an order endpoint.
• Produce an erDiagram for a Postgres schema with PK/FK and cardinality annotations.
• Build a stateDiagram-v2 to model an order lifecycle: Draft → Submitted → Approved/Rejected.
• Render a C4-style context or flowchart with subgraphs to visualize microservice boundaries and data stores.