Obsidian Mermaid Diagrams

Create Mermaid diagrams that render correctly in Obsidian and publish without issues.

When to Use This Skill

Activate when you need to:

• Create flowcharts, sequence diagrams, ER diagrams
• Convert ASCII art to Mermaid
• Fix Mermaid rendering errors in Obsidian

Core Principle: Simplicity First

다이어그램은 한눈에 들어와야 한다

복잡한 다이어그램은 읽기 어렵다. 항상 최소한의 노드와 연결로 핵심만 표현하라.

Node Minimization

Before (9개 노드):

flowchart LR
    A[수집] --> B[정리] --> C[보관]
    D[목표] --> E[학습] --> F[실행] --> G[측정] --> H[달성]

After (2개 노드 – 순차 흐름을 노드 내 텍스트로):

flowchart LR
    A[수집 → 정리 → 보관]
    B[목표 → 학습 → 실행 → 달성]

Connection Minimization

• 핵심 흐름만 표현, 세부사항은 본문에서 설명
• 노드 5개 이하, 연결선 교차 금지
• 복잡한 관계는 여러 개의 단순한 다이어그램으로 분리

Table vs Mermaid 선택

원칙: 같은 정보를 더 컴팩트하게 표현하는 형식 선택

Critical Rules

1. NO Markdown in Labels

Common Errors:

Node["1. First"]     → "Unsupported markdown: list"
Node["Text<br/>More"] → "Unsupported markdown: heading"
Node["## Header"]    → "Unsupported markdown: heading"

Correct:

Node[First]
Node[Text]

Rule: Keep labels plain text. Move complex descriptions outside the diagram.

2. Prefer Square Layout (정사각형 레이아웃)

Problem: flowchart LR은 너무 넓고, flowchart TB는 너무 길어진다.

Solution: TB + 내부 LR 조합으로 정사각형에 가까운 레이아웃 만들기

flowchart TB
    subgraph Layer1["레이어 1"]
        direction LR
        A[항목A] ~~~ B[항목B] ~~~ C[항목C]
    end

    subgraph Layer2["레이어 2"]
        direction LR
        D[항목D] ~~~ E[항목E]
    end

    Layer1 --> Layer2

패턴:

• flowchart TB: 전체 흐름은 위→아래
• direction LR: 각 subgraph 내부는 가로 배치
• ~~~: 보이지 않는 연결 (화살표 없이 정렬용)

Rule: 세로로 너무 길어지면 subgraph + direction LR 사용.

3. Keep Labels Short

❌ Too long:
Node["This is a very long description that will break layout"]

✅ Short and clear:
Node[Short Label]

Rule: Labels should be under 15 characters. Add details in text below the diagram.

4. Avoid Special Characters in Subgraph Names

❌ May cause issues:
subgraph "1. Phase One"
subgraph "Phase: Setup"

✅ Safe:
subgraph Phase_One["Phase One"]
subgraph Setup["Setup Phase"]

Good Examples

Simple Flowchart

flowchart TB
    A[Start] --> B{Decision}
    B -->|Yes| C[Action]
    B -->|No| D[End]

Process Flow with Details Outside

flowchart TB
    Input[Input] --> Process[Process]
    Process --> Output[Output]

Process Details:

• Input: User data from form
• Process: Validation and transformation
• Output: Saved to database

Subgraph Example

flowchart TB
    subgraph Frontend["Frontend"]
        UI[UI] --> API[API Call]
    end
    subgraph Backend["Backend"]
        Server[Server] --> DB[Database]
    end
    API --> Server

Bad Examples (Don’t Do This)

Markdown in Labels

flowchart LR
    A["1. Start<br/>with details"] --> B{"2. Decision"}

This will show “Unsupported markdown” errors.

Too Wide

flowchart LR
    A[Very Long Process Name Here] --> B[Another Long Name] --> C[Yet Another] --> D[And More]

This gets cut off on mobile and narrow screens.

Converting ASCII to Mermaid

ASCII Art:

┌───────┐     ┌───────┐
│ Start │────→│  End  │
└───────┘     └───────┘

Mermaid:

flowchart TB
    Start[Start] --> End[End]

Quality Checklist

Before completing diagram creation:

• No <br/> tags in node labels
• No numbered list format (1., 2.) in labels
• 정사각형 레이아웃: TB + subgraph 내 LR 조합 사용
• All labels are short (under 15 characters)
• Complex details moved to text outside diagram
• No special characters in subgraph names
• Tested rendering in Obsidian preview