Imported from David-Li0406/meta-skill-evloving (skill-flow/data/skills-refined-autoskill-36k/skillsmp/graph-easy/SKILL.md). Install upstream with npx skills add David-Li0406/meta-skill-evloving --skill graph-easy. Copyright stays with the author.

Graph-Easy Diagram Skill

Create ASCII architecture diagrams for any GitHub Flavored Markdown file using graph-easy. Pure text output with automatic layout - no image rendering required.

When to Use This Skill

• Adding diagrams to README files
• Design specification documentation
• Any GFM markdown file needing architecture visualization
• Creating flowcharts, pipelines, or system diagrams
• User mentions "diagram", "ASCII diagram", "graph-easy", or "architecture chart"

NOT for ADRs - Use adr-graph-easy-architect for Architecture Decision Records (includes ADR-specific patterns like 2-diagram requirement and before/after templates).

Preflight Check

Run these checks in order. Each layer depends on the previous.

Layer 1: Package Manager

/usr/bin/env bash << 'SETUP_EOF'
# Detect OS and set package manager
case "$(uname -s)" in
  Darwin) PM="brew" ;;
  Linux)  PM="apt" ;;
  *)      echo "ERROR: Unsupported OS (require macOS or Linux)"; exit 1 ;;
esac
command -v $PM &>/dev/null || { echo "ERROR: $PM not installed"; exit 1; }
echo "✓ Package manager: $PM"
SETUP_EOF

Layer 2: Perl + cpanminus (mise-first approach)

# Prefer mise for unified tool management
if command -v mise &>/dev/null; then
  # Install Perl via mise
  mise which perl &>/dev/null || mise install perl
  # Install cpanminus under mise perl
  mise exec perl -- cpanm --version &>/dev/null 2>&1 || {
    echo "Installing cpanminus under mise perl..."
    mise exec perl -- curl -L https://cpanmin.us | mise exec perl -- perl - App::cpanminus
  }
  echo "✓ cpanminus installed (via mise perl)"
else
  # Fallback: Install cpanminus via system package manager
  command -v cpanm &>/dev/null || {
    echo "Installing cpanminus via $PM..."
    case "$PM" in
      brew) brew install cpanminus ;;
      apt)  sudo apt install -y cpanminus ;;
    esac
  }
  echo "✓ cpanminus installed"
fi

Layer 3: Graph::Easy Perl module

# Check if Graph::Easy is installed (mise-first)
if command -v mise &>/dev/null; then
  mise exec perl -- perl -MGraph::Easy -e1 2>/dev/null || {
    echo "Installing Graph::Easy via mise perl cpanm..."
    mise exec perl -- cpanm Graph::Easy
  }
  echo "✓ Graph::Easy installed (via mise perl)"
else
  perl -MGraph::Easy -e1 2>/dev/null || {
    echo "Installing Graph::Easy via cpanm..."
    cpanm Graph::Easy
  }
  echo "✓ Graph::Easy installed"
fi

Layer 4: Verify graph-easy is in PATH

# Verify graph-easy is accessible and functional
command -v graph-easy &>/dev/null || {
  echo "ERROR: graph-easy not found in PATH"
  exit 1
}
# Test actual functionality (--version hangs waiting for stdin AND exits with code 2)
echo "[Test] -> [OK]" | graph-easy &>/dev/null && echo "✓ graph-easy ready"

All-in-One Preflight Script

/usr/bin/env bash << 'PREFLIGHT_EOF'
# Copy-paste this entire block to ensure graph-easy is ready (macOS + Linux)
# Prefers mise for unified cross-platform tool management

# Check for mise first (recommended)
if command -v mise &>/dev/null; then
  echo "Using mise for Perl management..."
  mise which perl &>/dev/null || mise install perl
  mise exec perl -- cpanm --version &>/dev/null 2>&1 || \
    mise exec perl -- curl -L https://cpanmin.us | mise exec perl -- perl - App::cpanminus
  mise exec perl -- perl -MGraph::Easy -e1 2>/dev/null || mise exec perl -- cpanm Graph::Easy
else
  # Fallback: system package manager
  echo "💡 Tip: Install mise for unified tool management: curl https://mise.run | sh"
  case "$(uname -s)" in
    Darwin) PM="brew" ;;
    Linux)  PM="apt" ;;
    *)      echo "ERROR: Unsupported OS"; exit 1 ;;
  esac
  command -v $PM &>/dev/null || { echo "ERROR: $PM not installed"; exit 1; }
  command -v cpanm &>/dev/null || { [ "$PM" = "apt" ] && sudo apt install -y cpanminus || brew install cpanminus; }
  perl -MGraph::Easy -e1 2>/dev/null || cpanm Graph::Easy
fi

# Verify graph-easy is in PATH and functional
command -v graph-easy &>/dev/null || {
  echo "ERROR: graph-easy not in PATH after installation"
  exit 1
}
# Test actual functionality (--version hangs waiting for stdin AND exits with code 2)
echo "[Test] -> [OK]" | graph-easy &>/dev/null && echo "✓ graph-easy ready"
PREFLIGHT_EOF

Part 1: DSL Syntax

Basic Elements

# Nodes (square brackets)
[Node Name]

# Edges (arrows)
[A] -> [B]

# Labeled edges
[A] -- label --> [B]

# Bidirectional
[A] <-> [B]

# Chain
[A] -> [B] -> [C]

Groups (Containers)

# Named group with dashed border
( Group Name:
  [Node A]
  [Node B]
)

# Nested connections
( Frontend:
  [React App]
  [API Client]
)
( Backend:
  [API Server]
  [Database]
)
[API Client] -> [API Server]

Node Labels

# Custom label (different from ID)
[db] { label: "PostgreSQL Database"; }

# ASCII markers for visual distinction INSIDE boxes
# (emojis break box alignment - use ASCII markers instead)
[deleted] { label: "[x] Old Component"; }
[added] { label: "[+] New Component"; }
[warning] { label: "[!] Deprecated"; }
[success] { label: "[OK] Passed"; }

Character rules for nodes:

• Graphical emojis (rocket, bulb, checkmark) - NEVER (double-width breaks box alignment)
• Unicode symbols (check, cross, arrow) - OK (single-width, safe)
• ASCII markers ([x] [+] [!] :) ) - ALWAYS safe (monospace)

Use graph { label: "..."; } for graphical emojis in title/legend.

Example: Emoji breaks alignment (DON'T DO THIS)

# BAD - emoji inside node
[rocket] { label: "Launch"; }

Renders broken:

+----------------+
| Launch         |   <-- box edge misaligned due to double-width emoji
+----------------+

Example: ASCII marker preserves alignment (DO THIS)

# GOOD - ASCII marker inside node
[rocket] { label: "[>] Launch"; }

Renders correctly:

+--------------+
| [>] Launch   |
+--------------+

Flow Direction (MANDATORY: Always specify)

# MANDATORY: Always specify flow direction explicitly
graph { flow: south; }   # Top-to-bottom (architecture, decisions)
graph { flow: east; }    # Left-to-right (pipelines, sequences)

Never rely on default flow - explicit is clearer.

Graph Title and Legend (Outside Boxes - Emojis Safe Here)

Emojis break alignment INSIDE boxes but are SAFE in graph titles/legends.

Emoji Selection Guide - Choose emoji that matches diagram purpose:

# Title with semantic emoji
graph { label: "Deployment Pipeline"; flow: east; }

# Title with legend (multiline using \n)
graph { label: "Hook Flow\n----------\nAllow  Deny  Warn"; flow: south; }

Node Styling (Best Practices)

# Rounded corners for start/end nodes
[ Start ] { shape: rounded; }
[ End ] { shape: rounded; }

# Double border for emphasis
[ Critical Step ] { border: double; }

# Bold border for important nodes
[ Key Decision ] { border: bold; }

# Dotted border for optional/skippable
[ Optional ] { border: dotted; }

# Multiline labels with \n
[ Hook Input\n(stdin JSON) ]

Rendered examples:

+----------+              +---------+
| Rounded  |              | Default |
+----------+              +---------+

+==========+              +=========+
| Double   |              |  Bold   |
+==========+              +=========+

Note: Dotted borders ({ border: dotted; }) use special characters that render inconsistently on GitHub. Use sparingly.

Edge Styles

[ A ] -> [ B ]      # Solid arrow (default)
[ A ] ..> [ B ]     # Dotted arrow
[ A ] ==> [ B ]     # Bold/double arrow
[ A ] - -> [ B ]    # Dashed arrow
[ A ] -- label --> [ B ]  # Labeled edge

Part 2: Common Diagram Patterns

Pipeline (Left-to-Right)

graph { flow: east; }
[Input] -> [Process] -> [Output]

Multi-Component System

graph { flow: south; }
[API Gateway] -> [Service A]
[API Gateway] -> [Service B]
[Service A] -> [Database]
[Service B] -> [Database]

Decision with Options

graph { flow: south; }
[Decision] -> [Option A]
[Decision] -> [Option B]
[Decision] -> [Option C]

Grouped Components

( Frontend:
  [React App]
  [Vue App]
)
( Backend:
  [API Server]
  [Worker]
)
[React App] -> [API Server]
[Vue App] -> [API Server]
[API Server] -> [Worker]

Bidirectional Flow

[Client] <-> [Server]
[Server] -> [Database]

Layered Architecture

graph { flow: south; }
( Presentation:
  [UI Components]
)
( Business:
  [Services]
)
( Data:
  [Repository]
  [Database]
)
[UI Components] -> [Services]
[Services] -> [Repository]
[Repository] -> [Database]

Part 3: Rendering

Command (Platform-Aware)

# For GitHub markdown (RECOMMENDED) - renders as solid lines
graph-easy --as=ascii << 'EOF'
graph { flow: south; }
[A] -> [B] -> [C]
EOF

# For terminal/local viewing - prettier Unicode lines
graph-easy --as=boxart << 'EOF'
graph { flow: south; }
[A] -> [B] -> [C]
EOF

Output Modes

Why ASCII for GitHub? GitHub's markdown preview renders Unicode box-drawing characters (┌─┐│└─┘) as dotted lines, breaking the visual appearance. Pure ASCII (+---+, |) renders correctly as solid lines on all platforms.

Validation Workflow

# 1. Write DSL to heredoc
# 2. Render with ascii (for GitHub) or boxart (for terminal)
graph-easy --as=ascii << 'EOF'
[Your] -> [Diagram] -> [Here]
EOF

# 3. Review output
# 4. Iterate if needed
# 5. Copy final output to markdown
# 6. Validate alignment (RECOMMENDED)

Post-Generation Alignment Validation (Recommended)

After embedding diagram in markdown, validate alignment to catch rendering issues.

Use the doc-tools plugin skill:

Skill: doc-tools:ascii-diagram-validator

Or invoke directly: Skill(doc-tools:ascii-diagram-validator) with the target file path.

Why validate?

• Catches copy-paste alignment drift
• Detects font rendering issues
• Ensures vertical columns align properly
• Graph-easy output is machine-aligned, but manual edits can break it

When to skip: If diagram was just generated by graph-easy and not manually edited, validation is optional (output is inherently aligned).

Part 4: Embedding in Markdown

Markdown Format (MANDATORY: Always Include Source)

CRITICAL: Every rendered diagram MUST be followed by a collapsible <details> block containing the graph-easy source code. This is non-negotiable for:

• Reproducibility: Future maintainers can regenerate the diagram
• Editability: Source can be modified and re-rendered
• Auditability: Changes to diagrams are trackable in git diffs

## Architecture

```
+----------+     +----------+     +----------+
|  Input   | --> | Process  | --> |  Output  |
+----------+     +----------+     +----------+
```

<details>
<summary>graph-easy source</summary>

```
graph { flow: east; }
[Input] -> [Process] -> [Output]
```

</details>

The <details> block is MANDATORY - never embed a diagram without its source.

GFM Collapsible Section Syntax

GitHub Flavored Markdown supports HTML <details> and <summary> tags for collapsible sections. Key syntax rules:

Structure:

<details>
  <summary>Click to expand</summary>

  <!-- BLANK LINE REQUIRED HERE -->
  Content goes here (Markdown supported)
  <!-- BLANK LINE REQUIRED HERE -->
</details>

Critical rules:

1. Blank lines required - Must have empty line after <summary> and before </details> for Markdown to render
2. No indentation - <details> and <summary> must be at column 0 (no leading spaces)
3. Summary is clickable label - Text in <summary> appears as the collapsed header
4. Markdown inside works - Code blocks, headers, lists all render correctly inside

Optional: Default expanded:

<details open>
  <summary>Expanded by default</summary>

  Content visible on page load
</details>

Common mistake (Markdown won't render):

<details>
  <summary>Broken</summary>
  No blank line - this won't render as Markdown!
</details>

References:

• GitHub Docs: Collapsed sections

Regeneration

If the markdown changes, regenerate by running the source through graph-easy again:

# Extract source from <details> block, pipe through graph-easy
graph-easy --as=boxart << 'EOF'
# paste source here
EOF

Reference: Monospace-Safe Symbols

Avoid emojis - they have variable width and break box alignment on GitHub.

Status Markers

Box Drawing (U+2500-257F)

- | + + + + + + + + +   (light)
= | + + + + + + + + +   (double)

Arrows & Pointers

-> <- up down            (arrows)
v ^                      (logic - graph-easy uses these)
< > ^ v                  (ASCII arrows)

Shapes & Bullets

* o O                    (bullets)
[ ] #                    (squares)
< > <>                   (diamonds)

Graph Label (MANDATORY: EVERY diagram MUST have emoji + title)

WARNING: This is the most commonly forgotten requirement. Diagrams without labels are invalid.

Correct Example

graph { label: "🚀 Deployment Pipeline"; flow: east; }
[Build] -> [Test] -> [Deploy]

Anti-Pattern (INVALID - DO NOT DO THIS)

graph { flow: east; }
[Build] -> [Test] -> [Deploy]

Why this is wrong: Missing label: with emoji. Every diagram needs context at a glance.

Mandatory Checklist (Before Rendering)

Graph-Level (MUST have)

• graph { label: "🚀 Title"; } - semantic emoji + title (MOST FORGOTTEN - check first!)
• graph { flow: south; } or graph { flow: east; } - explicit direction
• Command uses --as=ascii for GitHub markdown (or --as=boxart for terminal only)

Embedding (MUST have - non-negotiable)

• <details> block with source - EVERY diagram MUST have collapsible source code block
• Format: rendered diagram in code block, followed immediately by <details><summary>graph-easy source</summary> with source in code block
• Never commit a diagram without its reproducible source

Post-Embedding Validation (Recommended)

• Run ascii-diagram-validator on the file after embedding diagram
• Especially important if diagram was manually edited after generation
• Catches alignment drift from copy-paste or font rendering issues

Node Styling (Visual hierarchy)

• Start/end nodes: { shape: rounded; } - entry/exit points
• Critical/important nodes: { border: double; } or { border: bold; }
• Optional/skippable nodes: { border: dotted; }
• Default nodes: no styling (standard border)
• Long labels use \n for multiline - max ~15 chars per line

Edge Styling (Semantic meaning)

• Main/happy path: -> solid arrow
• Conditional/alternate: ..> dotted arrow
• Emphasized/critical: ==> bold arrow
• Edge labels are SHORT (1-3 words): -- YES -->, -- error -->

Character Safety (Alignment)

• NO graphical emojis inside nodes (break alignment)
• Unicode symbols OK inside nodes (single-width)
• ASCII markers ALWAYS safe ([x] [+] [!] [OK])
• Graphical emojis ONLY in graph { label: "..."; } title

Structure (Organization)

• Groups ( Name: ... ) used for logical clustering when 4+ related nodes
• Node IDs short, labels descriptive: [db] { label: "PostgreSQL"; }
• No more than 7-10 nodes per diagram (split if larger)

Success Criteria

Correctness

1. Parses without error - graph-easy accepts the DSL
2. Renders cleanly - no misaligned boxes or broken lines
3. Matches content - all key elements from description represented
4. Source preserved (MANDATORY) - EVERY diagram MUST have <details> block with graph-easy DSL source immediately after the rendered output

Aesthetics

1. Platform-appropriate output - --as=ascii for GitHub (solid lines), --as=boxart for terminal only
2. Readable labels - multiline with \n, no truncation
3. Clear flow - direction matches natural reading (top-down or left-right)
4. Consistent styling - same border style = same semantic meaning throughout

Comprehensiveness

1. Edge semantics - solid=normal, dotted=conditional, bold=critical
2. Logical grouping - related nodes in ( Group: ... ) containers

Troubleshooting

Resources

• Graph::Easy on CPAN
• Graph::Easy Manual
• Graph::Easy GitHub