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Diagram To Image

  • 466 installs
  • 130 repo stars
  • Updated June 19, 2026
  • sugarforever/01coder-agent-skills

diagram-to-image is a Claude Code skill with a Node CLI that renders Mermaid diagrams or markdown tables to PNG from the terminal for developers creating README, spec, and launch documentation assets.

About

diagram-to-image is a Claude Code skill bundling a Node.js CLI that converts Mermaid diagrams and markdown tables into PNG images from the terminal. The CLI accepts an input file and required -o output flag, auto-detecting content type or forcing mermaid or table mode explicitly. It supports 10 visual themes including default, dark, forest, and blueprint, plus scale factors from 1 to 4 with a default of 2, configurable background color, and a remote render server defaulting to diagramless.xyz. Developers reach for it when README files, architecture specs, or launch materials need checked-in PNG diagrams without opening a design tool.

  • Node CLI: diagram-to-image with required -o PNG output
  • Auto-detects mermaid vs table via --type auto|mermaid|table
  • 10 named themes (default, dark, forest, neutral, ocean, emerald, midnight, slate, lavender, blueprint)
  • Scale factor 1–4 (default 2) and optional --bg background color
  • Remote render default server https://diagramless.xyz with --server override

Diagram To Image by the numbers

  • 466 all-time installs (skills.sh)
  • +17 installs in the week ending Jul 27, 2026 (Skillselion tracking)
  • Ranked #124 of 550 CLI & Terminal skills by installs in the Skillselion catalog
  • Security screen: LOW risk (skills.sh audit)
  • Data as of Aug 4, 2026 (Skillselion catalog sync)
npx skills add https://github.com/sugarforever/01coder-agent-skills --skill diagram-to-image

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Listed on Skillselion
Installs466
repo stars130
Security audit3 / 3 scanners passed
Last updatedJune 19, 2026
Repositorysugarforever/01coder-agent-skills

How do you render Mermaid diagrams to PNG from the terminal?

Render Mermaid diagrams or markdown tables to PNG from the terminal for READMEs, specs, and launch assets.

Who is it for?

Developers who maintain README and spec diagrams and want repeatable terminal PNG exports without manual screenshotting.

Skip if: Interactive diagram editing or vector SVG output when PNG raster images are not the desired format.

When should I use this skill?

A developer needs to convert a Mermaid file or markdown table to PNG for a README, spec, or launch asset from the CLI.

What you get

PNG image file rendered from Mermaid source or markdown table with chosen theme and scale.

  • PNG diagram image

By the numbers

  • Supports 10 visual themes for PNG output
  • Accepts scale factors 1-4 with default scale 2
  • Handles 3 content types: auto, mermaid, and table

Files

SKILL.mdMarkdownGitHub ↗

Diagram to Image

Convert Mermaid diagrams and Markdown tables to PNG images via the mermaid-red API (diagramless.xyz). Produces high-quality, styled output with custom themes — no heavy local dependencies needed.

When to Use

Use this skill when:

  • User has a Mermaid diagram that needs to be converted to an image
  • User has a Markdown table that needs to be converted to an image
  • User is writing content for X/Twitter and needs visual exports
  • User asks to "convert to image", "export as PNG", "make this an image", or similar

Prerequisites

The bundled script uses Node.js built-in fetch (Node 18+). No npm install needed.

# The render script is bundled with this skill:
SKILL_DIR=~/.claude/skills/diagram-to-image/scripts
ls $SKILL_DIR/diagram-to-image.mjs

Smart Output Location

IMPORTANT: Determine the best output location based on context. Follow this decision tree:

1. User Specifies Path

If user explicitly mentions a path or filename, use that.

2. Project Context Detection

Check for common image/asset directories in the current project:

# Check for existing image directories (in order of preference)
ls -d ./images ./assets ./img ./static ./public/images ./assets/images 2>/dev/null | head -1

Use the first existing directory found. Common patterns:

  • ./images/ - General projects
  • ./assets/ - Web projects
  • ./assets/images/ - Structured web projects
  • ./public/images/ - Next.js, React projects
  • ./static/ - Hugo, other static site generators
  • ./img/ - Short form convention

3. Article/Document Context

If user is writing an article or document:

  • Look for the document's directory
  • Create images/ subdirectory if appropriate
  • Name the image based on the document name + descriptor

4. Conversation Context

Analyze the conversation to determine:

  • What the diagram represents → Use for filename (e.g., auth-flow.png, user-journey.png)
  • Related file being discussed → Place image near that file
  • Topic being discussed → Use for naming

5. Default Fallback

If no context clues:

  • Use current working directory
  • Generate descriptive filename from diagram content

Filename Generation

Create meaningful filenames based on content analysis:

Content PatternExample Filename
flowchart with auth/loginauth-flow.png
sequenceDiagram with APIapi-sequence.png
erDiagramentity-relationship.png
pie chart about Xx-distribution.png
gantt chartproject-timeline.png
Table with comparisoncomparison-table.png
Table with datadata-table.png

Rules:

  • Use kebab-case (lowercase with hyphens)
  • Keep names concise but descriptive (2-4 words)
  • Avoid generic names like diagram.png or image.png
  • Include topic/subject when identifiable

Conversion Process

Step 1: Analyze Context

Before converting, gather context: 1. Check current working directory 2. Look for existing image directories 3. Analyze diagram/table content for naming 4. Consider any files or topics mentioned in conversation

Step 2: Determine Output Path

# Example logic (implement mentally, not as literal script)
if user_specified_path:
    output_path = user_specified_path
elif exists("./images"):
    output_path = "./images/{generated_name}.png"
elif exists("./assets"):
    output_path = "./assets/{generated_name}.png"
elif exists("./public/images"):
    output_path = "./public/images/{generated_name}.png"
else:
    output_path = "./{generated_name}.png"

Step 3: Create Temporary Input File

# For Mermaid diagrams
cat > /tmp/diagram.mmd << 'DIAGRAM_EOF'
<mermaid content>
DIAGRAM_EOF

# For Markdown tables
cat > /tmp/table.md << 'TABLE_EOF'
<table content>
TABLE_EOF

Step 4: Convert via mermaid-red API

The API auto-detects content type (mermaid vs table). Both use the same command.

Using the bundled script:

# Mermaid diagram
node ~/.claude/skills/diagram-to-image/scripts/diagram-to-image.mjs /tmp/diagram.mmd -o <output_path>.png

# Markdown table
node ~/.claude/skills/diagram-to-image/scripts/diagram-to-image.mjs /tmp/table.md -o <output_path>.png

# With custom theme
node ~/.claude/skills/diagram-to-image/scripts/diagram-to-image.mjs /tmp/diagram.mmd -o <output_path>.png --theme ocean

# Force content type (if auto-detect gets it wrong)
node ~/.claude/skills/diagram-to-image/scripts/diagram-to-image.mjs /tmp/table.md -o <output_path>.png --type table

Available options:

  • --theme <name> — default, dark, forest, neutral, ocean, emerald, midnight, slate, lavender, blueprint
  • --type <type> — auto (default), mermaid, table
  • --scale <n> — 1-4 (default: 2, for 2x DPI)
  • --bg <color> — Background color (default: white, use "transparent" for no bg)
  • --server <url> — Override server (default: https://diagramless.xyz)

Piping from stdin also works:

echo "graph TD; A-->B" | node ~/.claude/skills/diagram-to-image/scripts/diagram-to-image.mjs -o out.png
cat /tmp/table.md | node ~/.claude/skills/diagram-to-image/scripts/diagram-to-image.mjs --type table -o table.png

Step 5: Report Result

After conversion, tell the user: 1. Full path where image was saved 2. Why that location was chosen (briefly) 3. File size in bytes (printed by the script) 4. Suggest they can specify a different location if needed

Examples

Example 1: Project with images/ directory

Context: User is in a project that has ./images/ directory, discussing authentication.

User: "Convert this to an image"

flowchart TD
    A[Login] --> B{Valid?}
    B -->|Yes| C[Dashboard]
    B -->|No| D[Error]

Action: 1. Detect ./images/ exists 2. Analyze content → authentication flow 3. Generate filename: login-flow.png 4. Save content to /tmp/diagram.mmd 5. Run: node ~/.claude/skills/diagram-to-image/scripts/diagram-to-image.mjs /tmp/diagram.mmd -o ./images/login-flow.png

---

Example 2: Writing X article about AI with ocean theme

Context: User mentioned writing an article about AI agents for X.

User: "Make this a PNG with ocean theme"

flowchart LR
    User --> Agent --> Tools --> Response

Action: 1. Save content to /tmp/diagram.mmd 2. Run: node ~/.claude/skills/diagram-to-image/scripts/diagram-to-image.mjs /tmp/diagram.mmd -o ./ai-agent-flow.png --theme ocean

---

Example 3: Data comparison table

User: "Export this table as image"

| Model | Speed | Accuracy |
|-------|-------|----------|
| GPT-4 | Slow | High |
| Claude | Fast | High |

Action: 1. Save content to /tmp/table.md 2. Run: node ~/.claude/skills/diagram-to-image/scripts/diagram-to-image.mjs /tmp/table.md -o ./model-comparison.png (auto-detects as table)

---

Example 4: User specifies location

User: "Save this diagram to ~/Desktop/my-chart.png"

Action: Use exactly ~/Desktop/my-chart.png as output path.

Error Handling

  • If the API server is unreachable, the script prints a clear error message
  • If content type auto-detection fails, use --type mermaid or --type table explicitly
  • For local development/testing, use --server http://localhost:3000

Related skills

FAQ

What themes does diagram-to-image support?

diagram-to-image supports 10 themes: default, dark, forest, neutral, ocean, emerald, midnight, slate, lavender, and blueprint. Pass --theme to select one when rendering Mermaid or table input to PNG.

What scale range does diagram-to-image accept?

diagram-to-image accepts scale factors from 1 to 4 via the --scale flag, defaulting to 2. Higher scale produces sharper PNG output for README and spec documentation assets.

Is Diagram To Image safe to install?

skills.sh reports 3 of 3 security scanners passed. Review the Security Audits panel on this page before installing in production.

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