Timeline Builder Skill | Agent Skills

Timeline Builder

Generate beautiful interactive timeline HTML pages from JSON configuration data, with three layout modes:

Vertical layout (vertical) — A classic top-to-bottom timeline with event cards alternating on either side of the axis
Horizontal layout (horizontal) — A horizontally scrollable timeline, best for displaying fewer events
Dual-side layout (dual-side) — Events are placed on the left or right based on the side field, great for side-by-side comparisons

All layouts support:

Click to expand/collapse event details
Mobile-friendly responsive design
Custom theme colors, icons, and category labels
Pure static HTML with zero dependencies — opens directly in any browser

Usage

Basic: Generate from a JSON config file

python3 scripts/generate_timeline.py --config timeline_data.json --output timeline.html

Read JSON from stdin

cat timeline_data.json | python3 scripts/generate_timeline.py --stdin --output timeline.html

Override layout mode (takes precedence over config file)

python3 scripts/generate_timeline.py --config data.json --layout horizontal --output timeline.html

JSON Configuration Format

{
  "title": "Project Milestones",
  "layout": "vertical",
  "theme": {
    "primaryColor": "#2563eb",
    "secondaryColor": "#7c3aed",
    "backgroundColor": "#ffffff",
    "textColor": "#1f2937",
    "lineColor": "#d1d5db",
    "fontFamily": "system-ui, -apple-system, sans-serif"
  },
  "events": [
    {
      "date": "2024-01-15",
      "title": "Project Kickoff",
      "summary": "Approval completed, core team assembled",
      "details": "Detailed description text, shown when the card is expanded...",
      "icon": "🚀",
      "category": "Milestone",
      "color": "#10b981",
      "side": "left"
    }
  ]
}

CLI Arguments

| Argument | Description | |----------|-------------| | --config, -c | Path to the JSON config file (mutually exclusive with --stdin) | | --stdin | Read JSON from standard input | | --output, -o | Output HTML file path (defaults to stdout) | | --layout, -l | Override layout mode: vertical, horizontal, dual-side | | --title, -t | Override the timeline title |

Event Fields

| Field | Required | Description | |-------|----------|-------------| | date | Yes | Date label — any format works (e.g. 2024-01, Q1 2024, Phase One) | | title | Yes | Event title | | summary | No | Short description, always visible on the card | | details | No | Detailed content, revealed on click | | icon | No | Emoji or single-character icon (defaults to ●) | | category | No | Category tag displayed on the card | | color | No | Event node color (overrides the theme color) | | side | No | Only for dual-side layout: left or right |

Use Cases

Project milestone displays
Product release histories
Company growth timelines
Personal resume timelines
Course syllabus outlines
Any scenario requiring chronological information display

Dependencies

Python 3.6+ (standard library only — no extra packages required)

Agent Skills: Timeline Builder

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