chart-image

SKILL.md

Chart Image Generator

Generate PNG chart images from data using Vega-Lite. Perfect for headless server environments.

Why This Skill?

Built for Fly.io / VPS / Docker deployments:

  • No native compilation - Uses Sharp with prebuilt binaries (unlike canvas which requires build tools)
  • No Puppeteer/browser - Pure Node.js, no Chrome download, no headless browser overhead
  • Lightweight - ~15MB total dependencies vs 400MB+ for Puppeteer-based solutions
  • Fast cold starts - No browser spinup delay, generates charts in <500ms
  • Works offline - No external API calls (unlike QuickChart.io)

Setup (one-time)

cd /data/clawd/skills/chart-image/scripts && npm install
Installs
8
First Seen
Apr 7, 2026