Edit the JSON spec on the left — the animation updates in real time.
Describe what you want to animate. The button copies a prompt that teaches Claude the spec format with real examples; paste it into a new Claude conversation, then paste the JSON it returns into the editor.
The skill gives Claude the same knowledge permanently, plus a validator and a link generator: Claude checks its own spec and answers with a link that opens it right here. Upload the zip in claude.ai (Settings → Capabilities → Skills), or unzip it into ~/.claude/skills/ for Claude Code.