scroll-world

Why it's ranked here

The hard part of this genre is the seam between clips, and the procedure is built around it: joining clips must start and end on frames pulled from the rendered videos, never the original stills, and the docs call a mismatch the most common failure. The player is MIT licensed, has zero dependencies and loads each clip as a whole blob so it never relies on server byte-range support. Costs are measured and stated up front, with a six-scene 1080p chain quoted at about $27 on the default video backend.

What's good

Budget is a gate, not an afterthought: the skill states an estimated total with roughly 15% re-roll headroom and waits for approval before rendering anything. The phone handling is specific: seeks are coalesced so fast flicks cannot freeze the video, the poster stays up until a real frame paints, and reduced-motion visitors get cross-dissolving stills with no video loaded at all. The mobile option renders a separate native portrait chain rather than cropping the landscape film. The encode settings explain why a tighter keyframe interval makes phone scrubbing smoother.

Tradeoffs

Every build spends money on paid generation services: video through Monid by default, scene images through Higgsfield credits or a ChatGPT subscription via the Codex CLI, plus ffmpeg and Python with Pillow locally. Generations take minutes each and run in the background. The mobile version roughly doubles the video spend. The docs say seam behaviour when a chain is finished on a different provider is untested, and no test directory appears among the files.

How to use it well

Fits a marketer or developer who wants one cinematic scrolling hero for a brand and is willing to pay per clip for it. Use the cheap 480p or draft tier to preview the whole journey, approve it, then re-render final legs at full quality. Keep each scene's subject centred, check every clip's last frame before chaining the next, and keep five to seven scenes. It does not cover the rest of a site: the output is a scroll section, not a full page builder.

Observed

License

MIT

Form

Agent skill: a procedure document plus reference scripts, prompt templates and a JavaScript scrub engine

Install surface

Claude Code plugin marketplace, the skills CLI via npx, or manual copy into an agent skills directory

Languages

Markdown instructions, bash scripts, vanilla JavaScript, Python

Runtime dependencies

Monid CLI (default video backend), Higgsfield CLI, ffmpeg and ffprobe, Python 3 with Pillow; Codex CLI optional

Scrub engine dependencies

Zero dependencies; does not require HTTP byte-range support

Accessibility

Under prefers-reduced-motion the engine never loads clips and cross-dissolves the stills

Tests

No test directory among the repository files