Voxel 3D
Sandbox
A free Claude skill for reels Claude narrates itself
Claude tells the story itself. A blocky orange Claude hops along a path of sand discs, one step of the story per disc, while white UI cards build themselves out of flying cubes above it and props blow apart into voxels. It opens on a title card a firecracker sets on fire and ends with the whole path lighting up from above, then a COMMENT keyword built of voxels.
35–55 s9:16 verticalTikTokInstagram ReelsYouTube Shorts
Free · by Casper
What it makes
- A voxel world of round sand discs under a cream sky, built in three.js
- A blocky orange Claude that narrates, lip-syncs and hops from disc to disc
- UI cards and props that build out of cubes and burst apart again
- A step chip and word-by-word captions with the newest word in chartreuse
- A burning title card at the start and a voxel COMMENT keyword at the end
Best for: Step-by-step stories told by Claude itself: setups, workflows, behind the scenes and announcements.
What you need
- Node 22 or newer
- Chrome or Edge
- ffmpeg
- An ElevenLabs API key (the free plan works to try it)
- A graphics card
- three.js (the agent installs it)
35 to 55 seconds · One voice, with free estimated timings before you spend any credits · Rendered on your graphics card, about 4 minutes for a 43-second reel
How to use it
- Morphy: it's built in. Open Settings → Community → Library.md and add Sandbox to a chat in one click.
- Claude Code: save the file as
~/.claude/skills/sandbox/SKILL.md, with the reference frames beside it asreference.jpg, then ask for a video or run/sandbox. - Codex or any other agent: add it as a skill, or attach the file to your first message.
Your first video
Make a 45-second Sandbox reel: how I set Claude up to plan my week, in five steps.
The agent checks your setup, writes the script, makes the voice, renders a few stills to check and then every frame, and hands you the MP4. Posting it is up to you.
Questions
- Is the Sandbox format really free?
- Yes. Download the .md file: no account, no email, no paywall. Use it for as many videos as you like.
- What do the voices cost?
- The voice comes from ElevenLabs. Its free plan is enough to try the format (about 10,000 credits a month, roughly one per character of script). Posting videos that promote anything needs a paid plan for the commercial licence, from $6 a month.
- Does it work with Codex too?
- Yes. It's a standard SKILL.md, the skill format Claude Code and Codex both read, and Morphy has it built in. Any other agent that can run code can follow it if you attach the file.
- Do I have to label the video as AI?
- On Instagram, a reel narrated by a realistic AI voice needs Meta's AI info label; switch it on when you post. On YouTube and TikTok, check the AI disclosure setting when the content looks realistic.
