spool is a local-first prototyping canvas for websites, apps and presentations. Your agent writes live TSX frames into your repo, and you play the flows between them like a real app.
Free and open source on your Mac. Spool Cloud for teams, from $16 a seat →
Claude Code in a terminal, Claude, Codex or the Agent tab inside spool. Each writes TSX into design/, and the canvas draws each file as it is saved.
A link is one line in the frame, so Fair answers like the app it will become. Tap Saturday and the day opens, because fair-now says where that row goes.
design/frames/app/fair-now/frame.tsx
Each slide is a frame at 1280 × 720 and the deck is the flow between them. Present it from spool and the ring moves with you from slide to slide.
Three.js, WebGL and WebGPU work in a frame like any other React. Stilla's speaker is a real model: pick a colour and it changes, go on to the top and the camera follows.
With Spool Cloud, every save reaches the team in about a second, and you see each teammate on the canvas by name.
14 days free, no card. Then $20 a seat a month, or $16 billed yearly. Admins and editors are seats; viewers are free.
Every save in a team project reaches everyone's copy as real files in their own repo.
See who is on which page, and watch a teammate click through a live frame as they do it.
Send a protected link to a flow. A client opens it in the browser and plays it.
Your team's projects open in any browser, view only, with the same canvas and the same player.
The Mac app keeps itself up to date. The npm package runs the same canvas from your terminal on any machine with Node 22.
spool is open source under the MIT license. Read the code on GitHub.