vercel-labs

Fx0 — Design skill for Claude Code

Design community

A lightweight design agent built with libfx.

How to install Fx0

This entry records only its repository, not the path inside it, so there is no exact command to give. Open vercel-labs/fx0 and copy the folder into ~/.claude/skills/, or the file into ~/.claude/agents/.

What Fx0 does

A lightweight design agent built with libfx. Describe a page and an agent writes it as one HTML file.

Alternatives in Design

Remix — Restyle a site in another design vocabulary — brutalist, swiss, art-deco, cyberpunk, soft-ui, or editorial 3.6k ★
Clui Cc — A lightweight, transparent desktop overlay for Claude Code on macOS 956 ★
Scaffold Project — Scaffold a new design-product project that matches the recommended Claude Code layout (the reference structure 781 ★

README

fx0

fx0 is an open-source, lightweight design agent built with [libfx](https://www.npmjs.com/package/libfx). You describe a page and an agent writes it as one HTML file.

fx0 is also a working example of an app built on libfx. [One `createFxAgent()` call](#durability) gives it the agent loop, streaming, tool calls, retries and durable sessions, and `createFxEngine()` runs each subagent.

Try it at [fx0.vercel.dev](https://fx0.vercel.dev), or clone it and make it your own.

Features

Sign in with Vercel to bill model calls through AI Gateway to your own team.
Optionally offer five free Opus 5.5 Fast prompts per IP without sign-in or a card. BotID protects the trial; a server-only Gateway key funds its admitted prompts.
A chat survives the function dying mid-reply: the turn continues where it stopped. See Durability.
Every turn keeps its version of the design. You can reopen any of them and copy or download the HTML.
Pick each chat's model, with its reasoning effort and fast mode. New chats start on fast Claude Opus 5.5, or on FX0_MODEL when it's set.
The agent can search the web and fetch pages for reference.
Start from one of ten design.md styles, or upload your own. The ten styles, and the one-line descriptions in the picker, come from VoltAgent's awesome-design-md, which you can browse at getdesign.md. Thanks to VoltAgent for publishing them.
Type a message before you sign in. The draft, images included, waits in the tab for 15 minutes while you sign in.
A turn stops after 64 model steps, its subagents' included, which keeps an agent stuck in a loop from running up a bill.
In paid-only chats, a text message sent while the agent works steers it, as in the fx CLI. Trial chats run each input as its own turn so free and paid funding stay separate.