AI Usage

Generate and run JavaScript metaframes using AI — from chat interfaces or directly from the terminal.

From Claude Code (terminal)

Two ways to use it — paste the URL for one-off use, or install the slash command for repeat use.

One-off: paste the URL

Paste the URL and describe what you want:

https://js.mtfm.io/llms-claude-code.txt

Make a bouncing ball animation

Install the /js slash command

For repeat use, install the slash command globally:

mkdir -p ~/.claude/commands
curl -sL https://js.mtfm.io/llms-claude-code.txt -o ~/.claude/commands/js.md

Then from any Claude Code session:

/js make a bouncing ball animation

How it works

Claude Code will:

1. Encode the JavaScript in memory using Buffer.from(encodeURIComponent(code)).toString('base64')
2. Open https://js.mtfm.io/#?js={encoded}&edit=true in your browser

No files are written — everything happens in a single node -e command. The &edit=true parameter opens the editor so you can modify the code. Every update opens a new tab with the latest code.

From the editor

1. Click the copy button to copy the AI prompt
2. Paste into Claude, ChatGPT, or any LLM
3. Describe what you want
4. Copy the generated JavaScript back into the editor

From an AI chat (API)

Give the LLM the URL https://js.mtfm.io/llms.txt along with your request. The LLM will respond with a JavaScript code block that you can paste into the editor at js.mtfm.io.

URL encoding format

The JavaScript is encoded into the URL hash using this scheme:

encodeURIComponent(code) → base64 → URL hash parameter

In JavaScript:

const encoded = btoa(encodeURIComponent(code));
const url = `https://js.mtfm.io/#?js=${encoded}`;

LLM integration files

File	Purpose
/llms.txt	For AI chat / API — outputs a JavaScript code block
/llms-claude-code.txt	For Claude Code terminal — encodes and opens browser directly

Both files contain the same JavaScript coding guidance (ES6 modules, globals, patterns, available libraries). They differ only in how the output is delivered.