README.md

"use prompt"

use-prompt-demo.mp4

Add compile-time GenAI to any SWC-powered project!

function CoolButton() {
  "use prompt: a button that changes its background color when clicked";
}

export default function Home() {
  return <CoolButton />;
}

Try it out for yourself!

Installation

1. Add the package as a dependency:

   $ pnpm add swc-plugin-use-prompt

2. Add the plugin to your next.config.{ts,js} or .swcrc

   // next.config.js
   const nextConfig = {
     experimental: {
       swcPlugins: [["swc-plugin-use-prompt", {}]],
     },
   };

   or

   // .swcrc
   {
     "jsc": {
       "experimental": {
         "plugins": [["swc-plugin-use-prompt", {}]],
       },
     },
   }

3. Run pnpm use-prompt alongside your regular build step!

   By default, this will watch your app and src directories for JS and TS files, but you can change this using the -p option.

Check out the Next.js example to see it in action.

Motivation

Inspired by the new "use cache" directive and relentless improvements in generative AI, this project's existence felt necessary.

How It Works

Generation happens in two passes: the CLI script and the SWC plugin.

The use-prompt CLI script uses @swc/core to parse through source code and identify all "use prompt:" directives. It extracts the prompts and calls OpenAI's API to generate code snippets, which are then saved in a cache file.

At compile time, the SWC plugin reads from this cache file and modifies the AST to insert the generated code before compilation is complete. There is some additional complexity around dealing with package import naming clashes, which is handled by substituting unique names for all imports required by a generated function / component.

Ideally, codegen would happen in a single pass. However, the SWC plugin runs in a WASM/WASI sandbox that doesn't have access to the network, so it's not possible to call remote APIs directly. This may be changed in the future though, since the SWC plugin API is very experimental.