Install

ParaScript is a parse-time syntax extension over TypeScript. To use it outside of Parabun, you need three things:

1. A transpiler that recognizes .pts files. Today this is bun build — Bun’s parser is what implements the syntax.
2. A bundler alias that maps para:* import specifiers to the runtime shim package. One line of bundler config.
3. The runtime package, parabun-browser-shims.

A standalone @parascript/transpile npm package (no Bun required) is on the roadmap. Until it ships, the build host needs Bun installed; runtime hosts (browser, Lambda, Workers, Node, Deno) do not.

1. Install Bun on the build host

curl -fsSL https://bun.sh/install | bash

2. Install the runtime package

npm install parabun-browser-shims

parabun-browser-shims is pure JavaScript with no native dependencies. It exports the runtime side of every para:* module the language uses: signals, arena, parallel, pipeline, simd, arrow, csv.

3. Configure your bundler

Vite

vite.config.ts

import { defineConfig } from "vite";

export default defineConfig({
  resolve: {
    alias: [{ find: /^para:(.*)$/, replacement: "parabun-browser-shims/$1" }],
  },
});

esbuild

import { build } from "esbuild";

await build({
  entryPoints: ["src/main.js"],
  bundle: true,
  outfile: "dist/main.js",
  plugins: [{
    name: "para-alias",
    setup(b) {
      b.onResolve({ filter: /^para:/ }, args => ({
        path: require.resolve(`parabun-browser-shims/${args.path.slice(5)}`),
      }));
    },
  }],
});

webpack

webpack.config.js

module.exports = {
  resolve: {
    alias: {
      "para:signals":  "parabun-browser-shims/signals",
      "para:arena":    "parabun-browser-shims/arena",
      "para:parallel": "parabun-browser-shims/parallel",
      "para:pipeline": "parabun-browser-shims/pipeline",
      "para:simd":     "parabun-browser-shims/simd",
      "para:arrow":    "parabun-browser-shims/arrow",
      "para:csv":      "parabun-browser-shims/csv",
    },
  },
};

4. Build

bun build src/main.pts --outdir dist/

The output is standard JavaScript. Bundle it with your normal toolchain (vite build, webpack, etc.); the alias takes care of the para:* imports.

Editor extension

A VS Code-family extension provides the .pts / .ptsx / .pjs / .pjsx TextMate grammar and an LSP with hover, go-to-definition, semantic highlighting, purity diagnostics, and operator documentation.

curl -fsSL https://raw.githubusercontent.com/airgap/parabun/main/install-extension.sh | bash

The script installs into any of code, cursor, or kiro it finds on $PATH.

Platform notes

The build step (Bun + bundler) runs on Linux, macOS, and Windows. The output is standard JavaScript; runtime targets are anywhere a JavaScript engine runs. The shim package targets ES2022.