Bundler & Dev Server

PledgePack

An incremental bundler and dev server written in Rust and Zig, built into PledgeJS. Oxc for transforms, Lightning CSS for styles, Axum for the dev server, and a Zig C ABI for hot-path file I/O and SIMD scanning.

View on GitHub npm package

Why PledgePack?

PledgePack is the default bundler in PledgeJS — no configuration needed. It replaces Vite, webpack, and Rollup with a single native toolchain.

Unified Graph

A single, unified module graph for client, server, and edge environments — no stitching multiple compiler bundles together.

Incremental Computation

Work is parallelized across cores and cached down to the function level. Once a piece of work is done, PledgePack never repeats it. Results persist to disk between runs.

Lazy Bundling

PledgePack only bundles what the dev server actually requests, cutting initial compile times and memory usage for large apps.

Native Hot Paths

A Zig C ABI handles file I/O, module graph traversal, SIMD source scanning, and memory-mapped reads — zero-cost FFI into the Rust orchestrator.

Supported platforms

PledgePack ships platform-specific native bindings. On platforms without native bindings, PledgeJS falls back to WebAssembly for core Oxc features (compilation, minification) — but PledgePack itself requires native bindings.

Platform	Architecture
macOS (Darwin)	x64, ARM64
Windows	x64, ARM64
Linux (glibc)	x64, ARM64
Linux (musl)	x64, ARM64

Getting started

PledgePack is the default bundler in PledgeJS. No configuration is needed — just run the CLI.

package.json

{
  "scripts": {
    "dev": "pledgepack dev",
    "build": "pledgepack build",
    "serve": "pledgepack serve"
  }
}

Install globally or as a dev dependency:

npm install -g pledgepack
# or
npm install --save-dev pledgepack

Supported features

Zero-configuration for the common use cases. Below is a summary of what is supported out of the box.

Language features

Feature	Status	Notes
JavaScript & TypeScript	Supported	Oxc under the hood. Type-checking is not done by PledgePack (run tsc --watch or rely on your IDE).
ECMAScript (ESNext)	Supported	Latest ECMAScript features, matching Oxc's coverage.
CommonJS	Supported	require() syntax handled out of the box.
ESM	Supported	Static and dynamic import fully supported.

Framework and React features

Feature	Status	Notes
JSX / TSX	Supported	Oxc handles JSX/TSX compilation.
Fast Refresh	Supported	React component state preservation via the React adapter.
React Server Components (RSC)	Supported	Correct server/client bundling via the Next.js and PledgeJS adapters.
Solid JSX	Supported	Automatic JSX runtime with solid-js via the Solid adapter.
Vue SFC	Transform	.vue Single-File Components, scoped CSS, script setup.
Svelte SFC	Transform	.svelte SFCs, scoped CSS, render functions.
Astro	Transform	.astro frontmatter, islands-ready.

CSS and styling

Feature	Status	Notes
Global CSS	Supported	Import .css files directly.
CSS Modules	Supported	.module.css scoped class names with blake3 content hashing.
CSS Nesting	Supported	Modern CSS nesting via Lightning CSS.
@import syntax	Supported	Combine multiple CSS files.
PostCSS / Tailwind	Supported	@tailwind directives, @apply expansion, base reset, utility classes.
Sass / SCSS	Supported	Compilation via the grass crate (pure Rust).

CLI reference

The CLI command is pledge (alias: pledgepack).

Command	Description
pledgepack dev	Start the dev server with HMR on port 3000.
pledgepack dev --port 8080	Custom port.
pledgepack dev --https	HTTPS with self-signed certs via rustls.
pledgepack build	Production build to dist/.
pledgepack build --watch	Watch mode rebuilds.
pledgepack build --profile	Per-phase timing (parse, transform, optimize, emit).
pledgepack build --type-check	TypeScript type checking.
pledgepack build --check-budgets	Bundle size budgets.
pledgepack serve	Serve the production build on port 4000.
pledgepack preview	Alias for serve.
pledgepack create react my-app	Scaffold a React app.
pledgepack create pledgejs my-app	Scaffold a PledgeJS app (default).
pledgepack test	Run tests with a Vitest-compatible API.
pledgepack bench	Benchmark build performance.
pledgepack analyze --graph	Bundle analyzer with dependency graph.
pledgepack cache clear	Clear the disk cache.
pledgepack doctor	Diagnose build issues.
pledgepack migrate	Migrate from Vite / webpack / CRA.

Configuration

Configure PledgePack via pledge.config.ts. Resolution order: pledge.config.ts → .js → .mjs → pledge.json → defaults.

pledge.config.ts

// pledge.config.ts
export default {
  appDir: 'app',
  framework: 'react',
  sourceMaps: true,
  envPrefix: 'PLEDGE_',
  envDts: true,
  htmlEntry: 'index.html',
  compressGzip: true,
  compressBrotli: true,
  edgeTarget: 'cloudflare',
  plugins: ['./plugins/my-plugin.ts'],
  image: { quality: 80, webp: true, maxWidth: 1920, maxHeight: 1080 },
  library: { entry: 'src/index.ts', formats: ['esm', 'cjs'], name: 'MyLib', external: ['react'], declarations: true },
  https: { cert: './cert.pem', key: './key.pem' },
  serverEntry: 'server/index.ts',
  nodePolyfills: true,
  define: { 'process.env.NODE_ID': '"production"', '__VERSION__': '"1.0.0"' },
  watch: { enabled: false, debounceMs: 300 },
  devServer: {
    port: 3000,
    host: 'localhost',
    hmr: true,
    open: false,
    proxy: [{ path: '/api', target: 'http://localhost:8080', rewrite: true, ws: true }],
  },
  test: {
    include: ['**/*.{test,spec}.{ts,tsx,js,jsx}'],
    exclude: ['node_modules', '.pledge', 'dist'],
    environment: 'node',
    isolation: 'file',
    coverage: false,
    snapshot: true,
    snapshotDir: '__snapshots__',
  },
};

Environment variables are injected via import.meta.env.*. Built-in variables: PLEDGE_DEV, PLEDGE_PROD, PLEDGE_MODE, MODE, DEV, PROD, SSR.

Rust crates

PledgePack is a Rust workspace. Use the crates programmatically for integrations — the npm package is a binary launcher and does not export JS functions.

pledgepack-core

Engine, config, transform pipeline, HTML, compression, analyzer.

pledgepack-cache

Function-level incremental cache (memory + disk/bincode).

pledgepack-resolver

Module resolution (node_modules, tsconfig, exports).

pledgepack-dev-server

Dev server + HMR + CSS HMR + error overlay + proxy.

pledgepack-optimizer

Tree shaking, code splitting, vendor/shared chunks.

pledgepack-js-plugin-host

Vite-compatible JS plugin API (QuickJS via rquickjs).

pledgepack-wasm-plugin-host

WebAssembly plugin host.

pledgepack-adapter-react

React JSX + Fast Refresh adapter (Oxc-based).

pledgepack-adapter-solid

Solid.js JSX adapter (Oxc-based).

pledgepack-adapter-next

Next.js adapter (App/Pages Router, SSR, API routes).

pledgepack-adapter-tanstack

TanStack Router adapter (file-based routing).

pledgepack-adapter-pledgejs

PledgeJS adapter (React + Rust backend).

pledgepack-task-system

Parallel task execution engine.

Build with PledgePack

Native-grade performance, incremental caching, and a Vite-compatible plugin API — all from a single Rust + Zig toolchain.

Get Started GitHub repository

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