📦️ @packlet/build

@packlet/build is a focused, minimal build layer for TypeScript and JavaScript packages. It wraps Bun’s high-performance bundler with a clean, consistent interface tailored for libraries and CLIs—no heavy configuration, no multi-tool orchestration.

If you want a predictable, modern build pipeline with ESM-first output, optional CJS, and automatic type generation, @packlet/build gives you exactly that with a single command or function call.

Use it standalone or as the build engine behind the higher-level packlet CLI.

Features

• ESM by default (dist/index.mjs), with optional CJS output (dist/index.cjs)
• TypeScript declarations generated automatically into dist/
• Fast Bun-based bundling with a single consistent interface
• Simple control over sourcemaps, minification, externalization, and CLI executables
• Programmatic API for embedding in your own tooling

Installation

# with bun
bun add -D @packlet/build

# with npm
npm install -D @packlet/build

Note: @packlet/build uses bun build internally. Bun must be installed on the machine running the build (recommended: Bun ≥ 1.2.0). For environments without Bun, you may still use the programmatic API with custom bundlers.

Usage via npm scripts

Add build scripts to your package.json:

{
  "scripts": {
    "build": "packlet-build build --sourcemap none --external-auto",
    "build:cli": "packlet-build build --cjs --exec-js --sourcemap none --external-auto"
  }
}

Run them normally:

npm run build
# or
bun run build

Or run the CLI directly using npx / bunx:

npx @packlet/build build --sourcemap none --external-auto

Programmatic API

You can also invoke the builder directly from JavaScript or TypeScript for full control:

import { build } from "@packlet/build"

await build({
  entry: "src/index.ts",
  outdir: "dist",
  formats: ["esm"],
  sourcemap: "none",
  types: true,
  target: "node",
  execJs: false,
  minify: true
})

This API is ideal for custom workflows, monorepos, or script-driven build pipelines.

CLI flags

packlet-build supports the following build flags:

• --entry <file>: entry file (default: src/index.ts)
• --outdir <dir>: output directory (default: dist)
• --formats <list>: comma-separated formats (default: esm)
• --cjs: shorthand to also emit CommonJS (index.cjs)
• --sourcemap <kind>: external or none (default: none)
• --no-types: skip type declaration generation
• --target <target>: build target (default: node)
• --exec-js: mark generated output as executable (helpful for CLIs)
• --no-minify: disable minification (enabled by default)
• --external <packages>: specify external packages
• --external-auto: automatically externalize dependencies and peerDependencies

Notes

• Type declarations come from tsc --emitDeclarationOnly, always using your local tsconfig.json.
• For debugging, prefer --sourcemap external to keep maps separate from published artifacts.
• Disable minification (--no-minify) when inspecting bundles locally.

License

MIT © KazViz