📦 nf3

This plugin traces and copies only the node_modules that are actually required at runtime for your built output — powered by @vercel/nft.

Bundling external dependencies can sometimes fail or cause issues, especially when modules rely on relative paths, native bindings, or dynamic imports.

To solve this, the plugin analyzes your build output, traces its runtime dependencies, and copies a tree-shaken, deduplicated, and runtime-only subset of node_modules into dist/node_modules. The result is a minimal, self-contained distribution directory that just works.

Originally extracted from Nitro and used for optimizing nf3 package dist itself!

Usage

Rollup/Rolldown plugin

import { rollupNodeFileTrace } from "nf3";

export default {
  plugins: [
    rollupNodeFileTrace({
      // rootDir: process.cwd(),
      // outDir: "dist",
      // exportConditions: ["node", "import", "default"],
      // traceAlias: {},
      // chmod: true, // or 0o755
      // noTrace: false,
      // inline: [/^@my-scope\//],
      // external: ["fsevents"],
      // moduleDirectories: ["node_modules"],
      // traceInclude: ["some-lib"],
      // writePackageJson: true,
      // hooks: {},
      // traceOptions: { /* see https://github.com/vercel/nft#options */ }
    }),
  ],
};

API

import { traceNodeModules } from "nf3";

await traceNodeModules(["./index.mjs"], {
  /* options */
});

Hooks

After the Rollup plugin traces the required files, traceNodeModules processes them into an optimized node_modules output.

Each phase can be extended through hooks:

rollupNodeFileTrace({
  hooks: {
    traceStart: (files) => {},
    traceResult: (result) => {},
    tracedFiles: (files) => {},
    tracedPackages: (packages) => {},
  },
});

Transforming

Before writing files, you can transform some of them.

Example:

import { minify } from "oxc-minify";

rollupNodeFileTrace({
  transform: [
    {
      filter: (id) => /\.[mc]?js$/.test(id),
      handler: (code, id) => minify(id, code, {}).code,
    },
  ],
});

Development

• Clone this repository
• Install latest LTS version of Node.js
• Enable Corepack using corepack enable
• Install dependencies using pnpm install
• Run interactive tests using pnpm dev

License

Published under the MIT license.