📦 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

API

import { traceNodeModules } from "nf3";

await traceNodeModules(["./index.mjs"], {
  //   outDir: "dist",
  // chmod: 0o755,
  // writePackageJson: true,
  // traceAlias: {},
  // hooks: {},
  // nft: {}, // https://github.com/vercel/nft#options
});

Rollup/Rolldown/Vite Plugin

import { externals } from "nf3/plugin";

export default {
  plugins: [
    externals({
      // rootDir: ".",
      // conditions: ["node", "import", "default"],
      // include: [/^@my-scope\//],
      // exclude: ["fsevents"],
      // traceInclude: ["some-lib"],
      // trace: {}
    }),
  ],
};

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,
    },
  ],
});

Packages DB

NF3 exports a list of known packages that include native code and require platform-specific builds.

These packages cannot be bundled and should be traced as external dependencies most of the time and often need tracing.

import { NodeNativePackages } from "nf3/db";

NF3 also exports a list of packages that must be externalized rather than bundled, due to bundler compatibility issues with their module format or dynamic imports.

import { NonBundleablePackages } from "nf3/db";

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.