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What is the package.json "exports" field and conditional exports?

Q: What is the package.json "exports" field and conditional exports?

**TL;DR.** The "exports" field defines a package's **official public entry points** and **hides everything else** — consumers can no longer deep-import internal files. **Conditional exports** ( import , require , types , node , default ) resolve **different files per environment**, which is how a package ships dual ESM/CJS builds and types. import 'pkg' exports map <rect class='d-box'

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Controlling a package's public entry points and per-environment resolution.

nodejsesmpackagingexports

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Dual ESM/CJS package with types

{
  "name": "pkg",
  "exports": {
    ".": {
      "types":   "./dist/index.d.ts",
      "import":  "./dist/index.mjs",
      "require": "./dist/index.cjs",
      "default": "./dist/index.mjs"
    },
    "./package.json": "./package.json"
  }
}
// require('pkg/src/secret.js') now fails — internals are hidden.

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