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dotenv - npm Package Compare versions

Comparing version
17.2.4
 to
17.3.0
+11
-1
CHANGELOG.md

@@ -5,4 +5,14 @@ # Changelog

## [Unreleased](https://github.com/motdotla/dotenv/compare/v17.2.4...master)
## [Unreleased](https://github.com/motdotla/dotenv/compare/v17.3.0...master)
## [17.3.0](https://github.com/motdotla/dotenv/compare/v17.2.4...v17.3.0) (2026-02-12)
### Added
* Add a new README section on dotenv’s approach to the agentic future.
### Changed
* Rewrite README to get humans started more quickly with less noise while simultaneously making more accessible for llms and agents to go deeper into details.
## [17.2.4](https://github.com/motdotla/dotenv/compare/v17.2.3...v17.2.4) (2026-02-05)

@@ -9,0 +19,0 @@ 

+3
-6
lib/main.js

@@ -14,8 +14,5 @@ const fs = require('fs')

'🔐 prevent building .env in docker: https://dotenvx.com/prebuild',
'📡 add observability to secrets: https://dotenvx.com/ops',
'👥 sync secrets across teammates & machines: https://dotenvx.com/ops',
'🗂️ backup and recover secrets: https://dotenvx.com/ops',
'✅ audit secrets and track compliance: https://dotenvx.com/ops',
'🔄 add secrets lifecycle management: https://dotenvx.com/ops',
'🔑 add access controls to secrets: https://dotenvx.com/ops',
'🤖 agentic secret storage: https://dotenvx.com/as2',
'⚡️ secrets for agents: https://dotenvx.com/as2',
'🛡️ auth for agents: https://vestauth.com',
'🛠️ run anywhere with `dotenvx run -- yourcommand`',

@@ -22,0 +19,0 @@ '⚙️ specify custom .env file path with { path: \'/custom/path/.env\' }',

+1
-1
package.json
{
"name": "dotenv",
"version": "17.2.4",
"version": "17.3.0",
"description": "Loads environment variables from .env file",

@@ -5,0 +5,0 @@ "main": "lib/main.js",

+390
-293
README.md

@@ -1,9 +0,3 @@

<div align="center">
🎉 new announcement <em><a href="https://github.com/vestauth/vestauth">vestauth: auth for agents</a></em>–from the creator of <a href="https://github.com/motdotla/dotenv"><code>dotenv</code></a> and <a href="https://github.com/dotenvx/dotenvx"><code>dotenvx</code></a>.
</div>
# dotenv [![NPM version](https://img.shields.io/npm/v/dotenv.svg?style=flat-square)](https://www.npmjs.com/package/dotenv) [![downloads](https://img.shields.io/npm/dw/dotenv)](https://www.npmjs.com/package/dotenv)
&nbsp;
# dotenv [![NPM version](https://img.shields.io/npm/v/dotenv.svg?style=flat-square)](https://www.npmjs.com/package/dotenv)
<img src="https://raw.githubusercontent.com/motdotla/dotenv/master/dotenv.svg" alt="dotenv" align="right" width="200" />

@@ -13,43 +7,18 @@

[![js-standard-style](https://img.shields.io/badge/code%20style-standard-brightgreen.svg?style=flat-square)](https://github.com/feross/standard)
[![LICENSE](https://img.shields.io/github/license/motdotla/dotenv.svg)](LICENSE)
[![codecov](https://codecov.io/gh/motdotla/dotenv-expand/graph/badge.svg?token=pawWEyaMfg)](https://codecov.io/gh/motdotla/dotenv-expand)
[Watch the tutorial](https://www.youtube.com/watch?v=YtkZR0NFd1g)
* [🌱 Install](#-install)
* [🏗️ Usage (.env)](#%EF%B8%8F-usage)
* [🌴 Multiple Environments 🆕](#-manage-multiple-environments)
* [🚀 Deploying (encryption) 🆕](#-deploying)
* [📚 Examples](#-examples)
* [📖 Docs](#-documentation)
* [❓ FAQ](#-faq)
* [⏱️ Changelog](./CHANGELOG.md)
&nbsp;
## 🌱 Install
## Usage
```bash
Install it.
```sh
npm install dotenv --save
```
You can also use an npm-compatible package manager like yarn, bun or pnpm:
Create a `.env` file in the root of your project:
```bash
yarn add dotenv
```
```bash
bun add dotenv
```
```bash
pnpm add dotenv
```
## 🏗️ Usage
<a href="https://www.youtube.com/watch?v=YtkZR0NFd1g">
<img src="https://img.youtube.com/vi/YtkZR0NFd1g/hqdefault.jpg" alt="how to use dotenv video tutorial" align="right" width="330" />
<img src="https://simpleicons.vercel.app/youtube/ff0000" alt="youtube/@dotenvorg" align="right" width="24" />
</a>
Create a `.env` file in the root of your project (if using a monorepo structure like `apps/backend/app.js`, put it in the root of the folder where your `app.js` process runs):
```dosini
```ini
# .env
S3_BUCKET="YOURS3BUCKET"

@@ -59,11 +28,20 @@ SECRET_KEY="YOURSECRETKEYGOESHERE"

As early as possible in your application, import and configure dotenv:
And as early as possible in your application, import and configure dotenv:
```javascript
require('dotenv').config()
require('dotenv').config() // or import 'dotenv/config' if you're using ES6
...
console.log(process.env) // remove this after you've confirmed it is working
```
.. [or using ES6?](#how-do-i-use-dotenv-with-import)
That's it. `process.env` now has the keys and values you defined in your `.env` file:
&nbsp;
## Advanced
<details><summary>ES6</summary><br>
Import with [ES6](#how-do-i-use-dotenv-with-import):
```javascript

@@ -77,22 +55,43 @@ import 'dotenv/config'

import dotenv from 'dotenv'
dotenv.config({ path: '/custom/path/to/.env' })
```
That's it. `process.env` now has the keys and values you defined in your `.env` file:
</details>
<details><summary>bun</summary><br>
```javascript
require('dotenv').config()
// or import 'dotenv/config' if you're using ES6
```sh
bun add dotenv
```
...
</details>
<details><summary>yarn</summary><br>
s3.getBucketCors({Bucket: process.env.S3_BUCKET}, function(err, data) {})
```sh
yarn add dotenv
```
### Multiline values
</details>
<details><summary>pnpm</summary><br>
```sh
pnpm add dotenv
```
</details>
<details><summary>Monorepos</summary><br>
For monorepos with a structure like `apps/backend/app.js`, put it the `.env` file in the root of the folder where your `app.js` process runs.
```ini
# app/backend/.env
S3_BUCKET="YOURS3BUCKET"
SECRET_KEY="YOURSECRETKEYGOESHERE"
```
</details>
<details><summary>Multiline Values</summary><br>
If you need multiline variables, for example private keys, those are now supported (`>= v15.0.0`) with line breaks:
```dosini
```ini
PRIVATE_KEY="-----BEGIN RSA PRIVATE KEY-----

@@ -107,11 +106,12 @@ ...

```dosini
```ini
PRIVATE_KEY="-----BEGIN RSA PRIVATE KEY-----\nKh9NV...\n-----END RSA PRIVATE KEY-----\n"
```
### Comments
</details>
<details><summary>Comments</summary><br>
Comments may be added to your file on their own line or inline:
```dosini
```ini
# This is a comment

@@ -124,3 +124,4 @@ SECRET_KEY=YOURSECRETKEYGOESHERE # comment

### Parsing
</details>
<details><summary>Parsing</summary><br>

@@ -136,7 +137,8 @@ The engine which parses the contents of your file containing environment variables is available to use. It accepts a String or Buffer and will return an Object with the parsed keys and values.

### Preload
</details>
<details><summary>Preload</summary><br>
> Note: Consider using [`dotenvx`](https://github.com/dotenvx/dotenvx) instead of preloading. I am now doing (and recommending) so.
>
> It serves the same purpose (you do not need to require and load dotenv), adds better debugging, and works with ANY language, framework, or platform. – [motdotla](https://github.com/motdotla)
> It serves the same purpose (you do not need to require and load dotenv), adds better debugging, and works with ANY language, framework, or platform. – [motdotla](https://mot.la)

@@ -165,5 +167,6 @@ You can use the `--require` (`-r`) [command line option](https://nodejs.org/api/cli.html#-r---require-module) to preload dotenv. By doing this, you do not need to require and load dotenv in your application code.

### Variable Expansion
</details>
<details><summary>Variable Expansion</summary><br>
Use [dotenvx](https://github.com/dotenvx/dotenvx) to use variable expansion.
Use [dotenvx](https://github.com/dotenvx/dotenvx) for variable expansion.

@@ -187,5 +190,6 @@ Reference and expand variables already on your machine for use in your .env file.

### Command Substitution
</details>
<details><summary>Command Substitution</summary><br>
Use [dotenvx](https://github.com/dotenvx/dotenvx) to use command substitution.
Use [dotenvx](https://github.com/dotenvx/dotenvx) for command substitution.

@@ -208,19 +212,26 @@ Add the output of a command to one of your variables in your .env file.

### Syncing
</details>
<details><summary>Encryption</summary><br>
You need to keep `.env` files in sync between machines, environments, or team members? Use [dotenvx](https://github.com/dotenvx/dotenvx) to encrypt your `.env` files and safely include them in source control. This still subscribes to the twelve-factor app rules by generating a decryption key separate from code.
Use [dotenvx](https://github.com/dotenvx/dotenvx) for encryption.
### Multiple Environments
Add encryption to your `.env` files with a single command.
Use [dotenvx](https://github.com/dotenvx/dotenvx) to generate `.env.ci`, `.env.production` files, and more.
```
$ dotenvx set HELLO Production -f .env.production
$ echo "console.log('Hello ' + process.env.HELLO)" > index.js
### Deploying
$ DOTENV_PRIVATE_KEY_PRODUCTION="<.env.production private key>" dotenvx run -- node index.js
[dotenvx] injecting env (2) from .env.production
Hello Production
```
You need to deploy your secrets in a cloud-agnostic manner? Use [dotenvx](https://github.com/dotenvx/dotenvx) to generate a private decryption key that is set on your production server.
[learn more](https://github.com/dotenvx/dotenvx?tab=readme-ov-file#encryption)
## 🌴 Manage Multiple Environments
</details>
<details><summary>Multiple Environments</summary><br>
Use [dotenvx](https://github.com/dotenvx/dotenvx)
Use [dotenvx](https://github.com/dotenvx/dotenvx) to manage multiple environments.
Run any environment locally. Create a `.env.ENVIRONMENT` file and use `--env-file` to load it. It's straightforward, yet flexible.
Run any environment locally. Create a `.env.ENVIRONMENT` file and use `-f` to load it. It's straightforward, yet flexible.

@@ -231,3 +242,3 @@ ```bash

$ dotenvx run --env-file=.env.production -- node index.js
$ dotenvx run -f=.env.production -- node index.js
Hello production

@@ -244,3 +255,3 @@ > ^^

$ dotenvx run --env-file=.env.local --env-file=.env -- node index.js
$ dotenvx run -f=.env.local -f=.env -- node index.js
Hello local

@@ -251,21 +262,47 @@ ```

## 🚀 Deploying
</details>
<details><summary>Production</summary><br>
Use [dotenvx](https://github.com/dotenvx/dotenvx).
Use [dotenvx](https://github.com/dotenvx/dotenvx) for production deploys.
Add encryption to your `.env` files with a single command. Pass the `--encrypt` flag.
Create a `.env.production` file.
```sh
$ echo "HELLO=production" > .env.production
```
$ dotenvx set HELLO Production --encrypt -f .env.production
$ echo "console.log('Hello ' + process.env.HELLO)" > index.js
$ DOTENV_PRIVATE_KEY_PRODUCTION="<.env.production private key>" dotenvx run -- node index.js
[dotenvx] injecting env (2) from .env.production
Hello Production
Encrypt it.
```sh
$ dotenvx encrypt -f .env.production
```
[learn more](https://github.com/dotenvx/dotenvx?tab=readme-ov-file#encryption)
Set `DOTENV_PRIVATE_KEY_PRODUCTION` (found in `.env.keys`) on your server.
## 📚 Examples
```
$ heroku config:set DOTENV_PRIVATE_KEY_PRODUCTION=value
```
Commit your `.env.production` file to code and deploy.
```
$ git add .env.production
$ git commit -m "encrypted .env.production"
$ git push heroku main
```
Dotenvx will decrypt and inject the secrets at runtime using `dotenvx run -- node index.js`.
</details>
<details><summary>Syncing</summary><br>
Use [dotenvx](https://github.com/dotenvx/dotenvx) to sync your .env files.
Encrypt them with `dotenvx encrypt -f .env` and safely include them in source control. Your secrets are securely synced with your git.
This still subscribes to the twelve-factor app rules by generating a decryption key separate from code.
</details>
<details><summary>More Examples</summary><br>
See [examples](https://github.com/dotenv-org/examples) of using dotenv with various frameworks, languages, and configurations.

@@ -290,4 +327,268 @@

## 📖 Documentation
</details>
&nbsp;
## Agents
<img src="https://dotenvx.com/assets/img/as2/9.jpg" height="400" alt="dotenvx-as2" align="right"/>
> Software is changing, and dotenv must change with it—that is why I built [agentic secret stoarge (AS2)](https://dotenvx.com/as2). Agents run code without humans at terminals, so plaintext `.env` files are the wrong primitive.
>
> AS2 is built for autonomous software: encrypted by default, zero console access, and cryptography‑first delivery that keeps operators out of the loop.
>
> It is backed by [Vestauth](https://github.com/vestauth/vestauth), the trusted, pioneering auth layer for agents—giving each agent a cryptographic identity so requests are signed with private keys and verified with public keys. No shared secrets to leak.
>
> It's what I'm using now. - [motdotla](https://mot.la)
### Quickstart
Install vestauth and initialize your agent.
```bash
npm i -g vestauth
vestauth agent init
```
Your agent `set`s secrets with a simple `curl` endpoint:
```bash
vestauth agent curl -X POST https://as2.dotenvx.com/set '{"KEY":"value"}'
```
And your agent `get`s secrets with a simple `curl` endpoint:
```bash
vestauth agent curl https://as2.dotenvx.com/get?key=KEY
```
That's it! This new primitive unlocks secrets access for agents without human-in-the-loop, oauth flows, or API keys. It's the future for agents.
&nbsp;
## FAQ
<details><summary>Should I commit my `.env` file?</summary><br/>
No.
Unless you encrypt it with [dotenvx](https://github.com/dotenvx/dotenvx). Then we recommend you do.
</details>
<details><summary>What about variable expansion?</summary><br/>
Use [dotenvx](https://github.com/dotenvx/dotenvx).
</details>
<details><summary>Should I have multiple `.env` files?</summary><br/>
We recommend creating one `.env` file per environment. Use `.env` for local/development, `.env.production` for production and so on. This still follows the twelve factor principles as each is attributed individually to its own environment. Avoid custom set ups that work in inheritance somehow (`.env.production` inherits values form `.env` for example). It is better to duplicate values if necessary across each `.env.environment` file.
> In a twelve-factor app, env vars are granular controls, each fully orthogonal to other env vars. They are never grouped together as “environments”, but instead are independently managed for each deploy. This is a model that scales up smoothly as the app naturally expands into more deploys over its lifetime.
>
> – [The Twelve-Factor App](http://12factor.net/config)
Additionally, we recommend using [dotenvx](https://github.com/dotenvx/dotenvx) to encrypt and manage these.
</details>
<details><summary>How do I use dotenv with `import`?</summary><br/>
Simply..
```javascript
// index.mjs (ESM)
import 'dotenv/config' // see https://github.com/motdotla/dotenv#how-do-i-use-dotenv-with-import
import express from 'express'
```
A little background..
> When you run a module containing an `import` declaration, the modules it imports are loaded first, then each module body is executed in a depth-first traversal of the dependency graph, avoiding cycles by skipping anything already executed.
>
> – [ES6 In Depth: Modules](https://hacks.mozilla.org/2015/08/es6-in-depth-modules/)
What does this mean in plain language? It means you would think the following would work but it won't.
`errorReporter.mjs`:
```js
class Client {
constructor (apiKey) {
console.log('apiKey', apiKey)
this.apiKey = apiKey
}
}
export default new Client(process.env.API_KEY)
```
`index.mjs`:
```js
// Note: this is INCORRECT and will not work
import * as dotenv from 'dotenv'
dotenv.config()
import errorReporter from './errorReporter.mjs' // process.env.API_KEY will be blank!
```
`process.env.API_KEY` will be blank.
Instead, `index.mjs` should be written as..
```js
import 'dotenv/config'
import errorReporter from './errorReporter.mjs'
```
Does that make sense? It's a bit unintuitive, but it is how importing of ES6 modules work. Here is a [working example of this pitfall](https://github.com/dotenv-org/examples/tree/master/usage/dotenv-es6-import-pitfall).
There are two alternatives to this approach:
1. Preload with dotenvx: `dotenvx run -- node index.js` (_Note: you do not need to `import` dotenv with this approach_)
2. Create a separate file that will execute `config` first as outlined in [this comment on #133](https://github.com/motdotla/dotenv/issues/133#issuecomment-255298822)
</details>
<details><summary>Can I customize/write plugins for dotenv?</summary><br/>
Yes! `dotenv.config()` returns an object representing the parsed `.env` file. This gives you everything you need to continue setting values on `process.env`. For example:
```js
const dotenv = require('dotenv')
const variableExpansion = require('dotenv-expand')
const myEnv = dotenv.config()
variableExpansion(myEnv)
```
</details>
<details><summary>What rules does the parsing engine follow?</summary><br/>
The parsing engine currently supports the following rules:
- `BASIC=basic` becomes `{BASIC: 'basic'}`
- empty lines are skipped
- lines beginning with `#` are treated as comments
- `#` marks the beginning of a comment (unless when the value is wrapped in quotes)
- empty values become empty strings (`EMPTY=` becomes `{EMPTY: ''}`)
- inner quotes are maintained (think JSON) (`JSON={"foo": "bar"}` becomes `{JSON:"{\"foo\": \"bar\"}"`)
- whitespace is removed from both ends of unquoted values (see more on [`trim`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/Trim)) (`FOO= some value ` becomes `{FOO: 'some value'}`)
- single and double quoted values are escaped (`SINGLE_QUOTE='quoted'` becomes `{SINGLE_QUOTE: "quoted"}`)
- single and double quoted values maintain whitespace from both ends (`FOO=" some value "` becomes `{FOO: ' some value '}`)
- double quoted values expand new lines (`MULTILINE="new\nline"` becomes
```
{MULTILINE: 'new
line'}
```
- backticks are supported (`` BACKTICK_KEY=`This has 'single' and "double" quotes inside of it.` ``)
</details>
<details><summary>What about syncing and securing .env files?</summary><br/>
Use [dotenvx](https://github.com/dotenvx/dotenvx) to unlock syncing encrypted .env files over git.
</details>
<details><summary>What if I accidentally commit my `.env` file to code?</summary><br/>
Remove it, [remove git history](https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/removing-sensitive-data-from-a-repository) and then install the [git pre-commit hook](https://github.com/dotenvx/dotenvx#pre-commit) to prevent this from ever happening again.
```
npm i -g @dotenvx/dotenvx
dotenvx precommit --install
```
</details>
<details><summary>What happens to environment variables that were already set?</summary><br/>
By default, we will never modify any environment variables that have already been set. In particular, if there is a variable in your `.env` file which collides with one that already exists in your environment, then that variable will be skipped.
If instead, you want to override `process.env` use the `override` option.
```javascript
require('dotenv').config({ override: true })
```
</details>
<details><summary>How can I prevent committing my `.env` file to a Docker build?</summary><br/>
Use the [docker prebuild hook](https://dotenvx.com/docs/features/prebuild).
```bash
# Dockerfile
...
RUN curl -fsS https://dotenvx.sh/ | sh
...
RUN dotenvx prebuild
CMD ["dotenvx", "run", "--", "node", "index.js"]
```
</details>
<details><summary>How come my environment variables are not showing up for React?</summary><br/>
Your React code is run in Webpack, where the `fs` module or even the `process` global itself are not accessible out-of-the-box. `process.env` can only be injected through Webpack configuration.
If you are using [`react-scripts`](https://www.npmjs.com/package/react-scripts), which is distributed through [`create-react-app`](https://create-react-app.dev/), it has dotenv built in but with a quirk. Preface your environment variables with `REACT_APP_`. See [this stack overflow](https://stackoverflow.com/questions/42182577/is-it-possible-to-use-dotenv-in-a-react-project) for more details.
If you are using other frameworks (e.g. Next.js, Gatsby...), you need to consult their documentation for how to inject environment variables into the client.
</details>
<details><summary>Why is the `.env` file not loading my environment variables successfully?</summary><br/>
Most likely your `.env` file is not in the correct place. [See this stack overflow](https://stackoverflow.com/questions/42335016/dotenv-file-is-not-loading-environment-variables).
Turn on debug mode and try again..
```js
require('dotenv').config({ debug: true })
```
You will receive a helpful error outputted to your console.
</details>
<details><summary>Why am I getting the error `Module not found: Error: Can't resolve 'crypto|os|path'`?</summary><br/>
You are using dotenv on the front-end and have not included a polyfill. Webpack < 5 used to include these for you. Do the following:
```bash
npm install node-polyfill-webpack-plugin
```
Configure your `webpack.config.js` to something like the following.
```js
require('dotenv').config()
const path = require('path');
const webpack = require('webpack')
const NodePolyfillPlugin = require('node-polyfill-webpack-plugin')
module.exports = {
mode: 'development',
entry: './src/index.ts',
output: {
filename: 'bundle.js',
path: path.resolve(__dirname, 'dist'),
},
plugins: [
new NodePolyfillPlugin(),
new webpack.DefinePlugin({
'process.env': {
HELLO: JSON.stringify(process.env.HELLO)
}
}),
]
};
```
Alternatively, just use [dotenv-webpack](https://github.com/mrsteele/dotenv-webpack) which does this and more behind the scenes for you.
</details>
&nbsp;
## Docs
Dotenv exposes four functions:

@@ -351,3 +652,3 @@

# .env
.env
HELLO=World
```

@@ -475,210 +776,4 @@

## ❓ FAQ
&nbsp;
### Why is the `.env` file not loading my environment variables successfully?
Most likely your `.env` file is not in the correct place. [See this stack overflow](https://stackoverflow.com/questions/42335016/dotenv-file-is-not-loading-environment-variables).
Turn on debug mode and try again..
```js
require('dotenv').config({ debug: true })
```
You will receive a helpful error outputted to your console.
### Should I commit my `.env` file?
No. We **strongly** recommend against committing your `.env` file to version
control. It should only include environment-specific values such as database
passwords or API keys. Your production database should have a different
password than your development database.
### Should I have multiple `.env` files?
We recommend creating one `.env` file per environment. Use `.env` for local/development, `.env.production` for production and so on. This still follows the twelve factor principles as each is attributed individually to its own environment. Avoid custom set ups that work in inheritance somehow (`.env.production` inherits values form `.env` for example). It is better to duplicate values if necessary across each `.env.environment` file.
> In a twelve-factor app, env vars are granular controls, each fully orthogonal to other env vars. They are never grouped together as “environments”, but instead are independently managed for each deploy. This is a model that scales up smoothly as the app naturally expands into more deploys over its lifetime.
>
> – [The Twelve-Factor App](http://12factor.net/config)
### What rules does the parsing engine follow?
The parsing engine currently supports the following rules:
- `BASIC=basic` becomes `{BASIC: 'basic'}`
- empty lines are skipped
- lines beginning with `#` are treated as comments
- `#` marks the beginning of a comment (unless when the value is wrapped in quotes)
- empty values become empty strings (`EMPTY=` becomes `{EMPTY: ''}`)
- inner quotes are maintained (think JSON) (`JSON={"foo": "bar"}` becomes `{JSON:"{\"foo\": \"bar\"}"`)
- whitespace is removed from both ends of unquoted values (see more on [`trim`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/Trim)) (`FOO= some value ` becomes `{FOO: 'some value'}`)
- single and double quoted values are escaped (`SINGLE_QUOTE='quoted'` becomes `{SINGLE_QUOTE: "quoted"}`)
- single and double quoted values maintain whitespace from both ends (`FOO=" some value "` becomes `{FOO: ' some value '}`)
- double quoted values expand new lines (`MULTILINE="new\nline"` becomes
```
{MULTILINE: 'new
line'}
```
- backticks are supported (`` BACKTICK_KEY=`This has 'single' and "double" quotes inside of it.` ``)
### What happens to environment variables that were already set?
By default, we will never modify any environment variables that have already been set. In particular, if there is a variable in your `.env` file which collides with one that already exists in your environment, then that variable will be skipped.
If instead, you want to override `process.env` use the `override` option.
```javascript
require('dotenv').config({ override: true })
```
### How come my environment variables are not showing up for React?
Your React code is run in Webpack, where the `fs` module or even the `process` global itself are not accessible out-of-the-box. `process.env` can only be injected through Webpack configuration.
If you are using [`react-scripts`](https://www.npmjs.com/package/react-scripts), which is distributed through [`create-react-app`](https://create-react-app.dev/), it has dotenv built in but with a quirk. Preface your environment variables with `REACT_APP_`. See [this stack overflow](https://stackoverflow.com/questions/42182577/is-it-possible-to-use-dotenv-in-a-react-project) for more details.
If you are using other frameworks (e.g. Next.js, Gatsby...), you need to consult their documentation for how to inject environment variables into the client.
### Can I customize/write plugins for dotenv?
Yes! `dotenv.config()` returns an object representing the parsed `.env` file. This gives you everything you need to continue setting values on `process.env`. For example:
```js
const dotenv = require('dotenv')
const variableExpansion = require('dotenv-expand')
const myEnv = dotenv.config()
variableExpansion(myEnv)
```
### How do I use dotenv with `import`?
Simply..
```javascript
// index.mjs (ESM)
import 'dotenv/config' // see https://github.com/motdotla/dotenv#how-do-i-use-dotenv-with-import
import express from 'express'
```
A little background..
> When you run a module containing an `import` declaration, the modules it imports are loaded first, then each module body is executed in a depth-first traversal of the dependency graph, avoiding cycles by skipping anything already executed.
>
> – [ES6 In Depth: Modules](https://hacks.mozilla.org/2015/08/es6-in-depth-modules/)
What does this mean in plain language? It means you would think the following would work but it won't.
`errorReporter.mjs`:
```js
class Client {
constructor (apiKey) {
console.log('apiKey', apiKey)
this.apiKey = apiKey
}
}
export default new Client(process.env.API_KEY)
```
`index.mjs`:
```js
// Note: this is INCORRECT and will not work
import * as dotenv from 'dotenv'
dotenv.config()
import errorReporter from './errorReporter.mjs' // process.env.API_KEY will be blank!
```
`process.env.API_KEY` will be blank.
Instead, `index.mjs` should be written as..
```js
import 'dotenv/config'
import errorReporter from './errorReporter.mjs'
```
Does that make sense? It's a bit unintuitive, but it is how importing of ES6 modules work. Here is a [working example of this pitfall](https://github.com/dotenv-org/examples/tree/master/usage/dotenv-es6-import-pitfall).
There are two alternatives to this approach:
1. Preload with dotenvx: `dotenvx run -- node index.js` (_Note: you do not need to `import` dotenv with this approach_)
2. Create a separate file that will execute `config` first as outlined in [this comment on #133](https://github.com/motdotla/dotenv/issues/133#issuecomment-255298822)
### Why am I getting the error `Module not found: Error: Can't resolve 'crypto|os|path'`?
You are using dotenv on the front-end and have not included a polyfill. Webpack < 5 used to include these for you. Do the following:
```bash
npm install node-polyfill-webpack-plugin
```
Configure your `webpack.config.js` to something like the following.
```js
require('dotenv').config()
const path = require('path');
const webpack = require('webpack')
const NodePolyfillPlugin = require('node-polyfill-webpack-plugin')
module.exports = {
mode: 'development',
entry: './src/index.ts',
output: {
filename: 'bundle.js',
path: path.resolve(__dirname, 'dist'),
},
plugins: [
new NodePolyfillPlugin(),
new webpack.DefinePlugin({
'process.env': {
HELLO: JSON.stringify(process.env.HELLO)
}
}),
]
};
```
Alternatively, just use [dotenv-webpack](https://github.com/mrsteele/dotenv-webpack) which does this and more behind the scenes for you.
### What about variable expansion?
Try [dotenv-expand](https://github.com/motdotla/dotenv-expand)
### What about syncing and securing .env files?
Use [dotenvx](https://github.com/dotenvx/dotenvx) to unlock syncing encrypted .env files over git.
### What if I accidentally commit my `.env` file to code?
Remove it, [remove git history](https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/removing-sensitive-data-from-a-repository) and then install the [git pre-commit hook](https://github.com/dotenvx/dotenvx#pre-commit) to prevent this from ever happening again.
```
brew install dotenvx/brew/dotenvx
dotenvx precommit --install
```
### How can I prevent committing my `.env` file to a Docker build?
Use the [docker prebuild hook](https://dotenvx.com/docs/features/prebuild).
```bash
# Dockerfile
...
RUN curl -fsS https://dotenvx.sh/ | sh
...
RUN dotenvx prebuild
CMD ["dotenvx", "run", "--", "node", "index.js"]
```
## Contributing Guide
See [CONTRIBUTING.md](CONTRIBUTING.md)
## CHANGELOG

@@ -688,2 +783,4 @@

&nbsp;
## Who's using dotenv?

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