Important: This documentation covers Yarn 1 (Classic).
For Yarn 2+ docs and migration guide, see yarnpkg.com.

Package detail

dotenv

motdotla204.6mBSD-2-Clause16.4.7TypeScript support: included

Loads environment variables from .env file

dotenv, env, .env, environment, variables, config, settings

readme

🎉 announcing dotenvx. run anywhere, multi-environment, encrypted envs.

 

dotenv NPM version

dotenv

Dotenv is a zero-dependency module that loads environment variables from a .env file into process.env. Storing configuration in the environment separate from code is based on The Twelve-Factor App methodology.

js-standard-style LICENSE codecov

🌱 Install

# install locally (recommended)
npm install dotenv --save

Or installing with yarn? yarn add dotenv

🏗️ Usage

how to use dotenv video tutorial youtube/@dotenvorg

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):

S3_BUCKET="YOURS3BUCKET"
SECRET_KEY="YOURSECRETKEYGOESHERE"

As early as possible in your application, import and configure dotenv:

require('dotenv').config()
console.log(process.env) // remove this after you've confirmed it is working

.. or using ES6?

import 'dotenv/config'

That's it. process.env now has the keys and values you defined in your .env file:

require('dotenv').config()
// or import 'dotenv/config' if you're using ES6

...

s3.getBucketCors({Bucket: process.env.S3_BUCKET}, function(err, data) {})

Multiline values

If you need multiline variables, for example private keys, those are now supported (>= v15.0.0) with line breaks:

PRIVATE_KEY="-----BEGIN RSA PRIVATE KEY-----
...
Kh9NV...
...
-----END RSA PRIVATE KEY-----"

Alternatively, you can double quote strings and use the \n character:

PRIVATE_KEY="-----BEGIN RSA PRIVATE KEY-----\nKh9NV...\n-----END RSA PRIVATE KEY-----\n"

Comments

Comments may be added to your file on their own line or inline:

# This is a comment
SECRET_KEY=YOURSECRETKEYGOESHERE # comment
SECRET_HASH="something-with-a-#-hash"

Comments begin where a # exists, so if your value contains a # please wrap it in quotes. This is a breaking change from >= v15.0.0 and on.

Parsing

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.

const dotenv = require('dotenv')
const buf = Buffer.from('BASIC=basic')
const config = dotenv.parse(buf) // will return an object
console.log(typeof config, config) // object { BASIC : 'basic' }

Preload

Note: Consider using 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

You can use the --require (-r) command line option to preload dotenv. By doing this, you do not need to require and load dotenv in your application code.

$ node -r dotenv/config your_script.js

The configuration options below are supported as command line arguments in the format dotenv_config_<option>=value

$ node -r dotenv/config your_script.js dotenv_config_path=/custom/path/to/.env dotenv_config_debug=true

Additionally, you can use environment variables to set configuration options. Command line arguments will precede these.

$ DOTENV_CONFIG_<OPTION>=value node -r dotenv/config your_script.js
$ DOTENV_CONFIG_ENCODING=latin1 DOTENV_CONFIG_DEBUG=true node -r dotenv/config your_script.js dotenv_config_path=/custom/path/to/.env

Variable Expansion

You need to add the value of another variable in one of your variables? Use dotenv-expand.

Command Substitution

Use dotenvx to use command substitution.

Add the output of a command to one of your variables in your .env file.

# .env
DATABASE_URL="postgres://$(whoami)@localhost/my_database"
// index.js
console.log('DATABASE_URL', process.env.DATABASE_URL)
$ dotenvx run --debug -- node index.js
[dotenvx@0.14.1] injecting env (1) from .env
DATABASE_URL postgres://yourusername@localhost/my_database

Syncing

You need to keep .env files in sync between machines, environments, or team members? Use 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.

Multiple Environments

Use dotenvx to generate .env.ci, .env.production files, and more.

Deploying

You need to deploy your secrets in a cloud-agnostic manner? Use dotenvx to generate a private decryption key that is set on your production server.

🌴 Manage Multiple Environments

Use dotenvx

Run any environment locally. Create a .env.ENVIRONMENT file and use --env-file to load it. It's straightforward, yet flexible.

$ echo "HELLO=production" > .env.production
$ echo "console.log('Hello ' + process.env.HELLO)" > index.js

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

or with multiple .env files

$ echo "HELLO=local" > .env.local
$ echo "HELLO=World" > .env
$ echo "console.log('Hello ' + process.env.HELLO)" > index.js

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

more environment examples

🚀 Deploying

Use dotenvx.

Add encryption to your .env files with a single command. Pass the --encrypt flag.

$ 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

learn more

📚 Examples

See examples of using dotenv with various frameworks, languages, and configurations.

📖 Documentation

Dotenv exposes four functions:

  • config
  • parse
  • populate
  • decrypt

Config

config will read your .env file, parse the contents, assign it to process.env, and return an Object with a parsed key containing the loaded content or an error key if it failed.

const result = dotenv.config()

if (result.error) {
  throw result.error
}

console.log(result.parsed)

You can additionally, pass options to config.

Options

path

Default: path.resolve(process.cwd(), '.env')

Specify a custom path if your file containing environment variables is located elsewhere.

require('dotenv').config({ path: '/custom/path/to/.env' })

By default, config will look for a file called .env in the current working directory.

Pass in multiple files as an array, and they will be parsed in order and combined with process.env (or option.processEnv, if set). The first value set for a variable will win, unless the options.override flag is set, in which case the last value set will win. If a value already exists in process.env and the options.override flag is NOT set, no changes will be made to that value.

require('dotenv').config({ path: ['.env.local', '.env'] })
encoding

Default: utf8

Specify the encoding of your file containing environment variables.

require('dotenv').config({ encoding: 'latin1' })
debug

Default: false

Turn on logging to help debug why certain keys or values are not being set as you expect.

require('dotenv').config({ debug: process.env.DEBUG })
override

Default: false

Override any environment variables that have already been set on your machine with values from your .env file(s). If multiple files have been provided in option.path the override will also be used as each file is combined with the next. Without override being set, the first value wins. With override set the last value wins.

require('dotenv').config({ override: true })
processEnv

Default: process.env

Specify an object to write your secrets to. Defaults to process.env environment variables.

const myObject = {}
require('dotenv').config({ processEnv: myObject })

console.log(myObject) // values from .env
console.log(process.env) // this was not changed or written to

Parse

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.

const dotenv = require('dotenv')
const buf = Buffer.from('BASIC=basic')
const config = dotenv.parse(buf) // will return an object
console.log(typeof config, config) // object { BASIC : 'basic' }

Options

debug

Default: false

Turn on logging to help debug why certain keys or values are not being set as you expect.

const dotenv = require('dotenv')
const buf = Buffer.from('hello world')
const opt = { debug: true }
const config = dotenv.parse(buf, opt)
// expect a debug message because the buffer is not in KEY=VAL form

Populate

The engine which populates the contents of your .env file to process.env is available for use. It accepts a target, a source, and options. This is useful for power users who want to supply their own objects.

For example, customizing the source:

const dotenv = require('dotenv')
const parsed = { HELLO: 'world' }

dotenv.populate(process.env, parsed)

console.log(process.env.HELLO) // world

For example, customizing the source AND target:

const dotenv = require('dotenv')
const parsed = { HELLO: 'universe' }
const target = { HELLO: 'world' } // empty object

dotenv.populate(target, parsed, { override: true, debug: true })

console.log(target) // { HELLO: 'universe' }

options

Debug

Default: false

Turn on logging to help debug why certain keys or values are not being populated as you expect.

override

Default: false

Override any environment variables that have already been set.

❓ FAQ

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.

Turn on debug mode and try again..

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

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) (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.

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, which is distributed through create-react-app, it has dotenv built in but with a quirk. Preface your environment variables with REACT_APP_. See this stack overflow 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:

const dotenv = require('dotenv')
const variableExpansion = require('dotenv-expand')
const myEnv = dotenv.config()
variableExpansion(myEnv)

How do I use dotenv with import?

Simply..

// 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

What does this mean in plain language? It means you would think the following would work but it won't.

errorReporter.mjs:

import { Client } from 'best-error-reporting-service'

export default new Client(process.env.API_KEY)

index.mjs:

// Note: this is INCORRECT and will not work
import * as dotenv from 'dotenv'
dotenv.config()

import errorReporter from './errorReporter.mjs'
errorReporter.report(new Error('documented example'))

process.env.API_KEY will be blank.

Instead, index.mjs should be written as..

import 'dotenv/config'

import errorReporter from './errorReporter.mjs'
errorReporter.report(new Error('documented example'))

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.

There are two alternatives to this approach:

  1. Preload dotenv: node --require dotenv/config 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

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:

npm install node-polyfill-webpack-plugin

Configure your webpack.config.js to something like the following.

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 which does this and more behind the scenes for you.

What about variable expansion?

Try dotenv-expand

What about syncing and securing .env files?

Use dotenvx

What if I accidentally commit my .env file to code?

Remove it, remove git history and then install the git pre-commit hook 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.

# Dockerfile
...
RUN curl -fsS https://dotenvx.sh/ | sh
...
RUN dotenvx prebuild
CMD ["dotenvx", "run", "--", "node", "index.js"]

Contributing Guide

See CONTRIBUTING.md

CHANGELOG

See CHANGELOG.md

Who's using dotenv?

These npm modules depend on it.

Projects that expand it often use the keyword "dotenv" on npm.

changelog

Changelog

All notable changes to this project will be documented in this file. See standard-version for commit guidelines.

Unreleased

[16.4.7](https://github.com/motdotla/dotenv/compare/v16.4.6...v16.4.7 (2024-12-03)

Changed

  • Ignore .tap folder when publishing. (oops, sorry about that everyone. - @motdotla) #848

16.4.6 (2024-12-02)

Changed

  • Clean up stale dev dependencies #847
  • Various README updates clarifying usage and alternative solutions using dotenvx

16.4.5 (2024-02-19)

Changed

  • 🐞 Fix recent regression when using path option. return to historical behavior: do not attempt to auto find .env if path set. (regression was introduced in 16.4.3) #814

16.4.4 (2024-02-13)

Changed

  • 🐞 Replaced chaining operator ?. with old school && (fixing node 12 failures) #812

16.4.3 (2024-02-12)

Changed

  • Fixed processing of multiple files in options.path #805

16.4.2 (2024-02-10)

Changed

16.4.1 (2024-01-24)

  • Patch support for array as path option #797

16.4.0 (2024-01-23)

  • Add error.code to error messages around .env.vault decryption handling #795
  • Add ability to find .env.vault file when filename(s) passed as an array #784

16.3.2 (2024-01-18)

Added

  • Add debug message when no encoding set #735

Changed

  • Fix output typing for populate #792
  • Use subarray instead of slice #793

16.3.1 (2023-06-17)

Added

  • Add missing type definitions for processEnv and DOTENV_KEY options. #756

16.3.0 (2023-06-16)

Added

  • Optionally pass DOTENV_KEY to options rather than relying on process.env.DOTENV_KEY. Defaults to process.env.DOTENV_KEY #754

16.2.0 (2023-06-15)

Added

  • Optionally write to your own target object rather than process.env. Defaults to process.env. #753
  • Add import type URL to types file #751

16.1.4 (2023-06-04)

Added

  • Added .github/ to .npmignore #747

16.1.3 (2023-05-31)

Removed

  • Removed browser keys for path, os, and crypto in package.json. These were set to false incorrectly as of 16.1. Instead, if using dotenv on the front-end make sure to include polyfills for path, os, and crypto. node-polyfill-webpack-plugin provides these.

16.1.2 (2023-05-31)

Changed

  • Exposed private function _configDotenv as configDotenv. #744

16.1.1 (2023-05-30)

Added

  • Added type definition for decrypt function

Changed

  • Fixed {crypto: false} in packageJson.browser

16.1.0 (2023-05-30)

Added

  • Add populate convenience method #733
  • Accept URL as path option #720
  • Add dotenv to npm fund command
  • Spanish language README #698
  • Add .env.vault support. 🎉 (#730)

ℹ️ .env.vault extends the .env file format standard with a localized encrypted vault file. Package it securely with your production code deploys. It's cloud agnostic so that you can deploy your secrets anywhere – without risky third-party integrations. read more

Changed

  • Fixed "cannot resolve 'fs'" error on tools like Replit #693

16.0.3 (2022-09-29)

Changed

  • Added library version to debug logs (#682)

16.0.2 (2022-08-30)

Added

  • Export env-options.js and cli-options.js in package.json for use with downstream dotenv-expand module

16.0.1 (2022-05-10)

Changed

  • Minor README clarifications
  • Development ONLY: updated devDependencies as recommended for development only security risks (#658)

16.0.0 (2022-02-02)

Added

  • Breaking: Backtick support 🎉 (#615)

If you had values containing the backtick character, please quote those values with either single or double quotes.

15.0.1 (2022-02-02)

Changed

  • Properly parse empty single or double quoted values 🐞 (#614)

15.0.0 (2022-01-31)

v15.0.0 is a major new release with some important breaking changes.

Added

  • Breaking: Multiline parsing support (just works. no need for the flag.)

Changed

  • Breaking: # marks the beginning of a comment (UNLESS the value is wrapped in quotes. Please update your .env files to wrap in quotes any values containing #. For example: SECRET_HASH="something-with-a-#-hash").

..Understandably, (as some teams have noted) this is tedious to do across the entire team. To make it less tedious, we recommend using dotenv cli going forward. It's an optional plugin that will keep your .env files in sync between machines, environments, or team members.

Removed

  • Breaking: Remove multiline option (just works out of the box now. no need for the flag.)

14.3.2 (2022-01-25)

Changed

  • Preserve backwards compatibility on values containing # 🐞 (#603)

14.3.1 (2022-01-25)

Changed

  • Preserve backwards compatibility on exports by re-introducing the prior in-place exports 🐞 (#606)

14.3.0 (2022-01-24)

Added

  • Add multiline option 🎉 (#486)

14.2.0 (2022-01-17)

Added

  • Add dotenv_config_override cli option
  • Add DOTENV_CONFIG_OVERRIDE command line env option

14.1.1 (2022-01-17)

Added

  • Add React gotcha to FAQ on README

14.1.0 (2022-01-17)

Added

  • Add override option 🎉 (#595)

14.0.1 (2022-01-16)

Added

  • Log error on failure to load .env file (#594)

14.0.0 (2022-01-16)

Added

  • Breaking: Support inline comments for the parser 🎉 (#568)

13.0.1 (2022-01-16)

Changed

  • Hide comments and newlines from debug output (#404)

13.0.0 (2022-01-16)

Added

  • Breaking: Add type file for config.js (#539)

12.0.4 (2022-01-16)

Changed

  • README updates
  • Minor order adjustment to package json format

12.0.3 (2022-01-15)

Changed

  • Simplified jsdoc for consistency across editors

12.0.2 (2022-01-15)

Changed

  • Improve embedded jsdoc type documentation

12.0.1 (2022-01-15)

Changed

  • README updates and clarifications

12.0.0 (2022-01-15)

Removed

  • Breaking: drop support for Flow static type checker (#584)

Changed

  • Move types/index.d.ts to lib/main.d.ts (#585)
  • Typescript cleanup (#587)
  • Explicit typescript inclusion in package.json (#566)

11.0.0 (2022-01-11)

Changed

  • Breaking: drop support for Node v10 (#558)
  • Patch debug option (#550)

10.0.0 (2021-05-20)

Added

  • Add generic support to parse function
  • Allow for import "dotenv/config.js"
  • Add support to resolve home directory in path via ~

9.0.2 (2021-05-10)

Changed

  • Support windows newlines with debug mode

9.0.1 (2021-05-08)

Changed

  • Updates to README

9.0.0 (2021-05-05)

Changed

  • Breaking: drop support for Node v8

8.6.0 (2021-05-05)

Added

  • define package.json in exports

8.5.1 (2021-05-05)

Changed

  • updated dev dependencies via npm audit

8.5.0 (2021-05-05)

Added

  • allow for import "dotenv/config"

8.4.0 (2021-05-05)

Changed

  • point to exact types file to work with VS Code

8.3.0 (2021-05-05)

Changed

  • Breaking: drop support for Node v8 (mistake to be released as minor bump. later bumped to 9.0.0. see above.)

8.2.0 (2019-10-16)

Added

  • TypeScript types

8.1.0 (2019-08-18)

Changed

  • Breaking: drop support for Node v6 (#392)

8.0.0 (2019-05-02)

Changed

  • Breaking: drop support for Node v6 (#302)

7.0.0 - 2019-03-12

Fixed

  • Fix removing unbalanced quotes (#376)

Removed

  • Removed load alias for config for consistency throughout code and documentation.

6.2.0 - 2018-12-03

Added

  • Support preload configuration via environment variables (#351)

6.1.0 - 2018-10-08

Added

  • debug option for config and parse methods will turn on logging

6.0.0 - 2018-06-02

Changed

  • Breaking: drop support for Node v4 (#304)

5.0.0 - 2018-01-29

Added

  • Testing against Node v8 and v9
  • Documentation on trim behavior of values
  • Documentation on how to use with import

Changed

  • Breaking: default path is now path.resolve(process.cwd(), '.env')
  • Breaking: does not write over keys already in process.env if the key has a falsy value
  • using const and let instead of var

Removed

  • Testing against Node v7

4.0.0 - 2016-12-23

Changed

  • Return Object with parsed content or error instead of false (#165).

Removed

  • verbose option removed in favor of returning result.

3.0.0 - 2016-12-20

Added

  • verbose option will log any error messages. Off by default.
  • parses email addresses correctly
  • allow importing config method directly in ES6

Changed

  • Suppress error messages by default (#154)
  • Ignoring more files for NPM to make package download smaller

Fixed

  • False positive test due to case-sensitive variable (#124)

Removed

  • silent option removed in favor of verbose

2.0.0 - 2016-01-20

Added

Changed

  • README has shorter description not referencing ruby gem since we don't have or want feature parity

Removed

  • Variable expansion and escaping so environment variables are encouraged to be fully orthogonal

1.2.0 - 2015-06-20

Added

  • Preload hook to require dotenv without including it in your code

Changed

  • clarified license to be "BSD-2-Clause" in package.json

Fixed

  • retain spaces in string vars

1.1.0 - 2015-03-31

Added

  • Silent option to silence console.log when .env missing

1.0.0 - 2015-03-13

Removed

  • support for multiple .env files. should always use one .env file for the current environment