.. or using ES6?
That's it. process.env now has the keys and values you defined in your .env file:
If you need multiline variables, for example private keys, those are now supported (>= v15.0.0 ) with line breaks:
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.
The configuration options below are supported as command line arguments in the format `dotenv_config_
=value`
` ` ` sh $ 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.
` ` ` sh $ DOTENV_CONFIG_ < OPTION >= value node - r dotenv / config your_script .js ` ` `
` ` ` sh $ 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 .
Syncing
You need to keep
.env files in sync between machines, environments, or team members? Use
dotenv-vault .
Examples
See
examples of using dotenv with various frameworks, languages, and configurations.
Documentation
Dotenv exposes two functions:
config
parse
Config
config will read your .env file, parse the contents, assign it to
[process.env ](https://nodejs.org/docs/latest/api/process.html#process_process_env),
and return an Object with a parsed key containing the loaded content or an error key if it failed.
` ` ` js 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.
` ` ` js require ( 'dotenv' ) .config ( { path : '/custom/path/to/.env' } ) ` ` `
Encoding
Default: utf8
Specify the encoding of your file containing environment variables.
` ` ` js 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.
` ` ` js 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.
` ` ` js require ( 'dotenv' ) .config ( { override : true } ) ` ` `
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.
` ` ` js 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.
` ` ` js 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 ` ` `
FAQ
Why is the .env file not loading my environment variables successfully?
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?
No. We strongly recommend against having a "main" .env file and an "environment" .env file like .env.test . Your config should vary between deploys, and you should not be sharing values between environments.
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.
>
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.
` ` ` js 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 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..
` ` ` js // index.mjs (ESM) import * as dotenv from 'dotenv' // see https://github.com/motdotla/dotenv#how-do-i-use-dotenv-with-import dotenv .config ( ) 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.
>
What does this mean in plain language? It means you would think the following would work but it won't.
` ` ` js // errorReporter.mjs import { Client } from 'best-error-reporting-service' export default new Client ( process .env .API_KEY ) // index.mjs import dotenv from 'dotenv' dotenv .config ( ) import errorReporter from './errorReporter.mjs' errorReporter .report ( new Error ( 'documented example' ) ) ` ` `
process.env.API_KEY will be blank.
Instead the above code should be written as..
` ` ` js // errorReporter.mjs import { Client } from 'best-error-reporting-service' export default new Client ( process .env .API_KEY ) // index.mjs import * as dotenv from 'dotenv' dotenv .config ( ) import errorReporter from './errorReporter.mjs' errorReporter .report ( new Error ( 'documented example' ) ) ` ` `
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_)
What about variable expansion?
What about syncing and securing .env files?
Contributing Guide
CHANGELOG
Who's using dotenv?
探客时代
