Load your environment configuration in a easy way and only one time.


Load your environment configuration in a easy way and call in your code only one time and will be available through "process.env".


It's possible to reload the environment configuration by change the config file. Attention, process.env convert all values to string, must cast in case isn't a string, ex:

port number for your web server => 3000

console.log(process.env.WEB_PORT);// is going be '3000'
console.log(Number(process.env.WEB_PORT));// is going be 3000

a JSON object with some options => {port: 4000, address: 'localhost'}

// is gonna be '{"port":4000,"address":"localhost"}'
// internally we are using JSON.stringify

// is gonna be { port: 4000, address: 'localhost' }

If wants to get the primitive value of the specified object can use process.loadenv.'key' and don't need to do any conversion.

 typeof process.loadenv.MONGODB_URL === 'string'
 typeof process.loadenv.APP_PORT === 'number'
 isJSON(process.loadenv.WINDOW_SIZE, true)


var load = require('load-env') or require('load-env')()

load([environment], [config_path], [reload*])

*reload accepts a bool (default to false/null), if wants to reload the enviroment when the configuration file is updated then pass true.

from CLI: node my_app --env heroku

in your app just need to make the require and call load();

--env is mandatory in CLI

config folder must be in your application current directory or can use [path] to define the localization of your config files, and the files must have the exactly name as your environment (heroku.json will be env heroku).



####JSON strutucture for config file

{"var_name": {"format": "", "value":""}}

format: value with placeholders
    %s - String
    %d - Number (both integer and float)
    %j - JSON
value: object with the values to replace the placeholders


      "MONGODB_URL": {
        "format": "mongodb://%s:%s@%s/%s?%s",
        "value" : {
          "user": "xpto",
          "pwd": "password",
          "host": "ec2-22-197-555-120.compute-100.amazonaws.com",
          "db": "lilidb",
          "extra": "numberOfRetries=10&retryMiliSeconds=10000"
      "APP_PORT": {
        "format": "%d",
        "value" : {
          "port": 4000

   // now in your code

   require('load-env')(); // var load = require('load-env'); load();

   console.log(process.env.MONGODB_URL); // 'conn_str'
   console.log(process.env.APP_PORT); // '4000'
   console.log(process.loadenv.MONGODB_URL); // 'conn_str'
   console.log(process.loadenv.APP_PORT); // 4000
   // CLI
   node my_app --env heroku
    "format": "%j",
    "value": {
      "sizes": {
        "width": 1000,
        "height": 600,
        "min-width": 800,
        "min-height": 600

// we are using %j to specify is a JSON

call process.loadenv.WINDOW_SIZE will return the the JSON already parsed

{ width: 1000, height: 600, 'min-width': 800, 'min-height': 600 }

call process.env.WINDOW_SIZE must use the JSON.parse