React Native: process.env has only NODE_ENV

It’s important to know that the React-Native app is running on a device (or emulator) in an environment more like a browser, not a Node.js process.

For cross-compatibility with Node.js libraries that relies on process.env.NODE_ENV to perform optimizations, React-Native adds the process global variable with env.NODE_ENV.

If you want to pass custom constants to React-Native, you can use: https://github.com/luggit/react-native-config

You should install this plugin babel plugin

npm install babel-plugin-transform-inline-environment-variables --save-dev

Then add it to your babel config (.babelrc, babel.config.js) in the plugin section

{
  "plugins": [
    ["transform-inline-environment-variables", {
      "include": [
        "NODE_ENV"
      ]
    }]
  ]
}

Then when you pass the variable through the inline like

API_KEY=dev && react-native run-android

You should get it through

process.env.API_KEY

And the value will be dev

This work for me on Mac terminal, Hope it answer your question

EDIT:
I added a double “&” because only one doesn’t work.

Nothing worked out from these answers here, as well as React Native Expo Environment Variables, but I’ve found react-native-dotenv.

It did the trick:

1. Terminal: yarn add react-native-dotenv --dev
2. In babel.config.js (or .babelrc): add "module:react-native-dotenv" to plugins
3. In your component, import { REST_API_KEY } from "@env"; at the top
4. In your component, use as alert(REST_API_KEY);

Of course, with the alert, that’s a dummy example 🙂

The easiest way I found to solve this problem is by using the react-native-config library that you can have a look at here.

1. Install the library:

$ yarn add react-native-config

2. Create your .env file with your content. For example:

GOOGLE_MAPS_API_KEY=abcdefgh

3. Import Config from react-native-config and use your variables.

import Config from "react-native-config";
...
console.log('ENV:', Config.GOOGLE_MAPS_API_KEY); // ENV: abcdefgh

P.S.: After installing the package you need to run npx pod-install to auto-link it or if your React Native version is older than 0.60, link it manually following the instructions on the library.

add babel-plugin-transform-inline-environment-variables

npm install babel-plugin-transform-inline-environment-variables --save-dev

babel.config.js:

{
  "plugins": [
    ["transform-inline-environment-variables"],
  ]
}

do not add "include": ["NODE_ENV"]

then run API_KEY=testKey && react-native start
and then you can use API_KEY via process.env.API_KEY,

but it is weird that console.log(process.env) only show a {NODE_ENV: "development"},do not contain API_KEY