Let you import environment variables from a .env file in React Native, don't need any native code integration.

$ npm install react-native-dotenv --save-dev

Add the react-native-dotenv preset to your .babelrc file at the project root.

{
  "presets": ["react-native", "react-native-dotenv"]
}

If you haven't got .babelrc set up for React Native, remember to install babel-preset-react-native first.

$ npm install babel-preset-react-native --save-dev

Add your app configuration in an .env file.

API_KEY=lorem
ANOTHER_CONFIG=foobar

Now you can import it in your .js file.

import { API_KEY, ANOTHER_CONFIG } from 'react-native-dotenv'

ApiClient.init(API_KEY, ANOTHER_CONFIG)

As you can see, it's implemented as a babel plugin. All referenced imported members are replaced as the values specified in the .env file.

The example above will get compiled as below.

ApiClient.init('lorem', 'foobar')

Manually edit the file importing react-native-dotenv by either adding an empty line or whitespace will work.

Yes, simply create a separate .env.production file and the default release process of react-native will pickup the right config.

You can use the Release configuration to launch the Simulator. (Only supported in RN v0.39+)

react-native run-ios --configuration Release

1. Command⌘ + M to launch the developer menu in Android emulator.
2. Tap DevSettings.
3. Toggle JS Dev Mode.

Sadly, it's not available so far. One of the workaround is generating .env file before triggering RN's bundle script automatically using either shell script or your own custom build pipeline.

David Chang @zetachang

MIT License, see LICENSE file for detail.