Expo Env Load Behavior

Expo has different behavior on how it loads env variables on dev server, EAS Build, and EAS Updates

• On dev server and EAS Updates, by default it will load .env

• On EAS Build (unless we upload .env to EAS Build or exclude .env* from .gitignore), it’s recommended to define it in eas.json. EAS build only has access to files being not ignored through gitignore and EAS secrets.

• To make sure EAS Updates load the desired env:

  1. Define NODE_ENV and .env.${ENVIRONMENT_NAME}. For example we want to use .env.production:
  2. Add --clear-cache to make sure it load the most fresh value

  npx cross-env NODE_ENV=production eas update --channel production --message "fix issues"

  • references: https://github.com/expo/eas-cli/issues/2174#issuecomment-2053109651

References:

• https://docs.expo.dev/guides/environment-variables/
  • https://docs.expo.dev/build-reference/variables/#can-eas-build-use-env-files
  • https://docs.expo.dev/eas-update/environment-variables/#using-env-files-with-eas-update
• https://docs.expo.dev/build-reference/android-builds/
• https://docs.expo.dev/build-reference/ios-builds/