How to setup plain text env vars in Expo build? - react-native

Question

I'm working on an expo project and trying to link environment variables for build profiles. I was trying to achieve that using eas.json but I cannot get it to work.
I have two build profiles - development and production:
{
"cli": {
"version": ">= 3.3.1"
},
"build": {
"development": {
"distribution": "internal",
"env": {
"API_URL": "https://staging-api.example.com",
"STRIPE_ENV": "test"
},
"ios": {
"resourceClass": "m1-medium"
}
},
"production": {
"env": {
"API_URL": "https://api.example.com",
"STRIPE_ENV": "production"
},
"ios": {
"resourceClass": "m1-medium"
},
"autoIncrement": true
}
},
"submit": {
"production": {
...
}
}
}
Build command:
eas build --profile development --platform ios
Based on their documentation, I sohuld be able to use process.env.API_URL but it's undefined.
Am I missing something?

Answer 1

Putting those values in eas.json is only ensuring that those envs will be set during the build process on EAS. To pass them to the application code you need to pass those values to the extra field in app.config.js.
process.env.API_URL will be defined when evaluating app.config.js, but in your application code, you need to access those values via expo-constants package.