Summary

I’m requesting first-class Expo support for multiple environment configuration files such as:

app.json (default)

app.dev.json

app.staging.json

app.production.json

Expo should automatically load the appropriate file based on the selected build profile (e.g., EAS --profile staging) and fall back to app.json when a key is not overridden. This would eliminate the need for custom logic in app.config.ts and create a clean, scalable configuration system for multi-environment apps.

Problem

Many Expo apps require different settings across environments:

App name & slug

Bundle identifiers / package names

API endpoints

Feature flags

Deep link configs

Runtime and update settings

Right now, developers must manually implement these differences using JavaScript logic inside app.config.ts. A typical setup looks like this:

Conditional names

Conditional icons

Conditional bundle IDs

Conditional package names

Conditional schemes

Conditional runtime settings

This results in large, complex, and repetitive configuration logic, and Cannot automatically write to dynamic config at: app.config.ts

Current Workaround (TypeScript Example)

Here is the kind of environment-switching logic developers currently need to maintain:

name: process.env.APP_ENV === "production" ? "The App" : ,

slug: process.env.APP_ENV === "production" ? "theapp" : ,

ios: {

bundleIdentifier:

process.env.APP_ENV === "production"

? "com.theappt"

: ,

},

android: {

package:

process.env.APP_ENV === "production"

? "com.theappt"

: ,

},

This manual branching works, but it leads to config sprawl and is easy to break over time.

Proposal: Native Environment-Based Config Files

Expo should support the following behaviour:

app.json // Base config for all environments

app.dev.json // Overrides for development

app.staging.json // Overrides for staging

app.production.json // Overrides for production

Examples:

eas build --profile staging → loads app.staging.json

EXPO_ENV=dev expo start → loads app.dev.json

If a field is missing in app.staging.json, Expo should automatically use the value from app.json before failing.

Example:

Plugins defined once in app.json

Only environment-specific values go into the env file

Reduces duplication dramatically

Expo should apply:

app.{env}.json overrides app.json

Unspecified keys fall back to app.json.

Benefits

Much cleaner configuration

Significantly reduced duplication

Eliminates the need for large JS/TS conditionals

Easier onboarding for new team members

Works naturally with EAS profiles

Less risk of breaking bundle IDs or package names

More aligned with how other platforms handle env-based config files

Why This Matters

Environment-based configuration is a core requirement for most production apps. Many Expo developers already simulate this manually using code, but the ecosystem would benefit greatly from a first-class, fully supported system.

This feature would modernise Expo’s config experience and simplify builds across all environments.