Expo Atlas

Inspect your Metro bundle, on module level.

Warning

This project is unstable and might not work for your project.

🚀 How to use it

Atlas is built into Expo starting from SDK 51, and enabled when defining the environment variable EXPO_UNSTABLE_ATLAS=true.

You can use Atlas with two Expo commands:

• $ expo start → Start a local dev server, Atlas will listen to any change within your project.
• $ expo export → Export your app to Android, iOS, or web. Atlas will generate the atlas.jsonl file.

Using $ expo start

When enabling Atlas with the local dev server, you can access Atlas on http://localhost:8081/_expo/atlas. This shows you all information from the bundle loaded during development.

$ EXPO_UNSTABLE_ATLAS=true npx expo start

Tip

Expo start runs in development mode by default. If you want to see a production bundle of your app, you can start the local dev server in production mode: $ expo start --no-dev --no-minify.

Using $ expo export

When enabling Atlas during exports, Expo generates the .expo/atlas.json file in your project. This file contains all bundle information, including the actual source code of individual files. You can open the Atlas file through npx expo-atlas [path/to/atlas.jsonl].

# Export the app for all platforms
$ EXPO_UNSTABLE_ATLAS=true npx expo export --platform all

# Open Atlas using the default `.expo/atlas.jsonl` path
$ npx expo-atlas
# Open Atlas from a shared file
$ npx expo-atlas ./path/to/atlas.jsonl

with ❤️  Expo