Asset selection and exclusion

Learn how to use the asset selection feature and verify that an update includes all required app assets.

Available for SDK 50 and above (expo-updates >= 0.23.0).

In SDK 49 and earlier, all assets resolved in the Metro bundler are included in every update and are uploaded to the update server. The experimental asset selection feature in SDK 50 allows the developer to specify that only certain assets should be included in updates. This can greatly reduce the number of assets that need to be uploaded to and downloaded from the updates server. This feature will work with the EAS Update server or any custom server that complies with the expo-updates protocol.

Using asset selection

To use the asset selection, include the property extra.updates.assetPatternsToBeBundled in your app config. It should define one or more file-matching patterns (regular expressions). For example, an app.json file has the patterns defined in the following way:

  "expo": {
    %%placeholder-start%%... %%placeholder-end%%
    "extra": {
      "updates": {
        "assetPatternsToBeBundled": [
          "app/images/**/*.png"
        ]
      }
    }
  }

After adding this configuration all .png files in all subdirectories of app/images will be included in updates. You have to also ensure that these assets need to be required in your JavaScript code

If assetPatternsToBeBundled isn't included in the app config, all assets resolved by the bundler will be included in updates (as per SDK 49 and earlier behavior).

Verifying that an update includes all required app assets

When using the asset selection, assets that do not match any file patterns will resolve in the Metro bundler. However, these assets will not be uploaded to the updates server. You have to be certain that assets not included in updates are built into the native build of the app.

If you are building your app locally or have access to the correct build for publishing updates (with the same runtime version), then use the npx expo-updates assets:verify command. It allows you to check whether all required assets will be included when you publish an update:

This new command is part of the expo-updates CLI, which also supports EAS Update code signing. It is not part of the Expo CLI or the EAS CLI. Only available for (expo-updates >= 0.24.10).

You can also use the --help option with the command to see the available options:

Example