hook/build.dart Data assets support #146264

Update 2026-05-12: This is available under flutter config --enable-dart-data-assets. Please report any issues that you find.

Update 2026-09-29: With @RecordUse() info available in link hooks since Dart 3.13, this experiment can be used to do tree-shaking of assets (#64106).

The hook/build.dart of packages should be able to not only add native code assets, but also data assets.

In Flutter, these data assets should be made available through the existing asset bundle API.

This issue tracks the flutter implementation for this in flutter tools.

• Add data_asset to BuildConfig.supportedAssetTypes.
• Bundle the [DataAsset]s from BuildOutput.assets in Flutter applications (on all 5 OSes, in all modes).
  • Open question: should asset contents be refreshed on hot reload / hot restart?

Tracking issue for Dart and Flutter combined:

• [native_assets_cli] data assets dart-lang/native#154

Umbrella issue for native assets:

• ☂️ Build hooks & Code assets #129757

cc @mosuem @andrewkolos @christopherfujino