dart:ffi bindings to the immich_native_core Rust core. The native code is built from source on every app build via a Dart build hook (Flutter native assets) — no prebuilt binaries, no DynamicLibrary, no platform plugin glue.

Use it from immich/mobile

# mobile/pubspec.yaml
dependencies:
  immich_native_core:
    path: ../native/immich_native_core

dart pub get. The dart surface is exactly the ffigen output of the C header — the current capabilities (EXIF rotate, 10-bit convert, thumbhash decode) are called by the platform decode pipelines, not by dart, so there are no hand-written dart wrappers. Add one only when a dart feature actually consumes a function.

No app-level Gradle/Podfile edits. hook/build.dart compiles the Rust crate and Flutter bundles it as a code asset; the @Native bindings resolve against it. Requirement: every machine that builds the app needs rustup — the hook auto-installs the pinned toolchain + targets from the crate's rust-toolchain.toml.

Layout

hook/build.dart — builds ../crates/immich_core_ffi via native_toolchain_rust.
lib/immich_native_core.dart — barrel; re-exports the generated bindings.
lib/src/ffi/bindings.g.dart — ffigen @Native output (committed; do not edit).
ffigen.yaml — ffi-native mode; asset-id must match the hook's assetName.
test/ — host FFI roundtrip (flutter test); device runs via mobile/integration_test.

⚠ iOS App Extensions

Code assets are bundled into the app's Runner target. immich ships a Share Extension and a Widget Extension — if the core is ever called from one of those, verify the symbols resolve there (same family as the embed-into-Runner-only gotcha). Not an issue while only the main app calls it.

The Rust workspace, the codegen/build/test commands, and the "add a function" loop live in ../README.md.