Apache OpenDAL™ Dart Binding (WIP)

A Dart binding for Apache OpenDAL: access S3, GCS, Azure Blob, the local filesystem, and 50+ more services through one API. Built on the Rust core via flutter_rust_bridge.

We release the OpenDAL Dart binding independently of the opendal crate (Rust core). For updates and compatibility, use the Dart binding version instead of the opendal crate version.

Useful Links

• User guide: opendal.apache.org/docs/bindings/dart
• Examples: examples/
• Services & configuration: opendal.apache.org/services
• Source: bindings/dart/

Installation

This binding is not yet published to pub.dev. To use it, clone the repository and add it as a path dependency, or work directly from bindings/dart/.

You must compile the Rust native library first:

cd rust
cargo build -r
cd ..
dart pub get

The loader first looks for the library in the platform-specific target-triple directory (e.g. rust/target/aarch64-apple-darwin/release/), then falls back to rust/target/release/. For cross-compiled targets, build with --target <triple> so the library is placed in the matching target directory.

Quickstart

import 'dart:typed_data';
import 'package:opendal/opendal.dart';

void main() async {
  final storage = await Storage.init(schemeStr: "memory", map: {"root": "/"});
  final File = storage.initFile();

  final file = File("hello.txt");
  await file.write(Uint8List.fromList("Hello, OpenDAL!".codeUnits));

  final data = await file.read();
  print(String.fromCharCodes(data)); // Hello, OpenDAL!

  await file.delete();
}

The API mirrors dart:io — Storage.initFile() and Storage.initDir() return factory functions that behave like dart:io's File and Directory.

Every method has a blocking *Sync variant alongside the async Future<T> form.

See the user guide for more examples and a full operations reference.

Contributing

Run tests after building the native library:

dart test

Update generated code when upgrading flutter_rust_bridge:

1. Install the matching flutter_rust_bridge_codegen version.
2. Update flutter_rust_bridge in both pubspec.yaml and rust/Cargo.toml.
3. Run flutter_rust_bridge_codegen generate.
4. Run cargo build -r from rust/.
5. Run dart test to verify.

The codegen version recorded in generated files, lib/src/rust/frb_generated.dart, and rust/src/frb_generated.rs must all match. Version drift causes startup or test failures.

License and Trademarks

Licensed under the Apache License, Version 2.0: http://www.apache.org/licenses/LICENSE-2.0

Apache OpenDAL, OpenDAL, and Apache are either registered trademarks or trademarks of the Apache Software Foundation.