onnxruntime_plus

pub package

Fork Status

This package is a fork of the original onnxruntime Flutter plugin. It is kept mainly to ship Apple packaging fixes, especially iOS Swift Package Manager support, and related compatibility updates that are not available in the older package.

Maintenance is best-effort and focused on keeping the package usable for current projects, not on broad feature development.

Overview

Flutter plugin for ONNX Runtime via dart:ffi with iOS Swift Package Manager support and cross-platform Dart bindings.

Platform Android iOS Linux macOS Windows
Compatibility API level 21+ * * * *
Architecture arm32/arm64 * * * *

*: Consistent with Flutter

Key Features

  • Multi-platform Support for Android, iOS, Linux, macOS, Windows, and Web(Coming soon).
  • Flexibility to use any Onnx Model.
  • Acceleration using multi-threading.
  • Similar structure as OnnxRuntime Java and C# API.
  • Inference speed is not slower than native Android/iOS Apps built using the Java/Objective-C API.
  • Run inference in different isolates to prevent jank in UI thread.

Getting Started

In your flutter project add the dependency:

dependencies:
  ...
  onnxruntime_plus: x.y.z

Usage example

Import

import 'package:onnxruntime_plus/onnxruntime_plus.dart';

Initializing environment

OrtEnv.instance.init();

Creating the Session

final sessionOptions = OrtSessionOptions();
const assetFileName = 'assets/models/test.onnx';
final rawAssetFile = await rootBundle.load(assetFileName);
final bytes = rawAssetFile.buffer.asUint8List();
final session = OrtSession.fromBuffer(bytes, sessionOptions!);

Performing inference

final shape = [1, 2, 3];
final inputOrt = OrtValueTensor.createTensorWithDataList(data, shape);
final inputs = {'input': inputOrt};
final runOptions = OrtRunOptions();
final outputs = await _session?.runAsync(runOptions, inputs);
inputOrt.release();
runOptions.release();
outputs?.forEach((element) {
  element?.release();
});

Releasing environment

OrtEnv.instance.release();

Apple packaging

For iOS, this package supports both CocoaPods fallback and Swift Package Manager integration. The Swift package uses the official ONNX Runtime iOS binary archive published by Microsoft. This fork also keeps Apple package metadata in sync for newer Flutter package-manager expectations.

Libraries

onnxruntime_plus