Overview
The RunAnywhere Flutter SDK is a production-grade, on-device AI SDK for Flutter applications. It enables developers to run AI models directly on iOS and Android devices without requiring network connectivity for inference, ensuring minimal latency and maximum privacy for your users. The SDK provides a unified interface to multiple AI capabilities:LLM
Text generation with streaming support via Dart Streams
STT
Speech-to-text transcription with Whisper models
TTS
Neural voice synthesis with Piper TTS
VAD
Real-time voice activity detection with Silero VAD
Key Capabilities
- Multi-backend architecture – Choose from LlamaCPP (GGUF models) or ONNX Runtime
- Cross-platform – Single codebase for iOS and Android
- Dart-native – Built with async/await and Streams for reactive programming
- Production-ready – Built-in analytics, logging, and model lifecycle management
Core Philosophy
On-Device First
On-Device First
All AI inference runs locally, ensuring low latency and data privacy. Once models are
downloaded, no network connection is required for inference.
Modular Backends
Modular Backends
Backend engines are separate packages—include only what you need. This keeps your app bundle
size minimal.
Privacy by Design
Privacy by Design
Audio and text data never leaves the device unless explicitly configured. Only anonymous
analytics are collected by default.
Event-Driven
Event-Driven
Subscribe to SDK events for reactive UI updates and observability.
Features
Language Models (LLM)
- On-device text generation with streaming support
- Dart Stream-based token streaming
- System prompts and customizable generation parameters
- Support for thinking/reasoning models
- LlamaCPP backend for GGUF models
Speech-to-Text (STT)
- Real-time streaming transcription
- Batch audio transcription
- Multi-language support
- Whisper-based models via ONNX Runtime
Text-to-Speech (TTS)
- Neural voice synthesis with Piper TTS
- System voices via platform TTS
- Streaming audio generation for long text
- Customizable voice, pitch, rate, and volume
Voice Activity Detection (VAD)
- Energy-based speech detection with Silero VAD
- Configurable sensitivity thresholds
- Real-time audio stream processing
Voice Agent Pipeline
- Full VAD → STT → LLM → TTS orchestration
- Complete voice conversation flow
- Push-to-talk and hands-free modes
System Requirements
| Platform | Minimum Version |
|---|---|
| Flutter | 3.10.0+ |
| Dart | 3.0.0+ |
| iOS | 14.0+ |
| Android | API 24 (7.0+) |
ARM64 devices are recommended for best performance. Metal GPU acceleration on iOS and NEON SIMD on
Android provide significant speedups over CPU-only inference.
Package Composition
| Package | Size | Purpose |
|---|---|---|
runanywhere | ~5MB | Core SDK (required) |
runanywhere_llamacpp | ~15-25MB | LLM text generation with GGUF models |
runanywhere_onnx | ~50-70MB | STT/TTS/VAD via ONNX Runtime |
Architecture
Starter Example
Flutter Starter Example
Complete working example with LLM chat, STT, TTS, and Voice Agent demos