bitnet_flutter_ai 0.1.0-beta.1

Run Microsoft BitNet b1.58 2B-4T locally on Android, iOS, desktop, and Web (WASM).

Changelog

All notable changes to bitnet_flutter_ai will be documented in this file.

This project adheres to Semantic Versioning. Pre-1.0.0 versions (0.x.x-beta.y) may introduce breaking changes between beta releases.

---

0.1.0-beta.1 — 2026-04-09

Beta release. The public API is functional but may change before the stable 1.0.0 release. SHA-256 pinning, pre-built native binaries, and the Web WASM artefact are not yet distributed via pub.dev — see the README for build instructions.

Added

• BitNetEngine — unified load / generate / cancelGeneration / dispose interface backed by a dedicated Isolate on native and dart:js_interop on Web.
• BitNetModel.bitnet2B4T — immutable const descriptor for Microsoft BitNet b1.58 2B-4T (I2_S GGUF, 4096-token context, ~745 MiB on-disk).
• ModelCache — downloads the GGUF from HuggingFace with resumable HTTP (Range header), SHA-256 post-download verification, and atomic rename to final path. Uses getApplicationSupportDirectory() via path_provider.
• DeviceInspector — platform-agnostic RAM gate (≥ 3072 MB required).
  • Android: ActivityManager.MemoryInfo.totalMem via MethodChannel.
  • iOS: ProcessInfo.processInfo.physicalMemory via MethodChannel.
  • macOS / Linux / Windows: system_info2 (SysInfo.getTotalPhysicalMemory()).
  • Web: navigator.deviceMemory (fails closed to 0 if unavailable).
• C bridge (native/bitnet_bridge.h + native/bitnet_bridge.cc) — thin C ABI wrapping the llama.cpp new C API: llama_model_load_from_file, llama_new_context_with_model, llama_decode, llama_sampler_chain_init, llama_token_to_piece, llama_token_is_eog.
• FFI bindings (lib/src/ffi/) — hand-authored ffigen-compatible bindings and NativeLibrary wrapper with using() / Arena pointer lifecycle management.
• web/coi_service_worker.js — COI shim that injects Cross-Origin-Opener-Policy: same-origin and Cross-Origin-Embedder-Policy: require-corp headers, enabling SharedArrayBuffer for WASM threads in Chrome and Firefox.
• Sealed exception hierarchy — BitNetException base with typed subclasses for every failure mode (device, platform, library, init, inference, hash mismatch, download, not-loaded, isolate).
• Unit tests — 12 tests covering BitNetModel metadata, DeviceInspector RAM thresholds, exception messages, and ModelCache download/resume/clear flows.

Known Limitations (beta)

• Pre-built native binaries (libbitnet_bridge.so, .dylib, .dll) are not yet bundled. Consumers must compile native/bitnet_bridge.cc against llama.cpp themselves. See Building Native Libraries.
• The WASM artefact (BitNetWasm JS object) is not yet published. Web support requires a custom Emscripten build.
• ggufSha256 is a placeholder sentinel — post-download hash verification is skipped until the hash is pinned after the first CI download.
• Windows and Linux desktop are untested in this release. Android and iOS are the primary targets.
• cancelGeneration() on Web cancels at the next yield boundary only (no interrupt signal to the synchronous WASM loop).