Welcome to LocalSend

Chapter I

LocalSend is a cross-platform app for sending files and messages between nearby devices over HTTPS, with no internet or third-party server required. The repo is a polyglot monorepo: a Flutter app for the UI, a shared Dart package for discovery/transfer logic, a Rust crate implementing the wire protocol, a small Rust signaling relay for cross-network WebRTC, and a minimal CLI. Start in app/lib for the user-facing flow, then follow the FFI bridge into core/src to see the protocol itself.

LocalSend Architecture

Flutter App (UI)app/lib/main.dart

Shared Isolate/Task Layer…rent/parent_isolate_provider.dart

Device Discovery…work/nearby_devices_provider.dart

Embedded Receive Server…twork/server/server_provider.dart

CLI (cli/)cli/lib/main.dart

Send Session…ovider/network/send_provider.dart

Rust FFI Bridge (app/rust)app/lib/util/rust.dart

Core Protocol Crate (core/)core/src/http/server/mod.rs

Signaling Server (server/)server/src/main.rs

Figure I · Click a node to see what it does, where it lives in the code, and its labeled connections — the annotation opens beside it.