dart_libp2p_ble

Bluetooth LE transport (/ble) for dart-libp2p: phones and Macs nearby connect without a network. Each connection is one GATT link; libp2p secures it with Noise and multiplexes it with yamux, as on TCP.

Status: first release (0.1.0). Tested in memory (FakeBleNetwork) and on devices (Pixel 10a and iPhone: ping and gossipsub) with the test app in the repository's spike/. Platforms: Android, iOS, macOS.

Install

dependencies:
  dart_libp2p: ^4.10.0
  dart_libp2p_ble: ^0.1.0

Add the Bluetooth permissions (Android) and usage descriptions (iOS, macOS) that bluetooth_low_energy documents.

Usage

final ble = BleTransport(radio: BluetoothLowEnergyRadio(), localPeer: peerId);
final host = await Libp2p.new_([
  Libp2p.identity(keyPair),
  Libp2p.transport(ble),
  Libp2p.listenAddrs([ble.listenAddr]), // /ble/<token>
]);
await host.start();
final discovery = BleDiscovery(host: host, transport: ble);
await discovery.start(); // scans, and connects to nearby nodes

How it works

• Service: one GATT service with RX (central writes), TX (peripheral notifies) and an identity characteristic (the peer ID, read before dialing; Noise then proves it).
• Advertising: the service UUID and a 6-character token. iOS and macOS put the token in the local name (p2<token>); Android puts it in manufacturer data (company ID 0xFFFF, for tests), because the plugin can only set a name by renaming the phone.
• Addresses: /ble/<token>. A token is new each time the node starts; it means something only to devices nearby. Devices are found by token, never by platform peripheral ID, which changes.
• Framing: each GATT value starts with a type byte (data, close). The close frame exists because an iOS peripheral cannot disconnect a central.
• Discovery: every node scans and advertises; the lower token dials, the higher one dials after 8 s if no connection came. At most 4 links per node; gossipsub relays across the partial mesh.

Tests

flutter test