FirmwareKit.Comm.ADB

A high-performance .NET implementation of the Android Debug Bridge (ADB) protocol over USB, strictly aligned with AOSP logic. Part of the FirmwareKit ecosystem.

Overview

Unlike the traditional Google adb client/server architecture, this library talks ADB directly to adbd — over USB (via FirmwareKit.Comm, like the fastboot implementation) or over TCP (AdbTcpTransport, equivalent to adb connect host:port). There is no adb server process, no host:5037 endpoint, and no adb.exe dependency. This makes it suitable for tools that need a self-contained, dependency-light ADB implementation for firmware flashing, factory automation, and device bring-up.

Architecture: direct-write (no client/server)

This project intentionally does not implement Google's client/server split. Every command opens its own transport to a device and speaks the ADB wire protocol directly to adbd:

┌──────────────┐    ADB wire protocol (CNXN/AUTH/OPEN/.../SYNC)    ┌──────┐
│ Library/CLI  │ ─────────────────────────────────────────────────▶│ adbd │
└──────────────┘          over USB or TCP (direct)                 └──────┘

Consequences of the direct-write design (vs. official adb):

Official adb feature	Direct-write behavior here
adb start-server / adb kill-server	Not applicable — no server to start or kill.
-H / -P point at the adb server (5037)	-H / -P point directly at an adbd endpoint (e.g. -H 127.0.0.1 -P 16416).
adb connect host:port registers the device with the server	connect validates the endpoint and stores it (see CLI below); every command then targets it directly.
adb forward (host-side listener)	Requires a persistent server process, so it is not supported in direct-write mode. Device-side reverse is supported (reverse: is handled by adbd itself).
adb devices lists everything the server knows	Lists USB devices found by enumeration, plus any endpoint saved via connect.

Self-contained transport layer

The transport layer is fully self-contained: it never shells out to an external adb binary, never connects to an adb server, and never proxies through a third process. Interaction with devices is performed by the library/CLI's own capabilities:

Transport	How it works
USB	UsbManager scans the host's USB ports directly (libusb / native API via FirmwareKit.Comm), claims the ADB interface (vendor class 0xFF, subclass 0x42, protocol 0x01), and performs raw bulk read/write on it.
TCP	AdbTcpTransport opens a native System.Net.Sockets.TcpClient straight to the device's adbd port (equivalent of adb connect host:port).
UDP	AdbMdnsDiscovery performs mDNS service discovery (_adb-tls-connect._tcp, _adb._tcp) with a native UdpClient multicast socket — the adb mdns services equivalent, without external tooling.

Features

• Direct, self-contained transports: USB (direct port scan + interface takeover + raw bulk I/O), TCP (native TcpClient), UDP (native UdpClient mDNS discovery). No external adb binary, no host:5037 server, no proxy process.
• Full ADB wire protocol: CNXN / AUTH / OPEN / OKAY / WRTE / CLSE / SYNC.
• RSA-SHA1 authentication with ADB-format public keys (2048-bit); reuses the user's ~/.android/adbkey when present.
• Stream multiplexing (AdbStream) over a single transport.
• Shell v2 protocol (shell,v2): stdout / stderr / exit code streaming, PTY and TERM support.
• Sync protocol (sync:): push / pull / stat / list (v1 wire format, which adbd accepts even when sendrecv_v2 is negotiated).
• Device services: reboot:, remount:, root:, unroot:, usb:, tcpip:, getprop.
• adb-compatible CLI (adb devices, adb shell, adb push, adb pull, ...) with matching parameters, interface, and return values.

Libraries

Project	Description
FirmwareKit.Comm.ADB	Core ADB protocol library (netstandard2.0 / net8.0 / net10.0).
FirmwareKit.Comm.ADB.Cli	adb-compatible command-line tool.
FirmwareKit.Comm.ADB.Tests	Unit tests for the protocol core.

USB backend selection

The library uses the platform native backend by default (WinUSB on Windows, usbfs on Linux, IOKit on macOS). The libusb-dotnet backend is available as an explicit opt-in — there is no automatic fallback:

• Library: set UsbManager.ForceLibUsb = true to force libusb.
• CLI: pass --libusb to use the libusb backend; without it, the native backend is used.

库默认使用平台原生后端（Windows 用 WinUSB、Linux 用 usbfs、macOS 用 IOKit）。libusb-dotnet 后端作为显式选项保留，不自动回退：库侧设置 为 true，CLI 侧传 --libusb。

Quick Start

using FirmwareKit.Comm.ADB;
using FirmwareKit.Comm.ADB.Backend.Usb;
using FirmwareKit.Comm.ADB.Protocol;
using FirmwareKit.Comm.ADB.Services;

// 1. Find a device (standard ADB USB interface).
var devices = UsbManager.GetAllDevices();
UsbDevice device = devices[0];

// 2. Connect and authenticate.
using var auth = AdbAuthentication.CreateNew();
using var connection = new AdbConnection(device, auth);
connection.Connect();

// 3. Run a shell command.
var shell = new AdbShellClient(connection, "getprop ro.product.model");
var result = shell.Execute();
Console.WriteLine(System.Text.Encoding.UTF8.GetString(result.Stdout));

CLI

adb devices          # list attached devices (native USB backend by default)
adb --libusb devices # list devices using the libusb backend instead
adb shell <cmd>      # run a remote command
adb push <l> <r>     # push a file
adb pull <r> [l]     # pull a file
adb reboot           # reboot the device
adb mdns services    # discover ADB devices on the LAN (native UDP mDNS)
adb version          # show version

Exit codes, parameters, and output formatting follow the stock adb tool.

License

MIT