Implementation:Microsoft Playwright BackendAdb

Knowledge Sources	Microsoft_Playwright
Domains	Android, ADB
Last Updated	2026-02-12 00:00 GMT

Overview

Concrete tool for communicating with Android devices over the Android Debug Bridge (ADB) protocol provided by the Playwright library.

Description

The `AdbBackend` class implements the `Backend` interface for discovering Android devices via ADB. It issues the `host:devices` command to enumerate connected devices, returning an array of `AdbDevice` instances. Each `AdbDevice` implements the `DeviceBackend` interface with methods for running shell commands (`runCommand`), opening TCP sockets (`open`), and managing device lifecycle (`init`, `close`). The module communicates directly with the ADB daemon over TCP sockets using the ADB wire protocol (4-byte hex length prefix).

Usage

Use BackendAdb when automating Android devices with Playwright's Android automation support, which requires an ADB server running on the specified host and port.

Code Reference

Source Location

• Repository: Microsoft_Playwright
• File: packages/playwright-core/src/server/android/backendAdb.ts

Signature

export class AdbBackend implements Backend {
  async devices(options?: channels.AndroidDevicesOptions): Promise<DeviceBackend[]>;
}

class AdbDevice implements DeviceBackend {
  serial: string;
  status: string;
  host: string | undefined;
  port: number | undefined;
  constructor(serial: string, status: string, host?: string, port?: number);
  async init(): Promise<void>;
  async close(): Promise<void>;
  runCommand(command: string): Promise<Buffer>;
  async open(command: string): Promise<SocketBackend>;
}

Import

import { AdbBackend } from '../server/android/backendAdb';

I/O Contract

Inputs

Name	Type	Required	Description
options.host	string	No	ADB server hostname (defaults to localhost)
options.port	number	No	ADB server port (defaults to 5037)
command	string	Yes	ADB shell command or transport command to execute

Outputs

Name	Type	Description
devices	DeviceBackend[]	Array of discovered Android device backends
result	Buffer	Raw command output buffer
socket	SocketBackend	Open TCP socket to the device

Usage Examples

import { AdbBackend } from '../server/android/backendAdb';

const backend = new AdbBackend();
const devices = await backend.devices({ host: 'localhost', port: 5037 });
for (const device of devices) {
  const output = await device.runCommand('shell:getprop ro.build.version.release');
  console.log(output.toString());
}

Related Pages

• Environment:Microsoft_Playwright_Node_Runtime_Environment