---
name: android
description: Use when working with Android devices via ADB - connecting devices, running shell commands, installing apps, debugging, taking screenshots, UI automation, viewing logs, analyzing crashes, or exploring system internals. Triggers on "adb", "logcat", "install apk", "debug android", "android device", "shell command", "screenshot", "dumpsys", "crash", "ANR".
---

# Android Device Mastery

This skill covers everything about interacting with Android devices via ADB and shell commands.

## Device Connection

### Check Connected Devices

```bash
adb devices -l
```

Output shows serial, status, and device info. Common statuses:

- `device` - Connected and authorized
- `unauthorized` - Accept USB debugging prompt on device
- `offline` - Connection issues, try `adb kill-server && adb start-server`

### Wireless Debugging

**Android 11+ (Recommended):**

1. Enable Wireless debugging in Developer Options
2. Tap "Pair device with pairing code"
3. Run: `adb pair <ip>:<pairing_port>` and enter the code
4. Then: `adb connect <ip>:<connection_port>`

**Legacy (requires USB first):**

```bash
adb tcpip 5555
adb connect <device_ip>:5555
```

### Multiple Devices

Always specify device with `-s`:

```bash
adb -s <serial> shell
adb -s emulator-5554 install app.apk
```

---

## Shell Commands

### Interactive Shell

```bash
adb shell                    # Enter shell
adb shell <command>          # Run single command
adb shell "cmd1 && cmd2"     # Chain commands
```

### Essential Commands

```bash
# Device info
getprop ro.product.model              # Device model
getprop ro.build.version.release      # Android version
getprop ro.build.version.sdk          # SDK level

# File operations
ls -la /sdcard/
cat /path/to/file
cp /source /dest
rm /path/to/file

# Process info
ps -A | grep <name>
pidof <package_name>
top -n 1 -m 10
```

### Safe Output Limiting

For commands with potentially large output:

```bash
adb shell "logcat -d | head -500"
adb shell "dumpsys activity | head -200"
```

---

## App Management

### Install/Uninstall

```bash
adb install app.apk                   # Basic install
adb install -r app.apk                # Replace existing
adb install -g app.apk                # Grant all permissions
adb install -r -g app.apk             # Both

adb uninstall com.example.app         # Full uninstall
adb uninstall -k com.example.app      # Keep data
```

### Start/Stop Apps

```bash
# Start main activity
adb shell monkey -p com.example.app -c android.intent.category.LAUNCHER 1

# Start specific activity
adb shell am start -n com.example.app/.MainActivity

# Start with intent extras
adb shell am start -n com.example.app/.Activity \
    -a android.intent.action.VIEW \
    -d "myapp://page/123" \
    --es "key" "value"

# Force stop
adb shell am force-stop com.example.app

# Clear app data
adb shell pm clear com.example.app
```

### List Packages

```bash
adb shell pm list packages              # All packages
adb shell pm list packages -3           # Third-party only
adb shell pm list packages | grep term  # Filter

adb shell pm path com.example.app       # APK location
adb shell dumpsys package com.example.app  # Full package info
```

### Permissions

```bash
adb shell pm grant com.example.app android.permission.CAMERA
adb shell pm revoke com.example.app android.permission.CAMERA
adb shell dumpsys package com.example.app | grep permission
```

---

## File Operations

### Push/Pull Files

```bash
adb push local_file.txt /sdcard/
adb pull /sdcard/remote_file.txt ./

# Recursive
adb push local_dir/ /sdcard/target/
adb pull /sdcard/dir/ ./local/
```

### Access App Data (Debuggable Apps)

```bash
adb shell run-as com.example.app ls files/
adb shell run-as com.example.app cat shared_prefs/prefs.xml
adb shell run-as com.example.app sqlite3 databases/app.db ".tables"
```

---

## UI Automation

### Input Commands

```bash
# Tap at coordinates
adb shell input tap 500 800

# Swipe (x1 y1 x2 y2 [duration_ms])
adb shell input swipe 500 1500 500 500 300

# Text input (needs focused field)
adb shell input text "hello"

# Key events
adb shell input keyevent KEYCODE_HOME      # Home
adb shell input keyevent KEYCODE_BACK      # Back
adb shell input keyevent KEYCODE_ENTER     # Enter
adb shell input keyevent KEYCODE_POWER     # Power
adb shell input keyevent KEYCODE_VOLUME_UP # Volume up
```

### Common Keycodes

| Code | Key    | Code | Key      |
| ---- | ------ | ---- | -------- |
| 3    | HOME   | 4    | BACK     |
| 24   | VOL_UP | 25   | VOL_DOWN |
| 26   | POWER  | 66   | ENTER    |
| 67   | DEL    | 82   | MENU     |

### Screenshots & Recording

```bash
# Screenshot
adb shell screencap -p /sdcard/screen.png
adb pull /sdcard/screen.png

# One-liner (binary-safe)
adb exec-out screencap -p > screen.png

# Screen recording (max 3 min)
adb shell screenrecord /sdcard/video.mp4
adb shell screenrecord --time-limit 10 /sdcard/video.mp4
```

### UI Hierarchy

```bash
adb shell uiautomator dump /sdcard/ui.xml
adb pull /sdcard/ui.xml
```

---

## Debugging & Logs

### Logcat Essentials

```bash
# Dump and exit
adb logcat -d

# Last N lines
adb logcat -t 100

# Filter by tag:priority
adb logcat ActivityManager:I *:S

# Filter by package (get PID first)
adb logcat --pid=$(adb shell pidof -s com.example.app)

# Crash buffer
adb logcat -b crash
```

**Priority levels:** V(erbose), D(ebug), I(nfo), W(arn), E(rror), F(atal), S(ilent)

### Common Debug Patterns

```bash
# Find crashes
adb logcat *:E | grep -E "(Exception|Error|FATAL)"

# Activity lifecycle
adb logcat ActivityManager:I ActivityTaskManager:I *:S

# Memory issues
adb logcat art:D dalvikvm:D *:S | grep -i "gc"
```

### Memory Analysis

```bash
adb shell dumpsys meminfo com.example.app
```

Key metrics:

- **PSS**: Proportional memory use (compare apps with this)
- **Private Dirty**: Memory exclusive to process
- **Heap**: Java/Native heap usage

### Crash Analysis

```bash
# ANR traces
adb shell cat /data/anr/traces.txt

# Tombstones (native crashes, needs root)
adb shell ls /data/tombstones/

# Recent crashes via logcat
adb logcat -b crash -d
```

---

## System Inspection

### dumpsys Services

```bash
adb shell dumpsys -l                    # List all services

# Common services
adb shell dumpsys activity              # Activities, processes
adb shell dumpsys package <pkg>         # Package details
adb shell dumpsys battery               # Battery status
adb shell dumpsys meminfo               # System memory
adb shell dumpsys cpuinfo               # CPU usage
adb shell dumpsys window displays       # Display info
adb shell dumpsys connectivity          # Network state
```

### System Properties

```bash
adb shell getprop                       # All properties
adb shell getprop | grep <filter>       # Filter properties

# Useful properties
getprop ro.product.model                # Model
getprop ro.build.fingerprint            # Build fingerprint
getprop ro.serialno                     # Serial number
getprop sys.boot_completed              # Boot status (1 = done)
```

### Settings

```bash
# Namespaces: system, secure, global
adb shell settings get global airplane_mode_on
adb shell settings put system screen_brightness 128
adb shell settings list global
```

---

## Reboot Commands

```bash
adb reboot                   # Normal reboot
adb reboot recovery          # Recovery mode
adb reboot bootloader        # Fastboot mode
adb reboot sideload          # Sideload mode
adb reboot-bootloader        # Alias for bootloader
```

---

## Troubleshooting

**Device not found:**

```bash
adb kill-server && adb start-server
```

**Unauthorized:**

- Check USB debugging is enabled
- Revoke USB debugging authorizations in Developer Options, reconnect

**Multiple devices error:**

- Use `-s <serial>` to specify device

**Command not found (on device):**

- Some commands require root or are version-specific
- Try `/system/bin/<cmd>` or check if command exists

---

## Quick Reference

| Task         | Command                                                         |
| ------------ | --------------------------------------------------------------- |
| List devices | `adb devices -l`                                                |
| Install app  | `adb install -r -g app.apk`                                     |
| Start app    | `adb shell monkey -p pkg -c android.intent.category.LAUNCHER 1` |
| Stop app     | `adb shell am force-stop pkg`                                   |
| Screenshot   | `adb exec-out screencap -p > screen.png`                        |
| Logs         | `adb logcat -d -t 100`                                          |
| Shell        | `adb shell`                                                     |
| Push file    | `adb push local /sdcard/`                                       |
| Pull file    | `adb pull /sdcard/file ./`                                      |
| Tap          | `adb shell input tap X Y`                                       |
| Back         | `adb shell input keyevent 4`                                    |
| Home         | `adb shell input keyevent 3`                                    |

For deep dives into specific topics, see `references/deep-dive.md`.