ADB Phone Control#

Control Android devices through ADB with a structured observe-locate-act-verify loop.

Requirements#

• adb — Android Debug Bridge, must be in PATH
• python3 — Required for app_explorer.py
• ADB_OUTPUT_DIR (optional env var) — Directory for saving screenshots and UI dumps; defaults to current working directory

Permissions Used#

This skill executes the following on the connected Android device:

• adb shell input — tap, swipe, text input
• adb shell uiautomator dump — UI hierarchy extraction
• adb shell screencap — screen capture
• adb shell am broadcast — ADBKeyboard IME input (for CJK text)
• adb shell service call clipboard — clipboard-based text input fallback

Prerequisites#

Before any operation, verify device connection:

bash

adb devices

If no device found, instruct the user to:

1. Connect via USB and enable USB Debugging
2. Or connect wirelessly: adb connect <ip>:5555

Core Principle#

NEVER guess coordinates from screenshots. ALWAYS use UI hierarchy as the primary locator.

Screenshots are for human-readable context and visual verification. UI dumps give exact pixel bounds.

Operation Loop#

Every interaction follows this cycle:

text

┌─────────────────────────────────────────┐
│  1. OBSERVE  — dump UI + screenshot     │
│  2. LOCATE   — find element by text/id  │
│  3. ACT      — tap / swipe / type       │
│  4. VERIFY   — screenshot + dump again  │
│  5. REPEAT   — next action or done      │
└─────────────────────────────────────────┘

Do NOT skip the VERIFY step. UI transitions may take time; always confirm before proceeding.

Helper Functions#

Source the helper script before starting any operation session:

bash

source "$(dirname "${BASH_SOURCE[0]:-$0}")/adb-helpers.sh" 2>/dev/null || source ./adb-helpers.sh

Available Functions#

FunctionUsageDescriptionadb_dump``adb_dumpDump UI hierarchy to /tmp/ui_dump.xml``adb_screenshot``adb_screenshotCapture screen to /tmp/adb_screen.png``adb_observe``adb_observeDump UI + screenshot in one calladb_tap_text "Submit"Find element by text, tap centeradb_tap_id "btn_send"Find element by resource-id, tap centeradb_tap_xy 540 1200Tap exact coordinatesadb_swipe x1 y1 x2 y2 [ms]Swipe between points (default 300ms)adb_input_text "hello"Type text (supports spaces and CJK)adb_key <keycode>Send keyevent (BACK, HOME, ENTER, etc.)adb_hide_keyboardPress BACK to dismiss keyboardadb_scroll_downSwipe up to scroll content downadb_scroll_upSwipe down to scroll content upadb_long_press x y [ms]Long press at coordinates (default 1000ms)adb_wait [seconds]Sleep before next action (default 1s)adb_screen_sizeGet device screen resolutionadb_launch_app <package>Launch app by package nameadb_find_package <keyword>Search installed packages by keywordadb_bounds_center "bounds_string"Parse "[x1,y1][x2,y2]" → center x y

Element Lookup Details#

adb_tap_text and adb_tap_id work by:

1. Running adb_dump to get fresh UI hierarchy
2. Parsing the XML for matching text= or resource-id= attributes
3. Extracting the bounds="[x1,y1][x2,y2]" attribute
4. Computing center point: ((x1+x2)/2, (y1+y2)/2)
5. Executing adb shell input tap <cx> <cy>

If multiple matches are found, the function taps the first match and prints a warning. If no match is found, the function prints an error — fall back to adb_screenshot + Read tool for visual inspection.

Standard Operating Procedure#

Phase 1: Setup#

bash

# Source helpers
source "$(dirname "${BASH_SOURCE[0]:-$0}")/adb-helpers.sh" 2>/dev/null || source ./adb-helpers.sh

# Verify connection
adb devices

# Get screen resolution (important for swipe calculations)
adb_screen_size

Phase 2: Navigate & Operate#

For each interaction step:

bash

# 1. Observe current state
adb_observe
# Then read /tmp/adb_screen.png with the Read tool to see the screen

# 2. Locate and act (prefer text/id over raw coordinates)
adb_tap_text "Create"
# or: adb_tap_id "iv_send"
# or as last resort: adb_tap_xy 540 2009

# 3. Wait for transition
adb_wait 2

# 4. Verify result
adb_screenshot
# Then read /tmp/adb_screen.png to confirm the action worked

Phase 3: Text Input#

bash

# Tap the input field first
adb_tap_text "Search..."
adb_wait 1

# Type text
adb_input_text "Hello World"

# Hide keyboard before tapping other elements
adb_hide_keyboard
adb_wait 1

# Now safe to tap other buttons
adb_tap_text "Send"

Critical Rules#

1. UI Dump First, Screenshot Second#

• uiautomator dump gives exact bounds, element states (enabled/focused/clickable), text content, and resource IDs
• Screenshots only for: visual verification, understanding layout context, or when UI dump fails (e.g., animations, WebView content)
• When UI dump returns elements with NAF="true", the element has No Accessible Framework info — use screenshot + coordinates as fallback

2. Keyboard Awareness#

• Always hide keyboard before tapping non-input elements. The keyboard shifts the layout, making UI dump bounds stale.
• After typing, call adb_hide_keyboard then adb_dump before tapping anything else.
• If uiautomator dump returns ERROR: could not get idle state, the keyboard animation may still be running — wait 1s and retry.

3. Wait Strategy#

• After tap: wait 1s before next dump/screenshot
• After launching app: wait 2-3s
• After page navigation: wait 2s
• After typing: wait 0.5s
• If UI hasn't changed after action: wait longer, up to 5s, then re-check
• Never blindly chain actions without verification

4. Chinese / CJK Text Input#

adb shell input text does not support CJK characters natively. The helper adb_input_text handles this by:

• Using adb shell am broadcast with ADBKeyboard if available
• Falling back to clipboard-based input: copy to clipboard via adb shell service call clipboard, then paste

If ADB Keyboard IME is installed ( com.android.adbkeyboard), enable it:

bash

adb shell ime set com.android.adbkeyboard/.AdbIME

5. Coordinate System#

• All coordinates are in physical pixels matching the device resolution
• adb shell wm size returns the canonical resolution (e.g., 1080x2340)
• Screenshot pixel dimensions may differ from device resolution — never estimate coordinates from screenshot pixel positions
• Always derive coordinates from uiautomator dump bounds

6. Handling Failures#

If an action doesn't produce the expected result:

1. Re-dump UI hierarchy — the element may have moved or state changed
2. Take a screenshot — visual context may reveal popups, loading states, or errors
3. Check if the element is enabled="true" and clickable="true" before tapping
4. If element is not found by text, try partial match or search by resource-id
5. If the app is in a WebView, UI dump may not capture web elements — use screenshot + coordinate estimation as fallback

7. App Launch#

Prefer adb_find_package + adb_launch_app over monkey command:

bash

# Find the app
adb_find_package "wechat"
# Launch it
adb_launch_app "com.tencent.mm"

Limitations#

• uiautomator dump doesn't work during animations — wait for idle state
• WebView/Flutter/game content may not appear in UI hierarchy — use screenshot-based approach
• Some custom views may have empty text and no resource-id — use bounds + screenshot cross-reference
• Maximum ~100 actions per task is a reasonable limit to avoid infinite loops