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Settings Mutation

Programmatically change device state: brightness, ringer, airplane mode, bluetooth, any setting Android exposes.

High-Level Actions

adb(action="set_brightness", value=128)       # 0-255
adb(action="set_ringer", mode="silent")       # silent | vibrate | normal
adb(action="set_airplane_mode", enabled=True)
adb(action="set_bluetooth", enabled=False)

Low-Level Settings API

Android stores settings in three namespaces:

Namespace Purpose
global Device-wide (wifi, airplane, time)
system User prefs (brightness, volume, ringtone)
secure Security-sensitive (location, accessibility)

Get / Put / Delete

adb(action="setting_get", namespace="global", key="airplane_mode_on")
adb(action="setting_put", namespace="system", key="screen_brightness", value="128")
adb(action="setting_delete", namespace="secure", key="my_key")

List All in Namespace

adb(action="setting_list", namespace="global")
# → huge list of all global settings

Dump

adb(action="setting_dump", namespace="system")

Common Keys

Key Namespace Values
airplane_mode_on global 0 / 1
wifi_on global 0 / 1
bluetooth_on global 0 / 1
auto_time global 0 / 1
screen_brightness system 0–255
screen_brightness_mode system 0 manual, 1 auto
screen_off_timeout system milliseconds
vibrate_on system 0 / 1
notification_sound system URI
location_mode secure 0 off, 3 high accuracy
accessibility_enabled secure 0 / 1

Agent Recipes

"Going to sleep"

agent("""
airplane mode on, ringer silent, brightness 10%,
screen timeout 30s. I'm going to bed.
""")

"Meeting mode"

agent("ringer to vibrate, do-not-disturb on, keep wifi")

"Travel mode"

agent("enable airplane, then turn wifi back on for gate wifi")

"Dark room adaptation"

agent("""
if ambient light is below 5 lux,
drop brightness to 20 and enable dark theme.
""")

Permission Caveats

Some settings require extra permissions:

  • secure namespace may need WRITE_SECURE_SETTINGS granted via adb: 
    adb shell pm grant <pkg> android.permission.WRITE_SECURE_SETTINGS
  • Do Not Disturb requires a notification policy exception.
  • Default SMS/Dialer changes need user confirmation.

Most toggles in global and system work out of the box.

Safety

Settings mutation can soft-brick UX in rare cases (e.g. brightness=0 + auto-mode off = black screen). strands-adb ships:

  • Dry-run mode via dry_run=True on destructive actions
  • Reverse snapshots — setting_dump before + apply + diff after
# Snapshot
before = adb(action="setting_dump", namespace="system")

# Mutate
adb(action="set_brightness", value=10)

# Restore later
for key, value in before["settings"].items():
    adb(action="setting_put", namespace="system", key=key, value=value)

What's Next