ios-android-logs

# List connected devices
xcrun devicectl list devices
 
# Stream logs from specific device
xcrun devicectl device log stream --device <DEVICE_UUID>
 
# Stream with predicate filter
xcrun devicectl device log stream --device <DEVICE_UUID> \
  --predicate 'process == "YourApp"'
 
# Stream specific log levels
xcrun devicectl device log stream --device <DEVICE_UUID> \
  --level error
 
# Save to file
xcrun devicectl device log stream --device <DEVICE_UUID> \
  --predicate 'process == "YourApp"' > app_logs.txt

# Stream logs from booted simulator
xcrun simctl spawn booted log stream
 
# Filter by process
xcrun simctl spawn booted log stream --predicate 'process == "YourApp"'
 
# Filter by subsystem
xcrun simctl spawn booted log stream --predicate 'subsystem == "com.yourapp"'
 
# Show only errors
xcrun simctl spawn booted log stream --level error
 
# Combine filters
xcrun simctl spawn booted log stream \
  --predicate 'process == "YourApp" AND messageType == error'

# Process name
--predicate 'process == "YourApp"'
 
# Contains text
--predicate 'eventMessage contains "error"'
 
# Subsystem
--predicate 'subsystem == "com.yourapp.plugin"'
 
# Category
--predicate 'category == "network"'
 
# Log level
--predicate 'messageType == error'
 
# Combined
--predicate 'process == "YourApp" AND messageType >= error'
 
# Time-based (last 5 minutes)
--predicate 'timestamp > now - 5m'

# Basic log stream
adb logcat
 
# Clear logs first, then stream
adb logcat -c && adb logcat
 
# Filter by tag
adb logcat -s MyTag:D
 
# Filter by priority
adb logcat *:E  # Only errors and above
 
# Filter by package name
adb logcat --pid=$(adb shell pidof com.yourapp.id)
 
# Filter by multiple tags
adb logcat -s "MyPlugin:D" "Capacitor:I"
 
# Save to file
adb logcat > logs.txt
 
# Save to file with timestamp
adb logcat -v time > logs.txt

# Install pidcat
pip install pidcat
 
# Stream logs for package
pidcat com.yourapp.id
 
# With tag filter
pidcat -t MyPlugin com.yourapp.id

# Different output formats
adb logcat -v brief     # Default
adb logcat -v process   # PID only
adb logcat -v tag       # Tag only
adb logcat -v time      # With timestamp
adb logcat -v threadtime # With thread and time
adb logcat -v long      # All metadata
 
# Colorized output
adb logcat -v color
 
# Show recent logs (last N lines)
adb logcat -d -t 100
 
# Show logs since timestamp
adb logcat -v time -T "01-25 10:00:00.000"

# Capacitor core logs
adb logcat -s "Capacitor:*"
 
# Plugin-specific logs
adb logcat -s "CapacitorNativeBiometric:*"
 
# WebView logs (JavaScript console)
adb logcat -s "chromium:*"
 
# JavaScript errors
adb logcat | grep -i "js error\|uncaught"
 
# Crash logs
adb logcat | grep -iE "fatal|crash|exception"
 
# Network logs
adb logcat -s "OkHttp:*" "NetworkSecurityConfig:*"

# Copy crash logs from device
xcrun devicectl device copy crashlog --device <UUID> ./crashes/
 
# View in Console.app
# User Diagnostics Reports section
 
# Or find at:
# Device: Settings > Privacy > Analytics & Improvements > Analytics Data
# Mac: ~/Library/Logs/DiagnosticReports/

# Get tombstone (native crash)
adb shell cat /data/tombstones/tombstone_00
 
# Get ANR traces
adb pull /data/anr/traces.txt
 
# Get bugreport (comprehensive)
adb bugreport > bugreport.zip

// Example MCP tool for fetching iOS logs
const logs = await mcp.ios.streamLogs({
  device: 'booted',
  predicate: 'process == "YourApp"',
  level: 'debug',
});
 
// Example MCP tool for Android logs
const androidLogs = await mcp.android.logcat({
  package: 'com.yourapp.id',
  level: 'D',
});

# iOS - JavaScript console logs
xcrun simctl spawn booted log stream \
  --predicate 'eventMessage contains "JS:"'
 
# Android - WebView console
adb logcat chromium:I *:S | grep "console"

# iOS
xcrun simctl spawn booted log stream \
  --predicate 'subsystem == "com.apple.network"'
 
# Android
adb logcat -s "NetworkSecurityConfig:*" "OkHttp:*"

# iOS - Memory pressure
xcrun simctl spawn booted log stream \
  --predicate 'eventMessage contains "memory"'
 
# Android - Memory info
adb shell dumpsys meminfo com.yourapp.id

# iOS - Only your app
--predicate 'process == "YourApp" AND messageType >= info'
 
# Android - Only your package
adb logcat --pid=$(adb shell pidof com.yourapp.id)

# Enable debug logs
xcrun simctl spawn booted log stream --level debug

Log.d("Tag", "Debug message")  // D level