Ios Android Logs

cap-go/capgo-skills/skills/ios-android-logs

by cap-go2cfb277a1488No license72 starsListed Oct 8, 2026Updated Oct 8, 2026Repository updated today

Guide to accessing device logs on iOS and Android for Capacitor apps. Covers command-line tools, GUI applications, filtering, and real-time streaming. Use this skill when users need to view device logs for debugging.

Instructions onlySoftware Development

AI-generated overview

Guide to viewing and filtering iOS and Android device logs for Capacitor app debugging.

What it does: This skill is a reference guide for accessing device logs on iOS and Android, aimed at Capacitor apps. It documents command-line tools such as xcrun devicectl, xcrun simctl and adb logcat, GUI options like Console.app and Android Studio Logcat, plus filtering, log levels, crash log retrieval and real-time streaming. It also lists troubleshooting steps and best practices, and shows example MCP calls for fetching logs programmatically.
When to use it: Use it when you need to view device logs, debug crashes, filter logs by app or package, or stream logs in real time. It is also useful when someone asks how to see logs on iOS or Android.
Requirements: Requires access to iOS and Android tooling: Xcode command-line tools (xcrun devicectl, xcrun simctl) and Android platform tools (adb), with a connected or simulated device. Optional tools mentioned include Console.app, Android Studio, Xcode, pidcat via pip, and MCP tools. No scripts are shipped; it is instructions only.

iOS and Android Device Logs

Complete guide to viewing and filtering device logs on iOS and Android.

When to Use This Skill

User needs to see device logs
User is debugging crashes
User wants to filter logs by app
User needs real-time log streaming
User asks "how to see logs"

Quick Commands

bash

# iOS - Stream logs from connected devicexcrun devicectl device log stream --device <UUID>
# iOS - Stream from simulatorxcrun simctl spawn booted log stream
# Android - Stream all logsadb logcat
# Android - Filter by packageadb logcat --pid=$(adb shell pidof com.yourapp.id)

# iOS - Stream logs from connected devicexcrun devicectl device log stream --device <UUID>
# iOS - Stream from simulatorxcrun simctl spawn booted log stream
# Android - Stream all logsadb logcat
# Android - Filter by packageadb logcat --pid=$(adb shell pidof com.yourapp.id)

iOS Logs

Method 1: Console.app (GUI)

Open Console.app (Applications > Utilities)
Select your device in sidebar
Click "Start Streaming"
Use search to filter:
- By process: process:YourApp
- By subsystem: subsystem:com.yourapp
- By message: "error"

Method 2: devicectl (CLI - Recommended)

bash

# List connected devicesxcrun devicectl list devices
# Stream logs from specific devicexcrun devicectl device log stream --device <DEVICE_UUID>
# Stream with predicate filterxcrun devicectl device log stream --device <DEVICE_UUID> \  --predicate 'process == "YourApp"'
# Stream specific log levelsxcrun devicectl device log stream --device <DEVICE_UUID> \  --level error
# Save to filexcrun devicectl device log stream --device <DEVICE_UUID> \  --predicate 'process == "YourApp"' > app_logs.txt

# List connected devicesxcrun devicectl list devices
# Stream logs from specific devicexcrun devicectl device log stream --device <DEVICE_UUID>
# Stream with predicate filterxcrun devicectl device log stream --device <DEVICE_UUID> \  --predicate 'process == "YourApp"'
# Stream specific log levelsxcrun devicectl device log stream --device <DEVICE_UUID> \  --level error
# Save to filexcrun devicectl device log stream --device <DEVICE_UUID> \  --predicate 'process == "YourApp"' > app_logs.txt

Method 3: simctl for Simulators

bash

# Stream logs from booted simulatorxcrun simctl spawn booted log stream
# Filter by processxcrun simctl spawn booted log stream --predicate 'process == "YourApp"'
# Filter by subsystemxcrun simctl spawn booted log stream --predicate 'subsystem == "com.yourapp"'
# Show only errorsxcrun simctl spawn booted log stream --level error
# Combine filtersxcrun simctl spawn booted log stream \  --predicate 'process == "YourApp" AND messageType == error'

# Stream logs from booted simulatorxcrun simctl spawn booted log stream
# Filter by processxcrun simctl spawn booted log stream --predicate 'process == "YourApp"'
# Filter by subsystemxcrun simctl spawn booted log stream --predicate 'subsystem == "com.yourapp"'
# Show only errorsxcrun simctl spawn booted log stream --level error
# Combine filtersxcrun simctl spawn booted log stream \  --predicate 'process == "YourApp" AND messageType == error'

Method 4: Xcode Device Logs

Window > Devices and Simulators
Select device
Click "Open Console"
Or: View device logs for crash reports

iOS Log Predicate Examples

bash

# 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'

# 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'

iOS Log Levels

Android Logs

Method 1: adb logcat (CLI)

bash

# Basic log streamadb logcat
# Clear logs first, then streamadb logcat -c && adb logcat
# Filter by tagadb logcat -s MyTag:D
# Filter by priorityadb logcat *:E  # Only errors and above
# Filter by package nameadb logcat --pid=$(adb shell pidof com.yourapp.id)
# Filter by multiple tagsadb logcat -s "MyPlugin:D" "Capacitor:I"
# Save to fileadb logcat > logs.txt
# Save to file with timestampadb logcat -v time > logs.txt

# Basic log streamadb logcat
# Clear logs first, then streamadb logcat -c && adb logcat
# Filter by tagadb logcat -s MyTag:D
# Filter by priorityadb logcat *:E  # Only errors and above
# Filter by package nameadb logcat --pid=$(adb shell pidof com.yourapp.id)
# Filter by multiple tagsadb logcat -s "MyPlugin:D" "Capacitor:I"
# Save to fileadb logcat > logs.txt
# Save to file with timestampadb logcat -v time > logs.txt

Method 2: Android Studio Logcat (GUI)

View > Tool Windows > Logcat
Use filter dropdown:
- Package: package:com.yourapp
- Tag: tag:MyPlugin
- Level: level:error
Create saved filters for quick access

Method 3: pidcat (Better CLI Tool)

bash

# Install pidcatpip install pidcat
# Stream logs for packagepidcat com.yourapp.id
# With tag filterpidcat -t MyPlugin com.yourapp.id

# Install pidcatpip install pidcat
# Stream logs for packagepidcat com.yourapp.id
# With tag filterpidcat -t MyPlugin com.yourapp.id

Android Log Priority Levels

adb logcat Format Options

bash

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

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

Common Android Filters

bash

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

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

Viewing Crash Logs

iOS Crash Logs

bash

# Copy crash logs from devicexcrun 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/

# Copy crash logs from devicexcrun 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/

Android Crash Logs

bash

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

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

MCP Integration

Use MCP tools to fetch logs programmatically:

typescript

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

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

Log Parsing Tips

Extract JavaScript Errors

bash

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

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

Filter Network Requests

bash

# iOSxcrun simctl spawn booted log stream \  --predicate 'subsystem == "com.apple.network"'
# Androidadb logcat -s "NetworkSecurityConfig:*" "OkHttp:*"

# iOSxcrun simctl spawn booted log stream \  --predicate 'subsystem == "com.apple.network"'
# Androidadb logcat -s "NetworkSecurityConfig:*" "OkHttp:*"

Monitor Memory

bash

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

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

Troubleshooting

Issue: No Logs Showing

iOS:

Ensure device is trusted: Xcode > Window > Devices
Try restarting log stream
Check Console.app filters

Android:

Enable USB debugging
Run adb devices to verify connection
Try adb kill-server && adb start-server

Issue: Too Many Logs

Use filters:

bash

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

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

Issue: Missing Debug Logs

iOS: Debug logs are hidden by default

Android: Ensure log level is set correctly

Best Practices

Use structured logging - Include context in log messages
Add timestamps - Helps correlate events
Filter early - Don't stream all logs
Save important logs - Redirect to file for later analysis
Use log levels appropriately - Debug for dev, error for production

Resources

iOS Unified Logging: https://developer.apple.com/documentation/os/logging
Android Logcat: https://developer.android.com/studio/debug/logcat
devicectl Reference: https://developer.apple.com/documentation/devicemanagement

Source and attribution

Source:cap-go/capgo-skillsinskills/ios-android-logsat commit2cfb277

License: No license

Content belongs to its original authors. SourceWeft indexes it from a public repository.

Report or request removal

Level	Description
`default`	Default messages
`info`	Informational
`debug`	Debug (hidden by default)
`error`	Error conditions
`fault`	Fault/critical

Letter	Priority
V	Verbose
D	Debug
I	Info
W	Warn
E	Error
F	Fatal
S	Silent

Ios Android Logs

iOS and Android Device Logs

When to Use This Skill

Quick Commands

iOS Logs

Method 1: Console.app (GUI)

Method 2: devicectl (CLI - Recommended)

Method 3: simctl for Simulators

Method 4: Xcode Device Logs

iOS Log Predicate Examples

iOS Log Levels

Android Logs

Method 1: adb logcat (CLI)

Method 2: Android Studio Logcat (GUI)

Method 3: pidcat (Better CLI Tool)

Android Log Priority Levels

adb logcat Format Options

Common Android Filters

Viewing Crash Logs

iOS Crash Logs

Android Crash Logs

MCP Integration

Log Parsing Tips

Extract JavaScript Errors

Filter Network Requests

Monitor Memory

Troubleshooting

Issue: No Logs Showing

Issue: Too Many Logs

Issue: Missing Debug Logs

Best Practices

Resources

Source and attribution

More from cap-go/capgo-skills

Webapp To Capacitor

Tailwind Capacitor

Safe Area Handling

Konsta Ui

Ionic Design

Debugging Capacitor

More in Software Development

Playground

M5 Onboard

Cardputer Buddy

Web Design Guidelines

Vercel React Native Skills

Vercel React Best Practices