Error Monitoring Generator Skill

Error Monitoring Generator

Generates a production-ready error monitoring infrastructure with protocol-based architecture for easy provider swapping.

When This Skill Activates

User asks to "add crash reporting" or "error monitoring"
User mentions "Sentry", "Crashlytics", or "crash analytics"
User wants to "track errors in production"
User asks about "debugging production issues"

Pre-Generation Checks (CRITICAL)

1. Project Context Detection

Before generating, ALWAYS check:

# Check for existing crash reporting
rg -l "Sentry|Crashlytics|CrashReporter" --type swift

# Check Package.swift for existing SDKs
cat Package.swift | grep -i "sentry\|firebase\|crashlytics"

# Check for existing error handling patterns
rg "captureError|recordError|logError" --type swift | head -5

2. Conflict Detection

If existing crash reporting found:

Ask: Replace, wrap existing, or create parallel system?

Configuration Questions

Ask user via AskUserQuestion:

Initial provider?
- Sentry (recommended for indie devs)
- Firebase Crashlytics (if already using Firebase)
- None (set up infrastructure only)
Include breadcrumbs?
- Yes (track navigation, user actions)
- No (errors only)
Include user context?
- Yes (anonymized user ID, app state)
- No (minimal data collection)

Generation Process

Step 1: Create Core Files

Always generate:

Sources/ErrorMonitoring/
├── ErrorMonitoringService.swift     # Protocol
├── ErrorContext.swift               # Breadcrumbs, user info
└── NoOpErrorMonitoring.swift        # Testing/privacy

Based on provider selection:

Sources/ErrorMonitoring/Providers/
├── SentryErrorMonitoring.swift      # If Sentry selected
└── CrashlyticsErrorMonitoring.swift # If Crashlytics selected

Step 2: Read Templates

Read templates from this skill:

templates/ErrorMonitoringService.swift
templates/ErrorContext.swift
templates/NoOpErrorMonitoring.swift
templates/SentryErrorMonitoring.swift (if selected)
templates/CrashlyticsErrorMonitoring.swift (if selected)

Step 3: Customize for Project

Adapt templates to match:

Project naming conventions
Existing error types
Bundle identifier for Sentry DSN

Step 4: Integration

In App.swift:

import SwiftUI

@main
struct MyApp: App {
    init() {
        // Configure error monitoring
        ErrorMonitoring.shared.configure()
    }

    var body: some Scene {
        WindowGroup {
            ContentView()
                .environment(\.errorMonitoring, ErrorMonitoring.shared.service)
        }
    }
}

Capturing errors:

do {
    try await riskyOperation()
} catch {
    ErrorMonitoring.shared.service.captureError(error)
}

Adding breadcrumbs:

ErrorMonitoring.shared.service.addBreadcrumb(
    Breadcrumb(category: "navigation", message: "Opened settings")
)

Provider Setup

Sentry

Create account at sentry.io
Create project for iOS/macOS
Get DSN from Project Settings > Client Keys
Add to Package.swift:

.package(url: "https://github.com/getsentry/sentry-cocoa", from: "8.0.0")

Firebase Crashlytics

Add Firebase to your project via console.firebase.google.com
Download GoogleService-Info.plist
Add Firebase SDK via SPM or CocoaPods
Enable Crashlytics in Firebase console

Generated Code Patterns

Protocol (Stable Interface)

protocol ErrorMonitoringService: Sendable {
    func configure()
    func captureError(_ error: Error, context: ErrorContext?)
    func captureMessage(_ message: String, level: ErrorLevel)
    func addBreadcrumb(_ breadcrumb: Breadcrumb)
    func setUser(_ user: MonitoringUser?)
    func reset()
}

Swapping Providers

// In ErrorMonitoring.swift
final class ErrorMonitoring {
    static let shared = ErrorMonitoring()

    // Change this ONE line to swap providers:
    let service: ErrorMonitoringService = SentryErrorMonitoring()
    // let service: ErrorMonitoringService = CrashlyticsErrorMonitoring()
    // let service: ErrorMonitoringService = NoOpErrorMonitoring()
}

Breadcrumb Tracking

// Automatic navigation breadcrumbs
struct ContentView: View {
    @Environment(\.errorMonitoring) var errorMonitoring

    var body: some View {
        Button("Open Details") {
            errorMonitoring.addBreadcrumb(
                Breadcrumb(category: "ui", message: "Tapped details button")
            )
            showDetails = true
        }
    }
}

Verification Checklist

After generation, verify:

[ ] App compiles without errors
[ ] Provider SDK added (if applicable)
[ ] DSN/config set correctly
[ ] Test error appears in dashboard
[ ] Breadcrumbs captured correctly
[ ] User context (if enabled) shows in reports
[ ] NoOp mode works for debug/testing

Privacy Considerations

GDPR Compliance

Use NoOpErrorMonitoring for EU users who opt out
Don't capture PII in error messages
Anonymize user IDs

App Store Guidelines

Disclose crash reporting in privacy policy
Use App Tracking Transparency if combining with analytics
Don't capture unnecessary device identifiers

Privacy Manifest (iOS 17+)

Add to PrivacyInfo.xcprivacy if using Sentry/Crashlytics:

<key>NSPrivacyCollectedDataTypes</key>
<array>
    <dict>
        <key>NSPrivacyCollectedDataType</key>
        <string>NSPrivacyCollectedDataTypeCrashData</string>
        <key>NSPrivacyCollectedDataTypeLinked</key>
        <false/>
        <key>NSPrivacyCollectedDataTypeTracking</key>
        <false/>
        <key>NSPrivacyCollectedDataTypePurposes</key>
        <array>
            <string>NSPrivacyCollectedDataTypePurposeAppFunctionality</string>
        </array>
    </dict>
</array>

Common Customizations

Custom Error Types

enum AppError: Error {
    case networkFailure(URLError)
    case decodingFailure(DecodingError)
    case authenticationRequired

    var context: ErrorContext {
        ErrorContext(
            tags: ["error_type": String(describing: self)],
            extra: ["recoverable": isRecoverable]
        )
    }
}

// Capture with context
errorMonitoring.captureError(error, context: error.context)

Performance Monitoring

// Sentry supports performance monitoring
let transaction = SentrySDK.startTransaction(name: "Load Data", operation: "http")
defer { transaction.finish() }

let data = try await fetchData()

Release Tracking

// Include version info
SentrySDK.start { options in
    options.dsn = "YOUR_DSN"
    options.releaseName = "\(Bundle.main.appVersion)-\(Bundle.main.buildNumber)"
}

Agent Skills: Error Monitoring Generator

Install this agent skill to your local

Skill Files