diff --git a/.DS_Store b/.DS_Store
index a6402b6..f49d40b 100644
Binary files a/.DS_Store and b/.DS_Store differ
diff --git a/SpotifyClone.xcodeproj/project.xcworkspace/xcuserdata/stephenchacha.xcuserdatad/UserInterfaceState.xcuserstate b/SpotifyClone.xcodeproj/project.xcworkspace/xcuserdata/stephenchacha.xcuserdatad/UserInterfaceState.xcuserstate
index 31563e6..b0e6bdc 100644
Binary files a/SpotifyClone.xcodeproj/project.xcworkspace/xcuserdata/stephenchacha.xcuserdatad/UserInterfaceState.xcuserstate and b/SpotifyClone.xcodeproj/project.xcworkspace/xcuserdata/stephenchacha.xcuserdatad/UserInterfaceState.xcuserstate differ
diff --git a/SpotifyClone/Core/Configuration/AppConfiguration.swift b/SpotifyClone/Core/Configuration/AppConfiguration.swift
new file mode 100644
index 0000000..66064c7
--- /dev/null
+++ b/SpotifyClone/Core/Configuration/AppConfiguration.swift
@@ -0,0 +1,69 @@
+//
+//  AppConfiguration.swift
+//  SpotifyClone
+//
+//  Created for code improvements
+//
+
+import Foundation
+
+/// Centralized configuration for the application
+enum AppConfiguration {
+    /// Spotify API configuration
+    enum Spotify {
+        static let baseURL = "https://api.spotify.com/v1"
+        static let authURL = "https://accounts.spotify.com"
+        static var tokenURL: String {
+            return "\(authURL)/api/token"
+        }
+        
+        static var clientID: String {
+            guard let path = Bundle.main.path(forResource: "Config", ofType: "plist"),
+                  let plist = NSDictionary(contentsOfFile: path) as? [String: Any],
+                  let id = plist["SpotifyClientID"] as? String, !id.isEmpty else {
+                fatalError("SpotifyClientID not found in Config.plist")
+            }
+            return id
+        }
+        
+        static var clientSecret: String {
+            guard let path = Bundle.main.path(forResource: "Config", ofType: "plist"),
+                  let plist = NSDictionary(contentsOfFile: path) as? [String: Any],
+                  let secret = plist["SpotifyClientSecret"] as? String, !secret.isEmpty else {
+                fatalError("SpotifyClientSecret not found in Config.plist")
+            }
+            return secret
+        }
+        
+        static var redirectURI: String {
+            guard let path = Bundle.main.path(forResource: "Config", ofType: "plist"),
+                  let plist = NSDictionary(contentsOfFile: path) as? [String: Any],
+                  let uri = plist["SpotifyRedirectURI"] as? String else {
+                return "http://localhost:3000/callback"
+            }
+            return uri
+        }
+    }
+    
+    /// UserDefaults keys
+    enum UserDefaultsKeys {
+        static let accessToken = "access_token"
+        static let refreshToken = "refresh_token"
+        static let expirationDate = "expiration_date"
+    }
+    
+    /// Cache configuration
+    enum Cache {
+        static let maxMemorySize = 50 * 1024 * 1024 // 50MB
+        static let maxDiskSize = 200 * 1024 * 1024 // 200MB
+        static let expirationInterval: TimeInterval = 3600 // 1 hour
+    }
+    
+    /// Network configuration
+    enum Network {
+        static let timeoutInterval: TimeInterval = 30
+        static let maxRetries = 3
+        static let retryBaseDelay: TimeInterval = 1.0
+    }
+}
+
diff --git a/SpotifyClone/Core/Error/ApiError.swift b/SpotifyClone/Core/Error/ApiError.swift
index 4e5a609..e372507 100644
--- a/SpotifyClone/Core/Error/ApiError.swift
+++ b/SpotifyClone/Core/Error/ApiError.swift
@@ -21,7 +21,7 @@ enum ApiError: LocalizedError {
     case apiError(String)
     case decodingError(String)
     case unknownError(String)
-    case rateLimitExceeded
+    case rateLimitExceeded(retryAfter: String? = nil)
     case jsonSerializationFailed
     case jsonParsingFailed
 
@@ -59,4 +59,68 @@ enum ApiError: LocalizedError {
             return "JSON parsing failed"
         }
     }
+    
+    /// User-friendly error message for display in UI
+    var userMessage: String {
+        switch self {
+        case .code:
+            return "Authentication failed. Please try logging in again."
+        case .tokenNotFound:
+            return "Your session has expired. Please log in again."
+        case .invalidInput:
+            return "Invalid input. Please check your search and try again."
+        case .invalidURL:
+            return "Something went wrong. Please try again."
+        case .failedToGetData:
+            return "Unable to load data. Please check your internet connection."
+        case .decodeError, .decodingError:
+            return "Unable to process the response. Please try again."
+        case .rateLimitExceeded(let retryAfter):
+            if let retryAfter = retryAfter, let seconds = Int(retryAfter) {
+                return "Too many requests. Please wait \(seconds) seconds and try again."
+            }
+            return "Too many requests. Please wait a moment and try again."
+        case .invalidResponse(let statusCode):
+            switch statusCode {
+            case 401:
+                return "Your session has expired. Please log in again."
+            case 403:
+                return "You don't have permission to access this."
+            case 404:
+                return "The requested item was not found."
+            case 429:
+                return "Too many requests. Please wait a moment."
+            case 500...599:
+                return "Server error. Please try again later."
+            default:
+                return "Something went wrong. Please try again."
+            }
+        case .noGenresAvailable:
+            return "No genres are currently available."
+        case .apiError(let message):
+            return "Error: \(message)"
+        case .encodingError(let message):
+            return "Encoding error: \(message)"
+        case .unknownError(let message):
+            return "An unexpected error occurred: \(message)"
+        case .jsonSerializationFailed, .jsonParsingFailed:
+            return "Unable to process the data. Please try again."
+        }
+    }
+    
+    /// Suggested recovery action for the error
+    var recoveryAction: String? {
+        switch self {
+        case .tokenNotFound, .code:
+            return "Log In"
+        case .failedToGetData:
+            return "Retry"
+        case .rateLimitExceeded:
+            return "Wait"
+        case .invalidResponse(let statusCode) where statusCode == 401:
+            return "Log In"
+        default:
+            return nil
+        }
+    }
 }
diff --git a/SpotifyClone/Core/Logging/Logger.swift b/SpotifyClone/Core/Logging/Logger.swift
new file mode 100644
index 0000000..9c56f0b
--- /dev/null
+++ b/SpotifyClone/Core/Logging/Logger.swift
@@ -0,0 +1,126 @@
+//
+//  Logger.swift
+//  SpotifyClone
+//
+//  Created for centralized logging
+//
+
+import Foundation
+import os.log
+
+/// Log levels for different types of messages
+enum LogLevel {
+    case debug
+    case info
+    case warning
+    case error
+    
+    var osLogType: OSLogType {
+        switch self {
+        case .debug: return .debug
+        case .info: return .info
+        case .warning: return .default
+        case .error: return .error
+        }
+    }
+    
+    var prefix: String {
+        switch self {
+        case .debug: return "🔍 DEBUG"
+        case .info: return "ℹ️ INFO"
+        case .warning: return "⚠️ WARNING"
+        case .error: return "❌ ERROR"
+        }
+    }
+}
+
+/// Centralized logging utility
+final class Logger {
+    static let shared = Logger()
+    
+    private let subsystem: String
+    private let category = "SpotifyClone"
+    private let log: OSLog
+    
+    #if DEBUG
+    private let isDebugMode = true
+    #else
+    private let isDebugMode = false
+    #endif
+    
+    private init() {
+        subsystem = Bundle.main.bundleIdentifier ?? "com.spotifyclone"
+        log = OSLog(subsystem: subsystem, category: category)
+    }
+    
+    /// Log a message with specified level
+    func log(
+        _ message: String,
+        level: LogLevel = .info,
+        file: String = #file,
+        function: String = #function,
+        line: Int = #line
+    ) {
+        let fileName = (file as NSString).lastPathComponent
+        let logMessage = "[\(fileName):\(line)] \(function) - \(message)"
+        
+        // Skip debug logs in release builds
+        if level == .debug && !isDebugMode {
+            return
+        }
+        
+        // Log to OSLog (visible in Console.app)
+        os_log("%{public}@", log: log, type: level.osLogType, logMessage)
+        
+        #if DEBUG
+        // Print to console in debug mode
+        print("\(level.prefix) - \(logMessage)")
+        #endif
+    }
+    
+    /// Log a debug message
+    func debug(
+        _ message: String,
+        file: String = #file,
+        function: String = #function,
+        line: Int = #line
+    ) {
+        log(message, level: .debug, file: file, function: function, line: line)
+    }
+    
+    /// Log an info message
+    func info(
+        _ message: String,
+        file: String = #file,
+        function: String = #function,
+        line: Int = #line
+    ) {
+        log(message, level: .info, file: file, function: function, line: line)
+    }
+    
+    /// Log a warning message
+    func warning(
+        _ message: String,
+        file: String = #file,
+        function: String = #function,
+        line: Int = #line
+    ) {
+        log(message, level: .warning, file: file, function: function, line: line)
+    }
+    
+    /// Log an error message
+    func error(
+        _ message: String,
+        error: Error? = nil,
+        file: String = #file,
+        function: String = #function,
+        line: Int = #line
+    ) {
+        var fullMessage = message
+        if let error = error {
+            fullMessage += " - Error: \(error.localizedDescription)"
+        }
+        log(fullMessage, level: .error, file: file, function: function, line: line)
+    }
+}
+
diff --git a/SpotifyClone/Core/Networking/NetworkMonitor.swift b/SpotifyClone/Core/Networking/NetworkMonitor.swift
new file mode 100644
index 0000000..9a436a5
--- /dev/null
+++ b/SpotifyClone/Core/Networking/NetworkMonitor.swift
@@ -0,0 +1,59 @@
+//
+//  NetworkMonitor.swift
+//  SpotifyClone
+//
+//  Created for network reachability monitoring
+//
+
+import Foundation
+import Network
+
+/// Delegate protocol for network status changes
+protocol NetworkMonitorDelegate: AnyObject {
+    func networkStatusChanged(isConnected: Bool)
+}
+
+/// Monitors network connectivity status
+final class NetworkMonitor {
+    static let shared = NetworkMonitor()
+    
+    private let monitor = NWPathMonitor()
+    private let queue = DispatchQueue(label: "com.spotifyclone.networkmonitor")
+    
+    /// Current network connection status
+    private(set) var isConnected: Bool = false
+    
+    /// Delegate to notify about network status changes
+    weak var delegate: NetworkMonitorDelegate?
+    
+    private init() {
+        startMonitoring()
+    }
+    
+    /// Start monitoring network connectivity
+    func startMonitoring() {
+        monitor.pathUpdateHandler = { [weak self] path in
+            let wasConnected = self?.isConnected ?? false
+            self?.isConnected = path.status == .satisfied
+            
+            // Notify delegate if status changed
+            if wasConnected != self?.isConnected {
+                DispatchQueue.main.async {
+                    self?.delegate?.networkStatusChanged(isConnected: self?.isConnected ?? false)
+                }
+            }
+        }
+        monitor.start(queue: queue)
+    }
+    
+    /// Stop monitoring network connectivity
+    func stopMonitoring() {
+        monitor.cancel()
+    }
+    
+    /// Check if network is currently available
+    func checkConnectivity() -> Bool {
+        return isConnected
+    }
+}
+
diff --git a/SpotifyClone/Extensions/UIViewController+ErrorDisplay.swift b/SpotifyClone/Extensions/UIViewController+ErrorDisplay.swift
new file mode 100644
index 0000000..80691bf
--- /dev/null
+++ b/SpotifyClone/Extensions/UIViewController+ErrorDisplay.swift
@@ -0,0 +1,46 @@
+//
+//  UIViewController+ErrorDisplay.swift
+//  SpotifyClone
+//
+//  Created for error display utilities
+//
+
+import UIKit
+
+extension UIViewController {
+    /// Display an error alert with user-friendly message
+    func showError(_ error: Error, title: String = "Error", completion: (() -> Void)? = nil) {
+        let message: String
+        let recoveryAction: String?
+        
+        if let apiError = error as? ApiError {
+            message = apiError.userMessage
+            recoveryAction = apiError.recoveryAction
+        } else {
+            message = error.localizedDescription
+            recoveryAction = nil
+        }
+        
+        let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)
+        
+        if let recoveryAction = recoveryAction {
+            alert.addAction(UIAlertAction(title: recoveryAction, style: .default) { _ in
+                completion?()
+            })
+        } else {
+            alert.addAction(UIAlertAction(title: "OK", style: .default) { _ in
+                completion?()
+            })
+        }
+        
+        present(alert, animated: true)
+    }
+    
+    /// Display a success message
+    func showSuccess(_ message: String, title: String = "Success") {
+        let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)
+        alert.addAction(UIAlertAction(title: "OK", style: .default))
+        present(alert, animated: true)
+    }
+}
+
diff --git a/SpotifyClone/Managers/AlbumApi.swift b/SpotifyClone/Managers/AlbumApi.swift
index 20d687a..131f3ff 100644
--- a/SpotifyClone/Managers/AlbumApi.swift
+++ b/SpotifyClone/Managers/AlbumApi.swift
@@ -5,7 +5,6 @@
 //  Created by stephen chacha on 25/12/2024.
 //
 import Foundation
-import UIKit
 
 final class AlbumApiCaller {
     static let shared = AlbumApiCaller()
@@ -251,22 +250,6 @@ final class AlbumApiCaller {
     }
     
     
-    // Helper function to get the top-most view controller
-    func topMostViewController() -> UIViewController? {
-        if let windowScene = UIApplication.shared.connectedScenes.first as? UIWindowScene,
-           let window = windowScene.windows.first(where: { $0.isKeyWindow }) {
-            var topController = window.rootViewController
-            
-            while let presentedVC = topController?.presentedViewController {
-                topController = presentedVC
-            }
-            
-            return topController
-        }
-        return nil
-    }
-    
-    
     // MARK: - Helper Methods
     private func createAndExecuteRequest<T: Decodable>(
         with url: URL?,
@@ -288,24 +271,16 @@ final class AlbumApiCaller {
                 }
                 
                 if let httpResponse = response as? HTTPURLResponse {
-                    print("Status Code: \(httpResponse.statusCode)")
+                    Logger.shared.debug("HTTP Status Code: \(httpResponse.statusCode)")
                     
                     if httpResponse.statusCode == 429 {
-                        if let retryAfterString = httpResponse.value(forHTTPHeaderField: "Retry-After"),
-                           let retryAfter = Double(retryAfterString) {
-                            print("Rate limit exceeded. Retrying after \(retryAfter) seconds.")
+                        let retryAfterString = httpResponse.value(forHTTPHeaderField: "Retry-After")
+                        let error = ApiError.rateLimitExceeded(retryAfter: retryAfterString)
+                        
+                        // If retry count allows and we have retry-after header, retry automatically
+                        if retryCount > 0, let retryAfterString = retryAfterString, let retryAfter = Double(retryAfterString) {
+                            Logger.shared.warning("Rate limit exceeded. Retrying after \(retryAfter) seconds.")
                             
-                            DispatchQueue.main.async {
-                                let alert = UIAlertController(
-                                    title: "Rate Limit Exceeded",
-                                    message: "Please wait for \(Int(retryAfter)) seconds before trying again.",
-                                    preferredStyle: .alert
-                                )
-                                alert.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
-                                if let viewController = self.topMostViewController() {
-                                    viewController.present(alert, animated: true, completion: nil)
-                                }
-                            }
                             DispatchQueue.global().asyncAfter(deadline: .now() + retryAfter) {
                                 self.createAndExecuteRequest(
                                     with: url,
@@ -315,6 +290,9 @@ final class AlbumApiCaller {
                                     completion: completion
                                 )
                             }
+                        } else {
+                            // No retries left or no retry-after header, return error
+                            completion(.failure(error))
                         }
                         return
                     }
@@ -324,17 +302,14 @@ final class AlbumApiCaller {
                     }
                 }
                 
-                // Debugging: Log raw data
-//                if let jsonString = String(data: data, encoding: .utf8) {
-//                    print("Response JSON: \(jsonString)")
-//                }
-//                
                 do {
                     let result = try JSONDecoder().decode(decodingType, from: data)
+                    Logger.shared.debug("Successfully decoded response")
                     completion(.success(result))
                 } catch {
                     if let responseString = String(data: data, encoding: .utf8) {
-                        print("Raw Response: \(responseString)")
+                        Logger.shared.error("Decoding error", error: error)
+                        Logger.shared.debug("Raw Response: \(responseString.prefix(500))")
                     }
                     completion(.failure(.decodingError(error.localizedDescription)))
                 }
diff --git a/SpotifyClone/Managers/AuthManager.swift b/SpotifyClone/Managers/AuthManager.swift
index c3de944..d8e8787 100644
--- a/SpotifyClone/Managers/AuthManager.swift
+++ b/SpotifyClone/Managers/AuthManager.swift
@@ -15,32 +15,20 @@ final class AuthManager {
     
     // MARK: - Constants
     struct Constants {
-        private static var config: [String: Any]? {
-            guard let path = Bundle.main.path(forResource: "Config", ofType: "plist"),
-                  let plist = NSDictionary(contentsOfFile: path) as? [String: Any] else {
-                fatalError("Config.plist not found. Please copy Config.example.plist to Config.plist and add your Spotify API credentials.")
-            }
-            return plist
-        }
-        
         static var clientID: String {
-            guard let id = config?["SpotifyClientID"] as? String, !id.isEmpty else {
-                fatalError("SpotifyClientID not found in Config.plist")
-            }
-            return id
+            return AppConfiguration.Spotify.clientID
         }
         
         static var clientSecret: String {
-            guard let secret = config?["SpotifyClientSecret"] as? String, !secret.isEmpty else {
-                fatalError("SpotifyClientSecret not found in Config.plist")
-            }
-            return secret
+            return AppConfiguration.Spotify.clientSecret
         }
         
-        static let tokenAPIURL = "https://accounts.spotify.com/api/token"
+        static var tokenAPIURL: String {
+            return AppConfiguration.Spotify.tokenURL
+        }
         
         static var redirectURI: String {
-            return config?["SpotifyRedirectURI"] as? String ?? "http://localhost:3000/callback"
+            return AppConfiguration.Spotify.redirectURI
         }
         
         static let rawScopes = [
@@ -83,15 +71,15 @@ final class AuthManager {
     
     // MARK: - Variables
     public var accessToken: String? {
-        return UserDefaults.standard.string(forKey: "access_token")
+        return UserDefaults.standard.string(forKey: AppConfiguration.UserDefaultsKeys.accessToken)
     }
     
     private var refreshToken: String? {
-        return UserDefaults.standard.string(forKey: "refresh_token")
+        return UserDefaults.standard.string(forKey: AppConfiguration.UserDefaultsKeys.refreshToken)
     }
     
     private var tokenExpirationDate: Date? {
-        return UserDefaults.standard.object(forKey: "expiration_date") as? Date
+        return UserDefaults.standard.object(forKey: AppConfiguration.UserDefaultsKeys.expirationDate) as? Date
     }
     
     private var shouldRefreshToken: Bool {
@@ -231,19 +219,19 @@ final class AuthManager {
     
     // MARK: - Cache Tokens
     private func cacheToken(result: AuthResponse) {
-        UserDefaults.standard.setValue(result.access_token, forKey: "access_token")
+        UserDefaults.standard.setValue(result.access_token, forKey: AppConfiguration.UserDefaultsKeys.accessToken)
         if let refreshToken = result.refresh_token {
-            UserDefaults.standard.setValue(refreshToken, forKey: "refresh_token")
+            UserDefaults.standard.setValue(refreshToken, forKey: AppConfiguration.UserDefaultsKeys.refreshToken)
         }
         let expirationDate = Date().addingTimeInterval(TimeInterval(result.expires_in))
-        UserDefaults.standard.setValue(expirationDate, forKey: "expiration_date")
+        UserDefaults.standard.setValue(expirationDate, forKey: AppConfiguration.UserDefaultsKeys.expirationDate)
     }
     
-    // MARK: - Cache Tokens
+    // MARK: - Sign Out
     public func signOut(completion: (Bool)->Void ) {
-        UserDefaults.standard.setValue(nil, forKey: "access_token")
-        UserDefaults.standard.setValue(nil, forKey: "refresh_token")
-        UserDefaults.standard.setValue(nil, forKey: "expiration_date")
+        UserDefaults.standard.setValue(nil, forKey: AppConfiguration.UserDefaultsKeys.accessToken)
+        UserDefaults.standard.setValue(nil, forKey: AppConfiguration.UserDefaultsKeys.refreshToken)
+        UserDefaults.standard.setValue(nil, forKey: AppConfiguration.UserDefaultsKeys.expirationDate)
         
         completion(true)
     }
diff --git a/SpotifyClone/Managers/ChapterApiCaller.swift b/SpotifyClone/Managers/ChapterApiCaller.swift
index 3c8f0e0..2e10ae2 100644
--- a/SpotifyClone/Managers/ChapterApiCaller.swift
+++ b/SpotifyClone/Managers/ChapterApiCaller.swift
@@ -7,7 +7,6 @@
 
 
 import Foundation
-import UIKit
 
 final class ChapterApiCaller {
     
@@ -84,23 +83,12 @@ final class ChapterApiCaller {
                     
                     // Handle Rate Limit Exceeded (429)
                     if httpResponse.statusCode == 429 {
-                        if let retryAfterString = httpResponse.value(forHTTPHeaderField: "Retry-After"),
-                           let retryAfter = Double(retryAfterString) {
-                            print("Rate limit exceeded. Retrying after \(retryAfter) seconds.")
-                            
-                            // Show feedback to the user that a wait is required
-                            DispatchQueue.main.async {
-                                let alert = UIAlertController(
-                                    title: "Rate Limit Exceeded",
-                                    message: "Please wait for \(Int(retryAfter)) seconds before trying again.",
-                                    preferredStyle: .alert
-                                )
-                                alert.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
-                                // Present alert to the user
-                                if let viewController = self.topMostViewController() {
-                                    viewController.present(alert, animated: true, completion: nil)
-                                }
-                            }
+                        let retryAfterString = httpResponse.value(forHTTPHeaderField: "Retry-After")
+                        let error = ApiError.rateLimitExceeded(retryAfter: retryAfterString)
+                        
+                        // If retry count allows and we have retry-after header, retry automatically
+                        if retryCount > 0, let retryAfterString = retryAfterString, let retryAfter = Double(retryAfterString) {
+                            Logger.shared.warning("Rate limit exceeded. Retrying after \(retryAfter) seconds.")
                             
                             // Wait before retrying based on Retry-After header
                             DispatchQueue.global().asyncAfter(deadline: .now() + retryAfter) {
@@ -112,6 +100,9 @@ final class ChapterApiCaller {
                                     completion: completion
                                 )
                             }
+                        } else {
+                            // No retries left or no retry-after header, return error
+                            completion(.failure(error))
                         }
                         return
                     }
@@ -122,18 +113,15 @@ final class ChapterApiCaller {
                     }
                 }
                 
-                // Debugging: Log raw data
-                if let jsonString = String(data: data, encoding: .utf8) {
-                    print("Response JSON: \(jsonString)")
-                }
-                
                 do {
                     let result = try JSONDecoder().decode(responseType, from: data)
+                    Logger.shared.debug("Successfully decoded response for endpoint: \(endpoint)")
                     completion(.success(result))
                 } catch {
                     // Log raw response for debugging
                     if let responseString = String(data: data, encoding: .utf8) {
-                        print("Raw Response: \(responseString)")
+                        Logger.shared.error("Decoding error for endpoint: \(endpoint)", error: error)
+                        Logger.shared.debug("Raw Response: \(responseString.prefix(500))")
                     }
                     completion(.failure(ApiError.decodingError(error.localizedDescription)))
                 }
@@ -142,23 +130,6 @@ final class ChapterApiCaller {
         }
     }
     
-    // Helper function to get the top-most view controller
-    func topMostViewController() -> UIViewController? {
-        if let windowScene = UIApplication.shared.connectedScenes.first as? UIWindowScene,
-           let window = windowScene.windows.first(where: { $0.isKeyWindow }) {
-            var topController = window.rootViewController
-            
-            while let presentedVC = topController?.presentedViewController {
-                topController = presentedVC
-            }
-            
-            return topController
-        }
-        return nil
-    }
-    
-    
-    
     // MARK: - Fetch Shows
     public func getSeveralShows(
         ids: [String],
diff --git a/SpotifyClone/Resources/Assets.xcassets/AppIcon.appiconset/icon-20@2x.png b/SpotifyClone/Resources/Assets.xcassets/AppIcon.appiconset/icon-20@2x.png
deleted file mode 100644
index 42e0187..0000000
Binary files a/SpotifyClone/Resources/Assets.xcassets/AppIcon.appiconset/icon-20@2x.png and /dev/null differ
diff --git a/SpotifyClone/Resources/Assets.xcassets/AppIcon.appiconset/icon-20@3x.png b/SpotifyClone/Resources/Assets.xcassets/AppIcon.appiconset/icon-20@3x.png
deleted file mode 100644
index 8b526ed..0000000
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diff --git a/docs/ACTION_ITEMS.md b/docs/ACTION_ITEMS.md
new file mode 100644
index 0000000..6202937
--- /dev/null
+++ b/docs/ACTION_ITEMS.md
@@ -0,0 +1,46 @@
+# Action Items - Priority Checklist
+
+## 🔴 Critical (Do First - This Week)
+
+- [ ] **Fix SpotifyAPIClient** - Verify it compiles and works correctly
+- [ ] **Remove UI code from API layer** - Remove `UIAlertController` from `ChapterApiCaller` and `AlbumApi`
+- [ ] **Migrate API managers to SpotifyAPIClient** - Start with `TrackApi`, `PlaylistApi`, `SearchApi`
+- [ ] **Fix token refresh race condition** - Improve `AuthManager.withValidToken`
+
+## 🟡 High Priority (Next 2 Weeks)
+
+- [ ] **Add unit tests** - Start with `AuthManager` and `SpotifyAPIClient` (target: 10 tests)
+- [ ] **Implement proper caching** - Enhance `DataCache` with expiration and image caching
+- [ ] **Add NetworkMonitor** - Check network availability before requests
+- [ ] **Standardize error handling** - Use `Result<T, Error>` everywhere
+- [ ] **Create AppConfiguration** - Centralize all constants and URLs
+
+## 🟢 Medium Priority (Next Month)
+
+- [ ] **Reorganize features** - Move to `Features/` structure
+- [ ] **Add dependency injection** - Create protocols for managers
+- [ ] **Add logging framework** - Replace `print()` statements
+- [ ] **Add SwiftLint** - Enforce code style
+- [ ] **Audit memory leaks** - Check all closures for retain cycles
+
+## 🔵 Features (Ongoing)
+
+- [ ] **Mini Player** - Persistent bottom player
+- [ ] **Queue Management** - View and manage playback queue
+- [ ] **Offline Downloads** - Download for offline playback
+- [ ] **Widget Support** - Home screen widgets
+
+## 📝 Quick Wins (Can do today)
+
+- [ ] Add SwiftLint configuration (30 min)
+- [ ] Create `AppConfiguration.swift` (1 hour)
+- [ ] Add basic `NetworkMonitor` (2 hours)
+- [ ] Write 3 unit tests for `AuthManager` (2 hours)
+- [ ] Remove UI code from `ChapterApiCaller` (30 min)
+
+---
+
+**Total Estimated Time for Critical Items**: ~16 hours
+**Total Estimated Time for High Priority**: ~40 hours
+**Total Estimated Time for Medium Priority**: ~60 hours
+
diff --git a/docs/CODE_IMPROVEMENTS_EXAMPLES.md b/docs/CODE_IMPROVEMENTS_EXAMPLES.md
new file mode 100644
index 0000000..b51f1b4
--- /dev/null
+++ b/docs/CODE_IMPROVEMENTS_EXAMPLES.md
@@ -0,0 +1,543 @@
+# Code Improvement Examples
+
+This document provides concrete code examples for implementing the recommended improvements.
+
+## 1. AppConfiguration (Centralized Constants)
+
+**File**: `SpotifyClone/Core/Configuration/AppConfiguration.swift`
+
+```swift
+import Foundation
+
+enum AppConfiguration {
+    enum Spotify {
+        static let baseURL = "https://api.spotify.com/v1"
+        static let authURL = "https://accounts.spotify.com"
+        static let tokenURL = "\(authURL)/api/token"
+        
+        static var clientID: String {
+            guard let path = Bundle.main.path(forResource: "Config", ofType: "plist"),
+                  let plist = NSDictionary(contentsOfFile: path) as? [String: Any],
+                  let id = plist["SpotifyClientID"] as? String, !id.isEmpty else {
+                fatalError("SpotifyClientID not found in Config.plist")
+            }
+            return id
+        }
+        
+        static var clientSecret: String {
+            guard let path = Bundle.main.path(forResource: "Config", ofType: "plist"),
+                  let plist = NSDictionary(contentsOfFile: path) as? [String: Any],
+                  let secret = plist["SpotifyClientSecret"] as? String, !secret.isEmpty else {
+                fatalError("SpotifyClientSecret not found in Config.plist")
+            }
+            return secret
+        }
+        
+        static var redirectURI: String {
+            guard let path = Bundle.main.path(forResource: "Config", ofType: "plist"),
+                  let plist = NSDictionary(contentsOfFile: path) as? [String: Any],
+                  let uri = plist["SpotifyRedirectURI"] as? String else {
+                return "http://localhost:3000/callback"
+            }
+            return uri
+        }
+    }
+    
+    enum UserDefaultsKeys {
+        static let accessToken = "access_token"
+        static let refreshToken = "refresh_token"
+        static let expirationDate = "expiration_date"
+    }
+    
+    enum Cache {
+        static let maxMemorySize = 50 * 1024 * 1024 // 50MB
+        static let maxDiskSize = 200 * 1024 * 1024 // 200MB
+        static let expirationInterval: TimeInterval = 3600 // 1 hour
+    }
+}
+```
+
+## 2. NetworkMonitor (Network Reachability)
+
+**File**: `SpotifyClone/Core/Networking/NetworkMonitor.swift`
+
+```swift
+import Foundation
+import Network
+
+protocol NetworkMonitorDelegate: AnyObject {
+    func networkStatusChanged(isConnected: Bool)
+}
+
+final class NetworkMonitor {
+    static let shared = NetworkMonitor()
+    
+    private let monitor = NWPathMonitor()
+    private let queue = DispatchQueue(label: "NetworkMonitor")
+    
+    private(set) var isConnected: Bool = false
+    weak var delegate: NetworkMonitorDelegate?
+    
+    private init() {
+        startMonitoring()
+    }
+    
+    func startMonitoring() {
+        monitor.pathUpdateHandler = { [weak self] path in
+            let wasConnected = self?.isConnected ?? false
+            self?.isConnected = path.status == .satisfied
+            
+            if wasConnected != self?.isConnected {
+                DispatchQueue.main.async {
+                    self?.delegate?.networkStatusChanged(isConnected: self?.isConnected ?? false)
+                }
+            }
+        }
+        monitor.start(queue: queue)
+    }
+    
+    func stopMonitoring() {
+        monitor.cancel()
+    }
+}
+```
+
+## 3. Enhanced DataCache with Expiration
+
+**File**: `SpotifyClone/Core/Cache/DataCache.swift`
+
+```swift
+import Foundation
+
+struct CachedItem<T: Codable> {
+    let data: T
+    let expirationDate: Date
+    
+    var isExpired: Bool {
+        Date() > expirationDate
+    }
+}
+
+final class DataCache {
+    static let shared = DataCache()
+    
+    private let memoryCache = NSCache<NSString, NSData>()
+    private let diskCacheURL: URL
+    private let fileManager = FileManager.default
+    
+    private init() {
+        // Configure memory cache
+        memoryCache.countLimit = 100
+        memoryCache.totalCostLimit = 50 * 1024 * 1024 // 50MB
+        
+        // Setup disk cache directory
+        let cacheDirectory = fileManager.urls(for: .cachesDirectory, in: .userDomainMask)[0]
+        diskCacheURL = cacheDirectory.appendingPathComponent("SpotifyCache")
+        
+        try? fileManager.createDirectory(at: diskCacheURL, withIntermediateDirectories: true)
+    }
+    
+    func cache<T: Codable>(_ item: T, forKey key: String, expirationInterval: TimeInterval = AppConfiguration.Cache.expirationInterval) {
+        let expirationDate = Date().addingTimeInterval(expirationInterval)
+        let cachedItem = CachedItem(data: item, expirationDate: expirationDate)
+        
+        // Memory cache
+        if let data = try? JSONEncoder().encode(cachedItem) {
+            memoryCache.setObject(data as NSData, forKey: key as NSString)
+        }
+        
+        // Disk cache
+        let fileURL = diskCacheURL.appendingPathComponent(key)
+        if let data = try? JSONEncoder().encode(cachedItem) {
+            try? data.write(to: fileURL)
+        }
+    }
+    
+    func retrieve<T: Codable>(_ type: T.Type, forKey key: String) -> T? {
+        // Check memory cache first
+        if let memoryData = memoryCache.object(forKey: key as NSString) as Data?,
+           let cachedItem = try? JSONDecoder().decode(CachedItem<T>.self, from: memoryData),
+           !cachedItem.isExpired {
+            return cachedItem.data
+        }
+        
+        // Check disk cache
+        let fileURL = diskCacheURL.appendingPathComponent(key)
+        if let diskData = try? Data(contentsOf: fileURL),
+           let cachedItem = try? JSONDecoder().decode(CachedItem<T>.self, from: diskData),
+           !cachedItem.isExpired {
+            // Restore to memory cache
+            memoryCache.setObject(diskData as NSData, forKey: key as NSString)
+            return cachedItem.data
+        }
+        
+        return nil
+    }
+    
+    func remove(forKey key: String) {
+        memoryCache.removeObject(forKey: key as NSString)
+        let fileURL = diskCacheURL.appendingPathComponent(key)
+        try? fileManager.removeItem(at: fileURL)
+    }
+    
+    func clearAll() {
+        memoryCache.removeAllObjects()
+        try? fileManager.removeItem(at: diskCacheURL)
+        try? fileManager.createDirectory(at: diskCacheURL, withIntermediateDirectories: true)
+    }
+}
+```
+
+## 4. Protocol-Based Dependency Injection
+
+**File**: `SpotifyClone/Core/Networking/AuthManagerProtocol.swift`
+
+```swift
+import Foundation
+
+protocol AuthManagerProtocol {
+    var isSignedIn: Bool { get }
+    var accessToken: String? { get }
+    var signInURL: URL? { get }
+    
+    func exchangeCodeForToken(code: String, completion: @escaping (Bool) -> Void)
+    func refreshAccessToken(completion: @escaping (Bool) -> Void)
+    func withValidToken(completion: @escaping (String) -> Void)
+    func signOut(completion: (Bool) -> Void)
+    func createRequest(with url: URL?, type: HTTPMethod, completion: @escaping (URLRequest) -> Void)
+}
+
+extension AuthManager: AuthManagerProtocol {}
+
+// In tests, create a mock:
+class MockAuthManager: AuthManagerProtocol {
+    var isSignedIn: Bool = true
+    var accessToken: String? = "mock_token"
+    var signInURL: URL? = URL(string: "https://example.com")
+    
+    func exchangeCodeForToken(code: String, completion: @escaping (Bool) -> Void) {
+        completion(true)
+    }
+    
+    func refreshAccessToken(completion: @escaping (Bool) -> Void) {
+        completion(true)
+    }
+    
+    func withValidToken(completion: @escaping (String) -> Void) {
+        completion("mock_token")
+    }
+    
+    func signOut(completion: (Bool) -> Void) {
+        completion(true)
+    }
+    
+    func createRequest(with url: URL?, type: HTTPMethod, completion: @escaping (URLRequest) -> Void) {
+        var request = URLRequest(url: url!)
+        request.setValue("Bearer mock_token", forHTTPHeaderField: "Authorization")
+        completion(request)
+    }
+}
+```
+
+## 5. Enhanced Error Handling with User Messages
+
+**File**: `SpotifyClone/Core/Error/UserFriendlyError.swift`
+
+```swift
+import Foundation
+
+extension ApiError {
+    var userMessage: String {
+        switch self {
+        case .code:
+            return "Authentication failed. Please try logging in again."
+        case .tokenNotFound:
+            return "Your session has expired. Please log in again."
+        case .invalidInput:
+            return "Invalid input. Please check your search and try again."
+        case .invalidURL:
+            return "Something went wrong. Please try again."
+        case .failedToGetData:
+            return "Unable to load data. Please check your internet connection."
+        case .decodeError:
+            return "Unable to process the response. Please try again."
+        case .rateLimitExceeded:
+            return "Too many requests. Please wait a moment and try again."
+        case .invalidResponse(let statusCode):
+            switch statusCode {
+            case 401:
+                return "Your session has expired. Please log in again."
+            case 403:
+                return "You don't have permission to access this."
+            case 404:
+                return "The requested item was not found."
+            case 429:
+                return "Too many requests. Please wait a moment."
+            case 500...599:
+                return "Server error. Please try again later."
+            default:
+                return "Something went wrong. Please try again."
+            }
+        default:
+            return "An unexpected error occurred. Please try again."
+        }
+    }
+    
+    var recoveryAction: String? {
+        switch self {
+        case .tokenNotFound, .code:
+            return "Log In"
+        case .failedToGetData:
+            return "Retry"
+        case .rateLimitExceeded:
+            return "Wait"
+        default:
+            return nil
+        }
+    }
+}
+```
+
+## 6. Logging Framework Wrapper
+
+**File**: `SpotifyClone/Core/Logging/Logger.swift`
+
+```swift
+import Foundation
+import os.log
+
+enum LogLevel {
+    case debug
+    case info
+    case warning
+    case error
+    
+    var osLogType: OSLogType {
+        switch self {
+        case .debug: return .debug
+        case .info: return .info
+        case .warning: return .default
+        case .error: return .error
+        }
+    }
+}
+
+final class Logger {
+    static let shared = Logger()
+    
+    private let subsystem = Bundle.main.bundleIdentifier ?? "com.spotifyclone"
+    private let category = "SpotifyClone"
+    private let log: OSLog
+    
+    #if DEBUG
+    private let isDebugMode = true
+    #else
+    private let isDebugMode = false
+    #endif
+    
+    private init() {
+        log = OSLog(subsystem: subsystem, category: category)
+    }
+    
+    func log(_ message: String, level: LogLevel = .info, file: String = #file, function: String = #function, line: Int = #line) {
+        let fileName = (file as NSString).lastPathComponent
+        let logMessage = "[\(fileName):\(line)] \(function) - \(message)"
+        
+        if level == .debug && !isDebugMode {
+            return // Skip debug logs in release
+        }
+        
+        os_log("%{public}@", log: log, type: level.osLogType, logMessage)
+        
+        #if DEBUG
+        print("\(level) - \(logMessage)")
+        #endif
+    }
+    
+    func debug(_ message: String, file: String = #file, function: String = #function, line: Int = #line) {
+        log(message, level: .debug, file: file, function: function, line: line)
+    }
+    
+    func info(_ message: String, file: String = #file, function: String = #function, line: Int = #line) {
+        log(message, level: .info, file: file, function: function, line: line)
+    }
+    
+    func warning(_ message: String, file: String = #file, function: String = #function, line: Int = #line) {
+        log(message, level: .warning, file: file, function: function, line: line)
+    }
+    
+    func error(_ message: String, error: Error? = nil, file: String = #file, function: String = #function, line: Int = #line) {
+        var fullMessage = message
+        if let error = error {
+            fullMessage += " - Error: \(error.localizedDescription)"
+        }
+        log(fullMessage, level: .error, file: file, function: function, line: line)
+    }
+}
+```
+
+## 7. Retry Strategy for API Calls
+
+**File**: `SpotifyClone/Core/Networking/RetryStrategy.swift`
+
+```swift
+import Foundation
+
+struct RetryConfiguration {
+    let maxRetries: Int
+    let baseDelay: TimeInterval
+    let maxDelay: TimeInterval
+    let multiplier: Double
+    
+    static let `default` = RetryConfiguration(
+        maxRetries: 3,
+        baseDelay: 1.0,
+        maxDelay: 30.0,
+        multiplier: 2.0
+    )
+}
+
+extension SpotifyAPIClient {
+    func sendWithRetry<T: Decodable>(
+        _ endpoint: Endpoint,
+        configuration: RetryConfiguration = .default,
+        decoder customDecoder: JSONDecoder? = nil,
+        completion: @escaping (Result<T, Error>) -> Void
+    ) {
+        send(endpoint, decoder: customDecoder) { [weak self] result in
+            switch result {
+            case .success:
+                completion(result)
+            case .failure(let error):
+                if let apiError = error as? ApiError,
+                   case .rateLimitExceeded = apiError,
+                   configuration.maxRetries > 0 {
+                    // Retry with exponential backoff
+                    let delay = min(
+                        configuration.baseDelay * pow(configuration.multiplier, Double(configuration.maxRetries)),
+                        configuration.maxDelay
+                    )
+                    
+                    DispatchQueue.global().asyncAfter(deadline: .now() + delay) {
+                        var newConfig = configuration
+                        newConfig = RetryConfiguration(
+                            maxRetries: configuration.maxRetries - 1,
+                            baseDelay: configuration.baseDelay,
+                            maxDelay: configuration.maxDelay,
+                            multiplier: configuration.multiplier
+                        )
+                        self?.sendWithRetry(endpoint, configuration: newConfig, decoder: customDecoder, completion: completion)
+                    }
+                } else {
+                    completion(result)
+                }
+            }
+        }
+    }
+}
+```
+
+## 8. Example Unit Test
+
+**File**: `SpotifyCloneTests/AuthManagerTests.swift`
+
+```swift
+import XCTest
+@testable import SpotifyClone
+
+final class AuthManagerTests: XCTestCase {
+    var authManager: AuthManager!
+    var mockUserDefaults: UserDefaults!
+    
+    override func setUp() {
+        super.setUp()
+        mockUserDefaults = UserDefaults(suiteName: "test")!
+        // Use dependency injection if possible, or test the singleton
+        authManager = AuthManager.shared
+    }
+    
+    override func tearDown() {
+        mockUserDefaults.removePersistentDomain(forName: "test")
+        super.tearDown()
+    }
+    
+    func testIsSignedIn_WithValidToken_ReturnsTrue() {
+        // Given
+        mockUserDefaults.set("test_token", forKey: "access_token")
+        
+        // When
+        let isSignedIn = authManager.isSignedIn
+        
+        // Then
+        XCTAssertTrue(isSignedIn)
+    }
+    
+    func testIsSignedIn_WithoutToken_ReturnsFalse() {
+        // Given
+        mockUserDefaults.removeObject(forKey: "access_token")
+        
+        // When
+        let isSignedIn = authManager.isSignedIn
+        
+        // Then
+        XCTAssertFalse(isSignedIn)
+    }
+    
+    func testShouldRefreshToken_WhenExpired_ReturnsTrue() {
+        // Given
+        let expiredDate = Date().addingTimeInterval(-600) // 10 minutes ago
+        mockUserDefaults.set(expiredDate, forKey: "expiration_date")
+        
+        // When
+        // Note: This requires exposing shouldRefreshToken or testing indirectly
+        // through withValidToken
+        
+        // Then
+        // Assert expected behavior
+    }
+}
+```
+
+## 9. Removing UI from API Layer
+
+**Before** (ChapterApiCaller.swift):
+```swift
+if httpResponse.statusCode == 429 {
+    DispatchQueue.main.async {
+        let alert = UIAlertController(...)
+        viewController.present(alert, animated: true)
+    }
+}
+```
+
+**After**:
+```swift
+if httpResponse.statusCode == 429 {
+    if let retryAfter = httpResponse.value(forHTTPHeaderField: "Retry-After") {
+        let error = ApiError.rateLimitExceeded(retryAfter: retryAfter)
+        completion(.failure(error))
+        return
+    }
+}
+```
+
+Then handle in ViewController:
+```swift
+apiCaller.fetch(...) { result in
+    switch result {
+    case .success(let data):
+        // Handle success
+    case .failure(let error):
+        if case ApiError.rateLimitExceeded(let retryAfter) = error {
+            self.showRateLimitAlert(retryAfter: retryAfter)
+        } else {
+            self.showError(error)
+        }
+    }
+}
+```
+
+---
+
+These examples provide concrete patterns you can follow to implement the recommended improvements. Start with the critical items and work your way through the priority list.
+
diff --git a/docs/IMPLEMENTATION_SUMMARY.md b/docs/IMPLEMENTATION_SUMMARY.md
new file mode 100644
index 0000000..7897590
--- /dev/null
+++ b/docs/IMPLEMENTATION_SUMMARY.md
@@ -0,0 +1,231 @@
+# Implementation Summary - High Priority Improvements
+
+## ✅ Completed Improvements
+
+### 1. **AppConfiguration** - Centralized Constants
+**File**: `Core/Configuration/AppConfiguration.swift`
+
+- ✅ Created centralized configuration enum
+- ✅ Moved Spotify API credentials to AppConfiguration
+- ✅ Added UserDefaults keys constants
+- ✅ Added Cache configuration constants
+- ✅ Added Network configuration constants
+
+**Benefits**:
+- Single source of truth for all constants
+- Easier to maintain and update
+- Type-safe configuration access
+
+### 2. **NetworkMonitor** - Network Reachability
+**File**: `Core/Networking/NetworkMonitor.swift`
+
+- ✅ Implemented network monitoring using Network framework
+- ✅ Added delegate pattern for status changes
+- ✅ Provides real-time connectivity status
+
+**Benefits**:
+- Can check network before making requests
+- Notify users when offline
+- Better error handling for network issues
+
+### 3. **Logger** - Centralized Logging
+**File**: `Core/Logging/Logger.swift`
+
+- ✅ Replaced `print()` statements with proper logging
+- ✅ Added log levels (debug, info, warning, error)
+- ✅ Integrated with OSLog for Console.app visibility
+- ✅ Conditional compilation for debug vs release
+
+**Benefits**:
+- Better debugging experience
+- No performance impact in release builds
+- Structured logging for production
+
+### 4. **Enhanced ApiError** - User-Friendly Errors
+**File**: `Core/Error/ApiError.swift`
+
+- ✅ Added `userMessage` property for UI display
+- ✅ Added `recoveryAction` property for suggested actions
+- ✅ Enhanced `rateLimitExceeded` to include retry-after info
+- ✅ Better error messages for all error types
+
+**Benefits**:
+- Users see friendly error messages
+- Clear recovery actions
+- Better error handling in UI
+
+### 5. **Removed UI from API Layer**
+**Files**: 
+- `Managers/ChapterApiCaller.swift`
+- `Managers/AlbumApi.swift`
+
+- ✅ Removed `UIAlertController` from API managers
+- ✅ Removed `topMostViewController()` helper methods
+- ✅ Removed UIKit import from API layer
+- ✅ Replaced with proper error propagation
+- ✅ Added Logger calls instead of print statements
+
+**Benefits**:
+- Clean separation of concerns
+- API layer is now testable
+- No UIKit dependencies in networking code
+
+### 6. **Error Display Extension**
+**File**: `Extensions/UIViewController+ErrorDisplay.swift`
+
+- ✅ Created reusable error display method
+- ✅ Automatically uses user-friendly messages
+- ✅ Shows recovery actions when available
+
+**Benefits**:
+- Consistent error display across app
+- Easy to use: `viewController.showError(error)`
+- Better user experience
+
+### 7. **Updated AuthManager**
+**File**: `Managers/AuthManager.swift`
+
+- ✅ Refactored to use `AppConfiguration` constants
+- ✅ Updated UserDefaults keys to use constants
+- ✅ Cleaner code structure
+
+**Benefits**:
+- Consistent with new architecture
+- Easier to maintain
+- Type-safe key access
+
+---
+
+## 📊 Impact
+
+### Code Quality
+- ✅ **Separation of Concerns**: API layer no longer depends on UIKit
+- ✅ **Maintainability**: Centralized configuration and logging
+- ✅ **Testability**: API managers can now be unit tested
+- ✅ **Consistency**: Standardized error handling
+
+### User Experience
+- ✅ **Better Error Messages**: Users see friendly, actionable errors
+- ✅ **Network Awareness**: Can detect and handle offline scenarios
+- ✅ **Consistent UI**: Standardized error display across app
+
+### Developer Experience
+- ✅ **Better Debugging**: Structured logging with levels
+- ✅ **Easier Maintenance**: Centralized constants
+- ✅ **Cleaner Code**: Removed UI dependencies from API layer
+
+---
+
+## 🔄 Migration Guide
+
+### Using the New Components
+
+#### 1. Display Errors in ViewControllers
+```swift
+// Old way (removed from API layer)
+// API would show alert directly
+
+// New way
+apiCaller.fetchData { result in
+    switch result {
+    case .success(let data):
+        // Handle success
+    case .failure(let error):
+        self.showError(error) // Uses new extension
+    }
+}
+```
+
+#### 2. Using Logger
+```swift
+// Old way
+print("Status Code: \(statusCode)")
+
+// New way
+Logger.shared.info("Status Code: \(statusCode)")
+Logger.shared.error("API call failed", error: error)
+Logger.shared.debug("Response data: \(data)")
+```
+
+#### 3. Using AppConfiguration
+```swift
+// Old way
+let url = "https://api.spotify.com/v1/artists"
+let token = UserDefaults.standard.string(forKey: "access_token")
+
+// New way
+let url = AppConfiguration.Spotify.baseURL + "/artists"
+let token = UserDefaults.standard.string(forKey: AppConfiguration.UserDefaultsKeys.accessToken)
+```
+
+#### 4. Checking Network Status
+```swift
+// Check if network is available
+if NetworkMonitor.shared.isConnected {
+    // Make API call
+} else {
+    showError(ApiError.failedToGetData)
+}
+
+// Listen for network changes
+NetworkMonitor.shared.delegate = self
+
+func networkStatusChanged(isConnected: Bool) {
+    if isConnected {
+        // Retry failed requests
+    }
+}
+```
+
+---
+
+## 🚀 Next Steps
+
+### Immediate (Can do now)
+1. **Update remaining API managers** to use Logger instead of print
+2. **Add NetworkMonitor checks** before API calls
+3. **Use showError()** in ViewControllers for error display
+4. **Migrate more API managers** to SpotifyAPIClient pattern
+
+### Short Term (This week)
+1. **Migrate TrackApi** to use SpotifyAPIClient (example pattern)
+2. **Add unit tests** for new components (Logger, NetworkMonitor)
+3. **Update all ViewControllers** to use new error display
+4. **Add network status indicator** in UI
+
+### Medium Term (Next 2 weeks)
+1. **Migrate all API managers** to SpotifyAPIClient
+2. **Implement comprehensive caching** with expiration
+3. **Add retry strategy** to SpotifyAPIClient
+4. **Create protocol-based dependency injection**
+
+---
+
+## 📝 Files Changed
+
+### New Files Created
+- `Core/Configuration/AppConfiguration.swift`
+- `Core/Networking/NetworkMonitor.swift`
+- `Core/Logging/Logger.swift`
+- `Extensions/UIViewController+ErrorDisplay.swift`
+
+### Files Modified
+- `Core/Error/ApiError.swift` - Added user messages and recovery actions
+- `Managers/AuthManager.swift` - Updated to use AppConfiguration
+- `Managers/ChapterApiCaller.swift` - Removed UI code, added Logger
+- `Managers/AlbumApi.swift` - Removed UI code, added Logger
+
+---
+
+## ✨ Key Achievements
+
+1. **Architecture**: Clean separation between API and UI layers
+2. **Maintainability**: Centralized configuration and logging
+3. **User Experience**: Better error messages and network awareness
+4. **Code Quality**: Removed dependencies, improved testability
+5. **Developer Experience**: Better debugging tools and consistent patterns
+
+---
+
+*Implementation completed: January 2025*
+
diff --git a/docs/LibraryEndpoints.kt b/docs/LibraryEndpoints.kt
new file mode 100644
index 0000000..5151d96
--- /dev/null
+++ b/docs/LibraryEndpoints.kt
@@ -0,0 +1,356 @@
+// Library API Endpoints, Models, and DTOs in Kotlin
+// Based on SpotifyClone iOS project
+
+package com.spotifyclone.api.library
+
+import com.google.gson.annotations.SerializedName
+import io.ktor.client.HttpClient
+import io.ktor.client.call.body
+import io.ktor.client.request.get
+import io.ktor.client.request.header
+
+// ============================================================================
+// API ENDPOINTS
+// ============================================================================
+
+object LibraryEndpoints {
+    const val BASE_URL = "https://api.spotify.com/v1"
+    
+    // Get User's Saved Albums
+    const val GET_USER_SAVED_ALBUMS = "$BASE_URL/me/albums"
+    
+    // Get Current User's Playlists
+    const val GET_CURRENT_USER_PLAYLISTS = "$BASE_URL/me/playlists"
+    
+    // Get User's Saved Podcasts/Shows
+    const val GET_USER_SAVED_SHOWS = "$BASE_URL/me/shows"
+    
+    // Get User's Saved Episodes
+    const val GET_USER_SAVED_EPISODES = "$BASE_URL/me/episodes"
+}
+
+// ============================================================================
+// API SERVICE
+// ============================================================================
+
+class LibraryApiService(
+    private val client: HttpClient,
+    private val baseUrl: String = LibraryEndpoints.BASE_URL
+) {
+    /**
+     * Get User's Saved Albums
+     * GET /me/albums
+     */
+    suspend fun getUserSavedAlbums(
+        accessToken: String
+    ): SpotifyUsersAlbumSavedResponse {
+        return client.get("$baseUrl/me/albums") {
+            header("Authorization", "Bearer $accessToken")
+        }.body()
+    }
+
+    /**
+     * Get Current User's Playlists
+     * GET /me/playlists
+     */
+    suspend fun getCurrentUserPlaylists(
+        accessToken: String
+    ): CurrentUsersPlaylistsResponse {
+        return client.get("$baseUrl/me/playlists") {
+            header("Authorization", "Bearer $accessToken")
+        }.body()
+    }
+
+    /**
+     * Get User's Saved Podcasts/Shows
+     * GET /me/shows
+     */
+    suspend fun getUserSavedShows(
+        accessToken: String
+    ): UsersSavedShows {
+        return client.get("$baseUrl/me/shows") {
+            header("Authorization", "Bearer $accessToken")
+        }.body()
+    }
+
+    /**
+     * Get User's Saved Episodes
+     * GET /me/episodes
+     */
+    suspend fun getUserSavedEpisodes(
+        accessToken: String
+    ): UserSavedEpisodesResponse {
+        return client.get("$baseUrl/me/episodes") {
+            header("Authorization", "Bearer $accessToken")
+        }.body()
+    }
+}
+
+// ============================================================================
+// RESPONSE DTOs
+// ============================================================================
+
+// MARK: - Get User's Saved Albums Response
+data class SpotifyUsersAlbumSavedResponse(
+    val href: String?,
+    val items: List<SpotifyUsersAlbumSavedItemResponse>,
+    val limit: Int?,
+    val next: String?,
+    val offset: Int?,
+    val previous: String?,
+    val total: Int?
+)
+
+data class SpotifyUsersAlbumSavedItemResponse(
+    @SerializedName("added_at")
+    val addedAt: String,
+    val album: Album?
+)
+
+// MARK: - Get Current User's Playlists Response
+data class CurrentUsersPlaylistsResponse(
+    val href: String?,
+    val limit: Int?,
+    val next: String?,
+    val offset: Int?,
+    val previous: String?,
+    val total: Int?,
+    val items: List<PlaylistItem>?
+)
+
+// MARK: - Get User's Saved Shows/Podcasts Response
+data class UsersSavedShows(
+    val href: String,
+    val limit: Int,
+    val next: String?,
+    val offset: Int,
+    val previous: String?,
+    val total: Int?,
+    val items: List<UsersSavedShowsItems>?
+)
+
+data class UsersSavedShowsItems(
+    @SerializedName("added_at")
+    val addedAt: String,
+    val show: Show
+)
+
+// MARK: - Get User's Saved Episodes Response
+data class UserSavedEpisodesResponse(
+    val href: String?,
+    val limit: Int?,
+    val next: String?,
+    val offset: Int?,
+    val previous: String?,
+    val total: Int?,
+    val items: List<UserSavedEpisode>?
+)
+
+data class UserSavedEpisode(
+    @SerializedName("added_at")
+    val addedAt: String?,
+    val episode: Episode?
+)
+
+// ============================================================================
+// MODEL CLASSES
+// ============================================================================
+
+// MARK: - Album Model
+data class Album(
+    @SerializedName("album_type")
+    val albumType: String?,
+    @SerializedName("total_tracks")
+    val totalTracks: Int?,
+    @SerializedName("available_markets")
+    val availableMarkets: List<String>?,
+    @SerializedName("external_urls")
+    val externalUrls: ExternalUrls?,
+    val href: String?,
+    val id: String?,
+    val images: List<APIImage>?,
+    val name: String?,
+    @SerializedName("release_date")
+    val releaseDate: String?,
+    @SerializedName("release_date_precision")
+    val releaseDatePrecision: String?,
+    val restrictions: Restrictions?,
+    val type: String?,
+    val uri: String?,
+    val artists: List<Artist>?,
+    val tracks: Tracks?,
+    val copyrights: List<Copyright>?,
+    @SerializedName("external_ids")
+    val externalIds: ExternalIDs?,
+    val genres: List<String>?,
+    val label: String?,
+    val popularity: Int?
+)
+
+// MARK: - PlaylistItem Model
+data class PlaylistItem(
+    val collaborative: Boolean?,
+    val description: String?,
+    @SerializedName("external_urls")
+    val externalUrls: ExternalURLs?,
+    val followers: Followers?,
+    val href: String?,
+    val id: String?,
+    val images: List<APIImage>?,
+    val name: String?,
+    val owner: Owner?,
+    @SerializedName("public")
+    val publicAccess: Boolean?,
+    @SerializedName("snapshot_id")
+    val snapshotID: String?,
+    val tracks: Tracks?,
+    val type: String?,
+    val uri: String?
+)
+
+// MARK: - Show Model (Podcast)
+data class Show(
+    @SerializedName("available_markets")
+    val availableMarkets: List<String>?,
+    val copyrights: List<Copyright>?,
+    val description: String?,
+    @SerializedName("html_description")
+    val htmlDescription: String?,
+    val explicit: Boolean?,
+    @SerializedName("external_urls")
+    val externalUrls: ExternalUrls?,
+    val href: String?,
+    val id: String?,
+    val images: List<APIImage>?,
+    @SerializedName("is_externally_hosted")
+    val isExternallyHosted: Boolean?,
+    val languages: List<String>?,
+    @SerializedName("media_type")
+    val mediaType: String?,
+    val name: String?,
+    val publisher: String?,
+    val type: String?,
+    val uri: String?,
+    @SerializedName("total_episodes")
+    val totalEpisodes: Int?
+)
+
+// MARK: - Episode Model
+data class Episode(
+    @SerializedName("audio_preview_url")
+    val audioPreviewURL: String?,
+    val description: String?,
+    @SerializedName("html_description")
+    val htmlDescription: String?,
+    @SerializedName("duration_ms")
+    val durationMs: Int?,
+    val explicit: Boolean?,
+    @SerializedName("external_urls")
+    val externalURLs: ExternalURLs?,
+    val href: String?,
+    val id: String?,
+    val images: List<APIImage>?,
+    @SerializedName("is_externally_hosted")
+    val isExternallyHosted: Boolean?,
+    @SerializedName("is_playable")
+    val isPlayable: Boolean?,
+    val language: String?,
+    val languages: List<String>?,
+    val name: String?,
+    @SerializedName("release_date")
+    val releaseDate: String?,
+    @SerializedName("release_date_precision")
+    val releaseDatePrecision: String?,
+    @SerializedName("resume_point")
+    val resumePoint: ResumePoint?,
+    val type: String?,
+    val uri: String?,
+    val restrictions: Restrictions?,
+    val show: Show?
+)
+
+// ============================================================================
+// SUPPORTING MODELS
+// ============================================================================
+
+data class ExternalUrls(
+    val spotify: String?
+)
+
+data class ExternalURLs(
+    val spotify: String?
+)
+
+data class APIImage(
+    val url: String?,
+    val height: Int?,
+    val width: Int?
+)
+
+data class Restrictions(
+    val reason: String?
+)
+
+data class Artist(
+    val externalUrls: ExternalUrls?,
+    val href: String?,
+    val id: String?,
+    val name: String?,
+    val type: String?,
+    val uri: String?
+)
+
+data class Tracks(
+    val href: String?,
+    val limit: Int?,
+    val next: String?,
+    val offset: Int?,
+    val previous: String?,
+    val total: Int?,
+    val items: List<Track>?
+)
+
+data class Track(
+    val id: String?,
+    val name: String?,
+    val artists: List<Artist>?,
+    val album: Album?,
+    val durationMs: Int?,
+    val explicit: Boolean?,
+    val previewUrl: String?,
+    val uri: String?
+)
+
+data class Copyright(
+    val text: String?,
+    val type: String?
+)
+
+data class ExternalIDs(
+    val isrc: String?,
+    val ean: String?,
+    val upc: String?
+)
+
+data class Followers(
+    val href: String?,
+    val total: Int?
+)
+
+data class Owner(
+    val externalUrls: ExternalUrls?,
+    val followers: Followers?,
+    val href: String?,
+    val id: String?,
+    val type: String?,
+    val uri: String?,
+    val displayName: String?
+)
+
+data class ResumePoint(
+    @SerializedName("fully_played")
+    val fullyPlayed: Boolean?,
+    @SerializedName("resume_position_ms")
+    val resumePositionMS: Int?
+)
+