diff --git a/Sources/DZNetworking/Core/DZOAuthSession.swift b/Sources/DZNetworking/Core/DZOAuthSession.swift
index 4f18f9c..6307ccf 100644
--- a/Sources/DZNetworking/Core/DZOAuthSession.swift
+++ b/Sources/DZNetworking/Core/DZOAuthSession.swift
@@ -7,7 +7,7 @@
 
 import Foundation
 
-enum OAuthError: LocalizedError {
+enum OAuthError: LocalizedError, Sendable {
   /// an auth session is already in progress
   case activeAuthState
   /// an invalid or no state token was received in the oauth verification callback
diff --git a/Sources/DZNetworking/Core/DZURLSession+Codable.swift b/Sources/DZNetworking/Core/DZURLSession+Codable.swift
index 9029999..1771d08 100644
--- a/Sources/DZNetworking/Core/DZURLSession+Codable.swift
+++ b/Sources/DZNetworking/Core/DZURLSession+Codable.swift
@@ -28,6 +28,10 @@ extension DZURLSession {
       throw PublicError.expectedData
     }
     
+    if data.isEmpty {
+      return (nil, response)
+    }
+    
     let decoder = decoder ?? DZURLSession.decoder
     let object = try decoder.decode(T.self, from: data)
     return (object, response)
@@ -48,6 +52,10 @@ extension DZURLSession {
       throw PublicError.expectedData
     }
     
+    if data.isEmpty {
+      return (nil, response)
+    }
+    
     let decoder = decoder ?? DZURLSession.decoder
     let object = try decoder.decode(T.self, from: data)
     return (object, response)
@@ -68,6 +76,10 @@ extension DZURLSession {
       throw PublicError.expectedData
     }
     
+    if data.isEmpty {
+      return (nil, response)
+    }
+    
     let decoder = decoder ?? DZURLSession.decoder
     let object = try decoder.decode(T.self, from: data)
     return (object, response)
diff --git a/Sources/DZNetworking/HTTPURLRQ/HTTPURLRQ.swift b/Sources/DZNetworking/HTTPURLRQ/HTTPURLRQ.swift
index d6ba81f..f12879b 100644
--- a/Sources/DZNetworking/HTTPURLRQ/HTTPURLRQ.swift
+++ b/Sources/DZNetworking/HTTPURLRQ/HTTPURLRQ.swift
@@ -19,7 +19,7 @@ import AppKit
 #endif
 
 /// This is Swift port OMGHTTPURLRQ
-struct HTTPURLRQ {
+struct HTTPURLRQ: Sendable {
   static let userAgent: String = {
     var ua = ""
     let info = Bundle.main.infoDictionary
@@ -28,13 +28,39 @@ struct HTTPURLRQ {
     
     #if canImport(UIKit)
     #if os(watchOS)
-    let scale = 2.0
-    let device = WKInterfaceDevice.current().model
-    let systemVersion = WKInterfaceDevice.current().systemVersion
+    let scale: CGFloat = 2.0
+    var device: String
+    var systemVersion: String
+    
+    if Thread.isMainThread {
+      device = WKInterfaceDevice.current().model
+      systemVersion = WKInterfaceDevice.current().systemVersion
+    }
+    else {
+      DispatchQueue.main.sync {
+        device = WKInterfaceDevice.current().model
+        systemVersion = WKInterfaceDevice.current().systemVersion
+      }
+    }
     #else
-    let scale = UIScreen.main.scale
-    let device = UIDevice.current.model
-    let systemVersion = UIDevice.current.systemVersion
+    var scale: CGFloat = 2.0
+    var device: String = ""
+    var systemVersion: String = ""
+    
+    if Thread.isMainThread {
+      MainActor.assumeIsolated {
+        scale = UIScreen.main.scale
+        device = UIDevice.current.model
+        systemVersion = UIDevice.current.systemVersion
+      }
+    }
+    else {
+      DispatchQueue.main.sync {
+        scale = UIScreen.main.scale
+        device = UIDevice.current.model
+        systemVersion = UIDevice.current.systemVersion
+      }
+    }
     #endif
     
     #if os(tvOS)
diff --git a/Sources/DZNetworking/Utilities/DZS3CredentialsManager.swift b/Sources/DZNetworking/Utilities/DZS3CredentialsManager.swift
index 8a84892..ec584d4 100644
--- a/Sources/DZNetworking/Utilities/DZS3CredentialsManager.swift
+++ b/Sources/DZNetworking/Utilities/DZS3CredentialsManager.swift
@@ -8,24 +8,24 @@
 import Foundation
 import CommonCrypto
 
-public enum DZS3Error: LocalizedError {
+public enum DZS3Error: LocalizedError, Sendable {
   case incompleteParamters
 }
 
 /// The Access-Control-List used for the uploaded object. Can be `public` or `private`, defaults to `public`.
-public enum DZACL: String {
+public enum DZACL: String, Sendable {
   case `private`
   case `public`
 }
 
 /// The S3 at-rest encryption used for the uploaded object. `none` by default.
-public enum DZS3Encryption: String {
+public enum DZS3Encryption: String, Sendable {
   case `none`
   case AES256
 }
 
 /// Credentials manager for S3 operations
-public struct DZS3CredentialsManager {
+public struct DZS3CredentialsManager: Sendable {
   /// the `AWSAccessKey`
   public let key: String
   /// the `AWSSecretKey`
@@ -174,9 +174,9 @@ public struct DZS3CredentialsManager {
   }
 }
 
-private extension String {
+extension String {
   
-  func sha256() -> String {
+  public func sha256() -> String {
     guard let data = self.data(using: .utf8) else { return "" }
     var hash = [UInt8](repeating: 0,  count: Int(CC_SHA256_DIGEST_LENGTH))
     data.withUnsafeBytes {
@@ -204,8 +204,8 @@ private extension String {
   }
 }
 
-private extension Data {
-  func toHexString() -> String {
+extension Data {
+  public func toHexString() -> String {
     let hexString = self.map{ String(format:"%02x", $0) }.joined()
     return hexString
   }