diff --git a/Sources/StreamCore/Utils/Atomic.swift b/Sources/StreamCore/Concurrency/Atomic.swift
similarity index 100%
rename from Sources/StreamCore/Utils/Atomic.swift
rename to Sources/StreamCore/Concurrency/Atomic.swift
diff --git a/Sources/StreamCore/Utils/StreamConcurrency.swift b/Sources/StreamCore/Concurrency/StreamConcurrency.swift
similarity index 100%
rename from Sources/StreamCore/Utils/StreamConcurrency.swift
rename to Sources/StreamCore/Concurrency/StreamConcurrency.swift
diff --git a/Sources/StreamCore/Utils/Data+Gzip.swift b/Sources/StreamCore/Utils/Data+Gzip.swift
index 7b834fa..007b19b 100644
--- a/Sources/StreamCore/Utils/Data+Gzip.swift
+++ b/Sources/StreamCore/Utils/Data+Gzip.swift
@@ -35,7 +35,7 @@ extension Data {
     ///
     /// - Returns: Gzip-compressed `Data` instance.
     /// - Throws: `GzipError`
-    func gzipped() throws -> Data {
+    public func gzipped() throws -> Data {
         guard !isEmpty else {
             return Data()
         }
diff --git a/Sources/StreamCore/Utils/HTTPUtils.swift b/Sources/StreamCore/Utils/HTTPUtils.swift
index cb3a3d1..0e988e3 100644
--- a/Sources/StreamCore/Utils/HTTPUtils.swift
+++ b/Sources/StreamCore/Utils/HTTPUtils.swift
@@ -5,7 +5,7 @@
 import Foundation
 
 extension URLRequest {
-    var queryItems: [URLQueryItem] {
+    public var queryItems: [URLQueryItem] {
         if let url,
            let urlComponents = URLComponents(url: url, resolvingAgainstBaseURL: false),
            let queryItems = urlComponents.queryItems {
@@ -16,7 +16,7 @@ extension URLRequest {
 }
 
 extension Array where Element == URLQueryItem {
-    var prettyPrinted: String {
+    public var prettyPrinted: String {
         var message = ""
         
         forEach { item in
diff --git a/Sources/StreamCore/Utils/RawJSON.swift b/Sources/StreamCore/Utils/RawJSON.swift
index edd8bfb..7f9a367 100644
--- a/Sources/StreamCore/Utils/RawJSON.swift
+++ b/Sources/StreamCore/Utils/RawJSON.swift
@@ -15,7 +15,7 @@ public indirect enum RawJSON: Codable, Hashable, Sendable {
     case array([RawJSON])
     case `nil`
     
-    static let double = number
+    public static let double = number
     
     public init(from decoder: Decoder) throws {
         let singleValueContainer = try decoder.singleValueContainer()
@@ -294,7 +294,7 @@ extension RawJSON {
     /// let price = customData["flight"]?["price"].numberValue
     /// let destination = customData["flight"]?["destination"].stringValue
     /// ```
-    subscript(key: String) -> RawJSON? {
+    public subscript(key: String) -> RawJSON? {
         get {
             guard case let .dictionary(dict) = self else {
                 return nil
@@ -320,7 +320,7 @@ extension RawJSON {
     /// let customData = message.customData
     /// let secondFlightPrice = customData["flights"]?[1]?["price"] ?? 0
     /// ```
-    subscript(index: Int) -> RawJSON? {
+    public subscript(index: Int) -> RawJSON? {
         get {
             guard case let .array(array) = self else {
                 return nil
diff --git a/Sources/StreamCore/Utils/StreamRuntimeCheck.swift b/Sources/StreamCore/Utils/StreamRuntimeCheck.swift
index 7ad1009..0e48e83 100644
--- a/Sources/StreamCore/Utils/StreamRuntimeCheck.swift
+++ b/Sources/StreamCore/Utils/StreamRuntimeCheck.swift
@@ -9,26 +9,4 @@ public enum StreamRuntimeCheck {
     ///
     /// When set to false, a message will be logged on console, but the assertion will not be thrown.
     public nonisolated(unsafe) static var assertionsEnabled = false
-
-    /// For *internal use* only
-    ///
-    ///  Established the maximum depth of relationships to fetch when performing a mapping
-    ///
-    ///  Eg.
-    ///  Relationship:    Message --->  QuotedMessage --->    QuotedMessage   ---X---     NIL
-    ///  Relationship:    Channel  --->      Message         --->     QuotedMessage  ---X---     NIL
-    ///  Depth:                     0                         1                                     2                               3
-    nonisolated(unsafe) static var _backgroundMappingRelationshipsMaxDepth = 2
-
-    /// For *internal use* only
-    ///
-    ///  Returns true if the maximum depth of relationships to fetch when performing a mapping is not yet met
-    static func _canFetchRelationship(currentDepth: Int) -> Bool {
-        currentDepth <= _backgroundMappingRelationshipsMaxDepth
-    }
-    
-    /// For *internal use* only
-    ///
-    /// Core Data prefetches data used for creating immutable model objects (faulting is disabled).
-    public nonisolated(unsafe) static var _isDatabasePrefetchingEnabled = false
 }
diff --git a/Sources/StreamCore/Utils/StringExtensions.swift b/Sources/StreamCore/Utils/StringExtensions.swift
index fd71356..37d4d0c 100644
--- a/Sources/StreamCore/Utils/StringExtensions.swift
+++ b/Sources/StreamCore/Utils/StringExtensions.swift
@@ -53,7 +53,7 @@ extension String {
 }
 
 extension StringProtocol {
-    func ranges<S: StringProtocol>(of string: S, options: String.CompareOptions = []) -> [Range<String.Index>] {
+    public func ranges<S: StringProtocol>(of string: S, options: String.CompareOptions = []) -> [Range<String.Index>] {
         var result: [Range<Index>] = []
         var startIndex = startIndex
         while startIndex < endIndex, let range = self[startIndex...].range(of: string, options: options) {
diff --git a/Sources/StreamCore/Utils/Timers.swift b/Sources/StreamCore/Utils/Timers.swift
index b604ca0..2526b63 100644
--- a/Sources/StreamCore/Utils/Timers.swift
+++ b/Sources/StreamCore/Utils/Timers.swift
@@ -55,6 +55,7 @@ public protocol TimerControl {
 }
 
 extension DispatchWorkItem: TimerControl {}
+extension DispatchWorkItem: @retroactive @unchecked Sendable {}
 
 /// Default real-world implementations of timers.
 public struct DefaultTimer: StreamTimer {
@@ -116,7 +117,11 @@ private class RepeatingTimer: RepeatingTimerControl, @unchecked Sendable {
 
     private let queue = DispatchQueue(label: "io.getstream.repeating-timer")
     private var state: State = .suspended
+    #if compiler(>=6.1)
     private let timer: DispatchSourceTimer
+    #else
+    private nonisolated(unsafe) let timer: DispatchSourceTimer
+    #endif
 
     init(timeInterval: TimeInterval, queue: DispatchQueue, onFire: @escaping () -> Void) {
         timer = DispatchSource.makeTimerSource(queue: queue)