pubnub · jakub-grzesiowski · Jun 9, 2026 · Jun 3, 2026 · Jun 8, 2026 · Jun 8, 2026
@@ -1,8 +1,13 @@
 name: c-sharp
-version: "8.2.1"
+version: "8.3.0"
 schema: 1
 scm: github.com/pubnub/c-sharp
 changelog:
+  - date: 2026-06-08
+    version: v8.3.0
+    changes:
+      - type: feature
+        text: "Added a EnableHttp2 flag to the config which if set to true (the default value) will make all calls in the HttpClientService request Http/2 by default and fall back to Http/1.1 if not available on the origin."
   - date: 2026-05-29
     version: v8.2.1
     changes:
@@ -989,14 +994,14 @@ features:
     - QUERY-PARAM
 supported-platforms:
   -
-    version: Pubnub 'C#' 8.2.1
+    version: Pubnub 'C#' 8.3.0
     platforms:
       - Windows 10 and up
       - Windows Server 2008 and up
     frameworks:
       - .Net Framework 4.5+
   -
-    version: PubnubPCL 'C#' 8.2.1
+    version: PubnubPCL 'C#' 8.3.0
     platforms:
       - Xamarin.Android
       - Xamarin.iOS
@@ -1008,7 +1013,7 @@ supported-platforms:
     frameworks:
       - .Net 4.5+
   -
-    version: PubnubUWP 'C#' 8.2.1
+    version: PubnubUWP 'C#' 8.3.0
     platforms:
       - Windows Phone 10
       - Universal Windows Apps
@@ -1032,7 +1037,7 @@ sdks:
             distribution-type: source
             distribution-repository: GitHub
             package-name: Pubnub
-            location: https://github.com/pubnub/c-sharp/releases/tag/v8.2.1
+            location: https://github.com/pubnub/c-sharp/releases/tag/v8.3.0
             requires:
               -
                 name: ".Net"
@@ -1273,7 +1278,7 @@ sdks:
             distribution-type: source
             distribution-repository: GitHub
             package-name: PubNubPCL
-            location: https://github.com/pubnub/c-sharp/releases/tag/v8.2.1
+            location: https://github.com/pubnub/c-sharp/releases/tag/v8.3.0
             requires:
               -
                 name: ".Net"
@@ -1624,7 +1629,7 @@ sdks:
             distribution-type: source
             distribution-repository: GitHub
             package-name: PubnubUWP
-            location: https://github.com/pubnub/c-sharp/releases/tag/v8.2.1
+            location: https://github.com/pubnub/c-sharp/releases/tag/v8.3.0
             requires:
               -
                 name: "Universal Windows Platform Development"

@@ -1,3 +1,7 @@
+v8.3.0 - June 08 2026
+-----------------------------
+- Added: added a EnableHttp2 flag to the config which if set to true (the default value) will make all calls in the HttpClientService request Http/2 by default and fall back to Http/1.1 if not available on the origin.
+
 v8.2.1 - May 29 2026
 -----------------------------
 - Fixed: fixes issue of hereNow returning incorrect Occupancy when Occupancy count value is omitted from the response of single channel hereNow call.

@@ -240,6 +240,18 @@ public PNReconnectionPolicy ReconnectionPolicy {
 
         public int FileMessagePublishRetryLimit { get; set; }
 
+        /// <summary>
+        /// When enabled (default), each outbound request negotiates HTTP/2 using
+        /// <see cref="System.Net.Http.HttpRequestMessage.Version"/> / VersionPolicy, with
+        /// automatic fallback to HTTP/1.1. HTTP/2 only takes effect against an HTTP/2-capable
+        /// (customer-enabled) PubNub origin; otherwise requests transparently use HTTP/1.1.
+        /// The negotiated protocol is re-evaluated on new connections (natural reconnect or
+        /// Pubnub client recreation); the SDK does not pin or proactively probe for HTTP/2.
+        /// On target frameworks without VersionPolicy support (netstandard2.0/.NET Framework),
+        /// only the request version is set as a best-effort hint.
+        /// </summary>
+        public bool EnableHttp2 { get; set; } = true;
+
         [Obsolete("PNConfiguration(string uuid) is deprecated, please use PNConfiguration(UserId userId) instead.")]
         public PNConfiguration(string uuid)
         {
@@ -286,6 +298,7 @@ private void ConstructorInit(UserId currentUserId)
             userId = currentUserId;
             LogLevel = PubnubLogLevel.None;
             EnableEventEngine = true;
+            EnableHttp2 = true;
         }
 
         private void setDefaultRetryConfigurationFromPolicy(PNReconnectionPolicy policy)

@@ -11,8 +11,8 @@
 [assembly: AssemblyProduct("Pubnub C# SDK")]
 [assembly: AssemblyCopyright("Copyright ©  2021")]
 [assembly: AssemblyTrademark("")]
-[assembly: AssemblyVersion("8.2.1")]
-[assembly: AssemblyFileVersion("8.2.1")]
+[assembly: AssemblyVersion("8.3.0")]
+[assembly: AssemblyFileVersion("8.3.0")]
 // Setting ComVisible to false makes the types in this assembly not visible
 // to COM components.  If you need to access a type in this assembly from
 // COM, set the ComVisible attribute to true on that type.

@@ -1262,7 +1262,7 @@ public Pubnub(PNConfiguration config, IHttpClientService httpTransportService =
             //Defaulting to DotNet PNSDK source if no custom one is specified
             Version = (ipnsdkSource == default) ? new DotNetPNSDKSource().GetPNSDK() : ipnsdkSource.GetPNSDK();
             IHttpClientService httpClientService =
-                httpTransportService ?? new HttpClientService(proxy: config.Proxy);
+                httpTransportService ?? new HttpClientService(proxy: config.Proxy, enableHttp2: config.EnableHttp2);
             httpClientService.SetLogger(logger);
             transportMiddleware = middleware ?? new Middleware(httpClientService, config, this, tokenManager);
             logger?.Debug(GetConfigurationLogString(config));

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net60</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <LangVersion>latest</LangVersion>
     <SignAssembly>True</SignAssembly>
     <AssemblyOriginatorKeyFile>pubnub.snk</AssemblyOriginatorKeyFile>
@@ -14,16 +14,15 @@
 
   <PropertyGroup>
     <PackageId>Pubnub</PackageId>
-    <PackageVersion>8.2.1</PackageVersion>
+    <PackageVersion>8.3.0</PackageVersion>
     <Title>PubNub C# .NET - Web Data Push API</Title>
     <Authors>Pandu Masabathula</Authors>
     <Owners>PubNub</Owners>
     <PackageLicenseFile>LICENSE.txt</PackageLicenseFile>
     <PackageIconUrl>http://pubnub.s3.amazonaws.com/2011/powered-by-pubnub/pubnub-icon-600x600.png</PackageIconUrl>
     <PackageRequireLicenseAcceptance>true</PackageRequireLicenseAcceptance>
     <RepositoryUrl>https://github.com/pubnub/c-sharp/</RepositoryUrl>
-    <PackageReleaseNotes>Fixes issue of hereNow returning incorrect Occupancy when Occupancy count value is omitted from the response of single channel hereNow call.
-Fix for `HereNow` omitting the channel entry for an empty channel when UUIDs are included.</PackageReleaseNotes>
+    <PackageReleaseNotes>Added a EnableHttp2 flag to the config which if set to true (the default value) will make all calls in the HttpClientService request Http/2 by default and fall back to Http/1.1 if not available on the origin.</PackageReleaseNotes>
     <PackageTags>Web Data Push Real-time Notifications ESB Message Broadcasting Distributed Computing</PackageTags>
     <!--<Summary>PubNub is a Massively Scalable Web Push Service for Web and Mobile Games.  This is a cloud-based service for broadcasting messages to thousands of web and mobile clients simultaneously</Summary>-->
     <Description>PubNub is a Massively Scalable Web Push Service for Web and Mobile Games.  This is a cloud-based service for broadcasting messages to thousands of web and mobile clients simultaneously</Description>

@@ -11,10 +11,16 @@ namespace PubnubApi
     public class HttpClientService : IHttpClientService
     {
         private readonly HttpClient httpClient;
+        private readonly bool enableHttp2;
         private PubnubLogModule logger;
 
-        public HttpClientService(IWebProxy proxy)
+        public HttpClientService(IWebProxy proxy) : this(proxy, true)
         {
+        }
+
+        public HttpClientService(IWebProxy proxy, bool enableHttp2)
+        {
+            this.enableHttp2 = enableHttp2;
             httpClient = new HttpClient()
             {
                 Timeout = Timeout.InfiniteTimeSpan
@@ -28,6 +34,39 @@ public HttpClientService(IWebProxy proxy)
             httpClient.Timeout = Timeout.InfiniteTimeSpan;
         }
 
+        /// <summary>
+        /// Creates a transport backed by a caller-supplied <see cref="HttpMessageHandler"/>.
+        /// Intended for testing and advanced transport scenarios (e.g. observing outgoing
+        /// requests or stubbing responses). The supplied handler is fully responsible for
+        /// TLS/certificate validation and proxy behavior; the SDK does not weaken or override
+        /// them here. Do not pass a handler that disables certificate validation in production.
+        /// </summary>
+        /// <param name="handler">The message handler used to send requests.</param>
+        /// <param name="enableHttp2">Whether outbound requests should request HTTP/2 with HTTP/1.1 fallback.</param>
+        public HttpClientService(HttpMessageHandler handler, bool enableHttp2)
+        {
+            this.enableHttp2 = enableHttp2;
+            httpClient = new HttpClient(handler)
+            {
+                Timeout = Timeout.InfiniteTimeSpan
+            };
+        }
+
+        // HTTP/2 is requested by default; RequestVersionOrLower guarantees HTTP/1.1 fallback
+        // against non-HTTP/2 origins. Set per HttpRequestMessage because the SDK uses explicit
+        // request messages over a shared HttpClient.
+        private void ConfigureHttpVersion(HttpRequestMessage requestMessage)
+        {
+            if (!enableHttp2)
+            {
+                return;
+            }
+            requestMessage.Version = new Version(2, 0);
+#if NET6_0_OR_GREATER || NET60
+            requestMessage.VersionPolicy = HttpVersionPolicy.RequestVersionOrLower;
+#endif
+        }
+
         public void SetLogger(PubnubLogModule logger)
         {
             this.logger = logger;
@@ -41,6 +80,7 @@ public async Task<TransportResponse> GetRequest(TransportRequest transportReques
             {
                 HttpRequestMessage requestMessage =
                     new HttpRequestMessage(method: HttpMethod.Get, requestUri: transportRequest.RequestUrl);
+                ConfigureHttpVersion(requestMessage);
                 if (transportRequest.Headers.Keys.Count > 0)
                 {
                     foreach (var kvp in transportRequest.Headers)
@@ -68,8 +108,11 @@ public async Task<TransportResponse> GetRequest(TransportRequest transportReques
                     StatusCode = (int)httpResult.StatusCode,
                     Content = responseContent,
                     Headers = httpResult.Headers.ToDictionary(h => h.Key, h => h.Value),
-                    RequestUrl = httpResult.RequestMessage?.RequestUri?.AbsolutePath
+                    RequestUrl = httpResult.RequestMessage?.RequestUri?.AbsolutePath,
+                    NegotiatedProtocolVersion = httpResult.Version
                 };
+                logger?.Debug(
+                    $"PubNub request completed: operation={transportRequest.OperationType} protocol=HTTP/{httpResult.Version}");
                 logger?.Debug(
                     $"HttpClient Service: Received http response from server with status code {httpResult.StatusCode}, content-length: {transportResponse.Content.Length} bytes, for url \n{transportRequest.RequestUrl}");
             }
@@ -118,6 +161,7 @@ public async Task<TransportResponse> PostRequest(TransportRequest transportReque
                 HttpRequestMessage requestMessage =
                     new HttpRequestMessage(method: HttpMethod.Post, requestUri: transportRequest.RequestUrl)
                         { Content = postData };
+                ConfigureHttpVersion(requestMessage);
                 // Set Http Request header, When the header is not a payload content header.
                 if (transportRequest.Headers.Keys.Count > 0 && transportRequest.BodyContentBytes == null)
                 {
@@ -145,8 +189,11 @@ public async Task<TransportResponse> PostRequest(TransportRequest transportReque
                     StatusCode = (int)httpResult.StatusCode,
                     Content = responseContent,
                     Headers = httpResult.Headers.ToDictionary(h => h.Key, h => h.Value),
-                    RequestUrl = httpResult.RequestMessage?.RequestUri?.AbsolutePath
+                    RequestUrl = httpResult.RequestMessage?.RequestUri?.AbsolutePath,
+                    NegotiatedProtocolVersion = httpResult.Version
                 };
+                logger?.Debug(
+                    $"PubNub request completed: operation={transportRequest.OperationType} protocol=HTTP/{httpResult.Version}");
                 logger?.Debug(
                     $"Received http response from server with status code {httpResult.StatusCode}, content-length: {transportResponse.Content.Length} bytes, for url {transportRequest.RequestUrl}");
             }
@@ -197,6 +244,7 @@ public async Task<TransportResponse> PutRequest(TransportRequest transportReques
                 HttpRequestMessage requestMessage =
                     new HttpRequestMessage(method: HttpMethod.Put, requestUri: transportRequest.RequestUrl)
                         { Content = putData };
+                ConfigureHttpVersion(requestMessage);
                 if (transportRequest.Headers.Keys.Count > 0)
                 {
                     foreach (var kvp in transportRequest.Headers)
@@ -224,8 +272,11 @@ public async Task<TransportResponse> PutRequest(TransportRequest transportReques
                     StatusCode = (int)httpResult.StatusCode,
                     Content = responseContent,
                     Headers = httpResult.Headers.ToDictionary(h => h.Key, h => h.Value),
-                    RequestUrl = httpResult.RequestMessage?.RequestUri?.AbsolutePath
+                    RequestUrl = httpResult.RequestMessage?.RequestUri?.AbsolutePath,
+                    NegotiatedProtocolVersion = httpResult.Version
                 };
+                logger?.Debug(
+                    $"PubNub request completed: operation={transportRequest.OperationType} protocol=HTTP/{httpResult.Version}");
                 logger?.Debug(
                     $"Received http response from server with status code {httpResult.StatusCode}, content-length: {transportResponse.Content.Length} bytes, for url {transportRequest.RequestUrl}");
             }
@@ -260,6 +311,7 @@ public async Task<TransportResponse> DeleteRequest(TransportRequest transportReq
             {
                 HttpRequestMessage requestMessage =
                     new HttpRequestMessage(method: HttpMethod.Delete, requestUri: transportRequest.RequestUrl);
+                ConfigureHttpVersion(requestMessage);
                 if (transportRequest.Headers.Keys.Count > 0)
                 {
                     foreach (var kvp in transportRequest.Headers)
@@ -287,8 +339,11 @@ public async Task<TransportResponse> DeleteRequest(TransportRequest transportReq
                     StatusCode = (int)httpResult.StatusCode,
                     Content = responseContent,
                     Headers = httpResult.Headers.ToDictionary(h => h.Key, h => h.Value),
-                    RequestUrl = httpResult.RequestMessage?.RequestUri?.AbsolutePath
+                    RequestUrl = httpResult.RequestMessage?.RequestUri?.AbsolutePath,
+                    NegotiatedProtocolVersion = httpResult.Version
                 };
+                logger?.Debug(
+                    $"PubNub request completed: operation={transportRequest.OperationType} protocol=HTTP/{httpResult.Version}");
                 logger?.Debug(
                     $"Received http response from server with status code {httpResult.StatusCode}, content-length: {transportResponse.Content.Length} bytes, for url {transportRequest.RequestUrl}");
             }
@@ -340,6 +395,7 @@ public async Task<TransportResponse> PatchRequest(TransportRequest transportRequ
                 HttpRequestMessage requestMessage =
                     new HttpRequestMessage(new HttpMethod("PATCH"), requestUri: transportRequest.RequestUrl)
                         { Content = patchData };
+                ConfigureHttpVersion(requestMessage);
                 if (transportRequest.Headers.Keys.Count > 0)
                 {
                     foreach (var kvp in transportRequest.Headers)
@@ -367,8 +423,11 @@ public async Task<TransportResponse> PatchRequest(TransportRequest transportRequ
                     StatusCode = (int)httpResult.StatusCode,
                     Content = responseContent,
                     Headers = httpResult.Headers.ToDictionary(h => h.Key, h => h.Value),
-                    RequestUrl = httpResult.RequestMessage?.RequestUri?.AbsolutePath
+                    RequestUrl = httpResult.RequestMessage?.RequestUri?.AbsolutePath,
+                    NegotiatedProtocolVersion = httpResult.Version
                 };
+                logger?.Debug(
+                    $"PubNub request completed: operation={transportRequest.OperationType} protocol=HTTP/{httpResult.Version}");
                 logger?.Debug(
                     $"Received http response from server with status code {httpResult.StatusCode}, content-length: {transportResponse.Content.Length} bytes, for url {transportRequest.RequestUrl}");
             }

@@ -100,6 +100,7 @@ public TransportRequest PreapareTransportRequest(RequestParameter requestParamet
 			var transportRequest = new TransportRequest()
 			{
 				RequestType = requestParameter.RequestType,
+				OperationType = operationType,
 				RequestUrl = urlString,
 				BodyContentString = requestParameter.BodyContentString,
 				FormData = requestParameter.FormData,

@@ -7,6 +7,7 @@ namespace PubnubApi
 	public class TransportRequest
 	{
 		public string RequestType { get; set; }
+		public PNOperationType OperationType { get; set; }
 		public Dictionary<string, string> Headers { get; set; } = new Dictionary<string, string>();
 		public string RequestUrl { get; set; }
 		public byte[] FormData { get; set; } = default;

@@ -9,6 +9,12 @@ public class TransportResponse
 		public byte[] Content { get; set; }
 		public Dictionary<string, IEnumerable<string>> Headers { get; set; }
 		public string RequestUrl { get; set; }
+
+		/// <summary>
+		/// The negotiated HTTP protocol version of the response (e.g. 2.0 or 1.1),
+		/// taken from HttpResponseMessage.Version. Null when no response was received.
+		/// </summary>
+		public Version NegotiatedProtocolVersion { get; set; }
 		public Exception Error { get; set; }
 
 		public bool IsTimeOut {get; set;}

@@ -14,16 +14,15 @@
 
   <PropertyGroup>
     <PackageId>PubnubPCL</PackageId>
-    <PackageVersion>8.2.1</PackageVersion>
+    <PackageVersion>8.3.0</PackageVersion>
     <Title>PubNub C# .NET - Web Data Push API</Title>
     <Authors>Pandu Masabathula</Authors>
     <Owners>PubNub</Owners>
     <PackageLicenseFile>LICENSE.txt</PackageLicenseFile>
     <PackageIconUrl>http://pubnub.s3.amazonaws.com/2011/powered-by-pubnub/pubnub-icon-600x600.png</PackageIconUrl>
     <PackageRequireLicenseAcceptance>true</PackageRequireLicenseAcceptance>
     <RepositoryUrl>https://github.com/pubnub/c-sharp/</RepositoryUrl>
-    <PackageReleaseNotes>Fixes issue of hereNow returning incorrect Occupancy when Occupancy count value is omitted from the response of single channel hereNow call.
-Fix for `HereNow` omitting the channel entry for an empty channel when UUIDs are included.</PackageReleaseNotes>
+    <PackageReleaseNotes>Added a EnableHttp2 flag to the config which if set to true (the default value) will make all calls in the HttpClientService request Http/2 by default and fall back to Http/1.1 if not available on the origin.</PackageReleaseNotes>
     <PackageTags>Web Data Push Real-time Notifications ESB Message Broadcasting Distributed Computing</PackageTags>
     <!--<Summary>PubNub is a Massively Scalable Web Push Service for Web and Mobile Games.  This is a cloud-based service for broadcasting messages to thousands of web and mobile clients simultaneously</Summary>-->
     <Description>PubNub is a Massively Scalable Web Push Service for Web and Mobile Games.  This is a cloud-based service for broadcasting messages to thousands of web and mobile clients simultaneously</Description>