v4.0.0-preview1

• [Core] Improved memory management when working with large payloads.
• [Core] Added support for .NET 6.0.
• [Core] nuget packages are now created by MSBuild including more information (i.e. commit hash).
• [Client] The OS will now choose the best TLS version to use. It is no longer fixed to 1.3 etc. (thanks to @patagonaa, #1271).
• [Client] Exposed user properties and reason string in subscribe result.
• [Client] Exposed user properties and reason string in unsubscribe result.
• [Server] Added support for returning individual subscription errors (#80 thanks to @JimCH)
• [Server] Improved topic filter comparisons (support for $).
• [Server] Added more MQTTv5 response information to all interceptors (BREAKING CHANGE!).
• [Server] Improved session management for MQTT v5 (#1294, thanks to @logicaloud).
• [Server] All interceptors and events are migrated from interfaces to simple events. All existing APIs are availble but must be migrated to corresponding events (BREAKING CHANGE!).
• [Server] Removed all interceptor and event interfaces including the delegate implementations etc. (BREAKING CHANGE!).
• [Server] Renamed a lot of classes and adjsuted namespaces (BREAKING CHANGE!).
• [Server] Introduced a new queueing approach for internal message process (packet bus).

v3.1.1

• [Core] Removed IDisposable from MqttClientConnection.cs (#1284).
• [Core] Improved message of timeout exception (#1302, thanks to @patagonaa).
• [RpcClient] Filling response topic when using MQTTv5. (#1295, thanks to @MD-V).
• [Server] Fixed 'SessionIsPresent' handling for MQTTv5 (#1300, thanks to @logicaloud).
• [Server] Improved session management for MQTTv5 (#1294, thanks to @logicaloud).

v3.1.0

• [Core] Added all builders to the MQTT factory.
• [Core] Removed global logger and refactored logging (BREAKING CHANGE!).
• [Client] Renamed MqttClientAuthenticateResult to MqttClientConnectResult (BREAKING CHANGE!).
• [ManagedClient] Extended ReconnectAsync (thanks to @nvsnkv, #1202).
• [ManagedClient] Improved Amazon AWS support (thanks to @scottbrogden-iheartmedia, #1209).
• [ManagedClient] Fixed bug that allowed invalid subscriptions (Thanks to @marcelwinh).
• [Server] Added support for RetainHandling (MQTTv5, BREAKING CHANGE!).
• [Server] Added support for NoLocal (MQTTv5, BREAKING CHANGE!).
• [Server] Added support for SubscriptionIdentifier (MQTTv5, BREAKING CHANGE!).
• [Server] Server now reports supported features properly after successful connection (MQTTv5, BREAKING CHANGE!).
• [Server] Fixed a memory/performance leak when using QoS Level 1.
• [Server] Exposed connection timestamp in client status.
• [Server] Refactored connection management code.
• [Server] Exposed more details in MqttServerClientConnectedEventArgs.
• [Server] Processing all pending messages before stopping (thanks to @AblEdge, #1234).
• [Server] Added support for a custom exception handler in MqttServerMultiThreadedApplicationMessageInterceptorDelegate.
• [Server] Removed logger from MqttServerMultiThreadedApplicationMessageInterceptorDelegate (BREAKING CHANGE!).
• [Server] Fixed a memory leak when deleting sessions.
• [Server] Fixed timestamp check in server keep-alive monitor (thanks to @logicaloud, #1277).
• [MQTTnet.Server] Moved server project to a dedicated GitHub repository.

This version was released as 3.0.17 before which is wrong!

v3.0.16

• [Core] Fixed DISCONNECT packet reading for protocol version 3.1.0.DisconnectPacket
• [Client] Added support for deferred message approval (#1075, thanks to @tkurucsai).
• [Client] Exposed missing APIs for .NET 5.0 build (thanks to @yyjdelete).
• [Client] Improved disconnect handling (#1134, thanks to @yyjdelete).
• [Client] Fix TLS parameter options builder (#1104).
• [Server] Add new overload for options builder.
• [Server] Exposed endpoint in MqttServerClientDisconnectedEventArgs.
• [Server] Remove client disconnected handler from wrong implementation location (BREAKING CHANGE).

v3.0.15

• [Core] Fixed some issues in nuget packages.
• [Client] Changed exception types so that proper exceptions are thrown when connecting (#1082).
• [Client] Exposed Dup flag in application messages.
• [Client] Improved keep alive message sending.
• [RpcClient] Fixed an issue when using a custom application message reveived handler (#1093).
• [RpcClient] Fixed a race condition when using timeout and cancellation token at the same time (BREAKING CHANGE!).
• [Server] Improved keep alive message sending.

v3.0.14

• [Core] Added .NET 5.0 TFMs (thanks to @StefanOssendorf, @JanEggers).
• [Core] Added support for TLS 1.3 (requires .NET Core 3.1+) (thanks to @Dvergatal).
• [Core] Added support for MaximumQoS transmit when using MQTTv5 (thanks to @nayato).
• [Core] Aligned the format of some log messages.
• [Client] Fixed an issue with connection state detection (thanks to @tobiasfrick).
• [Client] Fixed an issue when receiving partial QoS 2 packets after a reconnect.
• [Client] Added new API for raw packet inspection.
• [ManagedClient] Removed AutoReconnect since this does no longer work (BREAKING CHANGE!).
• [RpcClient] Moved the RPC topic validation to the topic generation strategy.
• [RcpClient] Added interface for MqttRpcClient.
• [Server] Reduced async tasks count by moving dedicated keep alive tasks per connection to shared one.
• [Server] Session takeover and keep alive timeout are now properly set in DISCONNECT packet.
• [Server] Fixed bug in PubRel packet generation (MQTTv5 only).
• [Server] Improved message processing performance (+ ~5%).
• [Server] Fix wrong usage of client session items for undelivered messages.
• [Server] Allow to respond with a reason code in PUBACK/PUBREC (thanks to @muneebmajeed).
• [Server] Fixed topic filter comparer on edge cases, e.g. "foo/" matching "foo/#" (thanks to @dagophil).
• [Core] Added code documentation.

v3.0.13

• [Client] Fixed wrong value for "ClientWasConnected" in "MqttClientDisconnectedEventArgs" #976 (thanks to @dbeinder).
• [Client] Added direct support for Amazon AWS connections (requires .NET Core 3.1) (thanks to @henning-krause).
• [Client] handle disconnect package and propagate disconnect reason code (thanks to @JanEggers)
• [ManagedClient] Exposed the internal MQTT client.
• [Server] Added client message queue interceptor for QoS level (thanks to @msallin).
• [Server] improved behavior when multiple connections fight over a session (thanks to @JanEggers)
• [Server] Exposed ClientDisconnectedInterceptor (thanks to @SeppPenner).

v3.0.12

• [LowLevelClient] Fixed a null reference exception when connecting to a not existing server (thanks to @SGStino).
• [RcpClient] Adjusted some namespaces (BREAKING CHANGE!).
• [AspNetCore] Adjusted some namespaces (BREAKING CHANGE!).
• [Server] Adjusted some namespaces (BREAKING CHANGE!).
• [Server] Added state checks (throw if not started etc.) for most server APIs.
• [Server] Exposed real X509Certificate2 (instead byte array) to TLS options (thanks to @borigas).
• [Server] Fixed memory leak with TCP sockets (MqttServer is now Disposable!) (BREAKING CHANGE!).
• [Core] Fixed a null reference exception in the MqttTcpChannel with WriteAsync and ReadAsync.
• [Core] Added server interceptor for undelivered messages (thanks to @cshark-inator).
• [nuget] Added support for SourceLink (thanks to @JTOne123).

v3.0.11

• [Client] Fixed issue in keep alive handling.
• [MQTTnet.Server] Added support for delivering static files (HTML, JavaScript etc.).
• [MQTTnet.Server] Fixed web socket protocol errors (when using paho JS etc.).

v3.0.10

• [Core] Improved logger performance (BREAKING CHANGE!).
• [Core] Renamed some topic filter relevant classes (BREAKING CHANGE!).
• [Core] Improved task management for UWP connections (thanks to @xgstation).
• [Core] Fixed broken logger which decreases overall performance.
• [Core] Fixed issue in closed socket detection (fixes high CPU load issue).
• [Client] Added method to trigger PING/PONG manually (connection check etc.).
• [Client] Added support for certificate validation callback when using Web Sockets (requires netstandard2.1+).
• [Client] Fixed a memory leak when web socket based connections trying to reconnect with an offline server.
• [Client] Fixed a memory leak when TCP based connections trying to reconnect with an offline server.
• [Client] Fixed an issue when connecting to an invalid host (format).
• [Client] Added support for user properties in CONNECT packet.
• [Client] Removed KeepAliveSendInterval and improved keep alive handling (BREAKING CHANGE!).
• [ManagedClient] Added method to trigger PING/PONG manually (connection check etc.).
• [MQTTnet.AspNetCore] improved compatibility with AspNetCore 3.1.
• [MQTTnet.AspNetCore] Fixed several packaging issues with the Nuget package.
• [MQTTnet.Server] Fixed wrong version output.