MQTTnet

MQTTnet is a high performance .NET library for MQTT based communication. It provides a MQTT client and a MQTT server (broker) and supports the MQTT protocol up to version 5. It is compatible with mostly any supported .NET Framework version and CPU architecture.

Features

General

Async support
TLS support for client and server (but not UWP servers)
Extensible communication channels (e.g. In-Memory, TCP, TCP+TLS, WS)
Lightweight (only the low level implementation of MQTT, no overhead)
Performance optimized (processing ~150.000 messages / second)*
Uniform API across all supported versions of the MQTT protocol
Access to internal trace messages
Unit tested (~636 tests)
No external dependencies

* Tested on local machine (Intel i7 8700K) with MQTTnet client and server running in the same process using the TCP channel. The app for verification is part of this repository and stored in /Tests/MQTTnet.TestApp.NetCore.

Client

Communication via TCP (+TLS) or WS (WebSocket) supported
Included core LowLevelMqttClient with low level functionality
Also included ManagedMqttClient which maintains the connection and subscriptions automatically. Also application messages are queued and re-scheduled for higher QoS levels automatically.
Rx support (via another project)
Compatible with Microsoft Azure IoT Hub

Server (broker)

List of connected clients available
Supports connected clients with different protocol versions at the same time
Able to publish its own messages (no loopback client required)
Able to receive every message (no loopback client required)
Extensible client credential validation
Retained messages are supported including persisting via interface methods (own implementation required)
WebSockets supported (via ASP.NET Core 2.0, separate nuget)
A custom message interceptor can be added which allows transforming or extending every received application message
Validate subscriptions and deny subscribing of certain topics depending on requesting clients

Getting Started

MQTTnet is delivered via NuGet package manager. You can find the packages here: https://www.nuget.org/packages/MQTTnet/

Use these command in the Package Manager console to install MQTTnet manually:

Install-Package MQTTnet

Samples for using MQTTnet are part of this repository. For starters these samples are recommended:

Code of Conduct

This project has adopted the code of conduct defined by the Contributor Covenant to clarify expected behavior in our community. For more information see the .NET Foundation Code of Conduct.