NMS Documentation

API Overview

The NMS API (.Net Message Service API) provides a standard .NET interface to Messaging Systems. There are multiple implementations for different providers (including MSMQ). The NMS API allows you to build .NET applications in C#, VB, or any other .NET language, using a single API to connect to multiple different providers using a JMS style API.

NMS API currently supports all of the features of JMS in a simple pure C# API and implementation apart from XA. Current features include:

  • creating & disposing of connections, sessions, producers, consumers
  • sending of messages to topics, queues with durable or non durable along with temporary destination support
  • synchronous consuming (blocking receive, receive with no wait or receive with a timeout)
  • asynchronous consuming (adding a MessageListener to be dispatched in the thread pool)
  • message header support along with custom properties
  • Text, Bytes, Stream and Map message support
  • support for transactions (sending and acknowledging multiple messages in an atomic transaction)
  • redelivery of messages in rollbacks up to some configured maximum redelivery count
  • Optional Queue browser interface for providers that can support it.
  • Optional .NET Distributed Transaction Support for providers that can support that.

A provider implementation based on a pure C# implementation of OpenWire is provided for working with the Apache ActiveMQ broker. There are other provider implementations for working with Stomp, TIBCO EMS, Microsoft Message Queue (MSMQ), AMQP, and Windows Communication Foundation (WCF).

If you are curious you can browse the source code and tests for the entire project or download an NMS Provider.


An NMS Provider is a .NET Assembly that provides an implementation of the NMS API that provides connectivity with a particular Messaging Service or an implementation of a standard Messaging Protocol. Currently, the following providers are available:

  • AMQP provides support for AMQP 1.0 protocol. Compatible with ActiveMQ 5.x, ActiveMQ Artemis and any other AMQP 1.0 compliant broker.
  • ActiveMQ (OpenWire) client which communicates with ActiveMQ 5.x using its own native wire protocol and provides many advanced features beyond the standard NMS API.
  • STOMP which connects to any STOMP Broker. Also, when coupled with StompConnect, NMS can be used to communicate with pretty much any existing MOM provider! (Or at least those that support JMS which most MOM providers do).
  • MSMQ is an implementation of NMS using Microsoft’s MSMQ API.
  • EMS provider for talking to TIBCO’s EMS message broker. To use this, you will need to following TIBCO’s licensing requirements to acquire the TIBCO client assembly DLL. NMS does not ship with the TIBCO client assembly.
  • WCF provides support of Windows Communications Framework.

Building the code

While there are binary distributions available for all the NMS Providers you sometimes might want to build the code from trunk in order to test out the latest changes or fixes. On Windows you can use Visual Studio to build the code. On Linux or OS X you can use Mono.

The build uses NAnt which both work on .Net and Mono. You will need to have NAnt 0.91-Alpha2 or later.

For more help see the Building NMS guide.

Alternatives to NMS

There are currently a few alternatives to using NMS and working with ActiveMQ in .NET applications however the NMS ActiveMQ Provider is very feature rich and we recommend it as your starting point for .NET ActiveMQ inter-op.


This is where you will find examples of how to use the NMS API. These examples demonstrate using the NMS API generically and are limited to features exposed directly through the API model. For examples covering more advanced features of a specific NMS Provider, refer to the documentation for that NMS Provider.

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