The best way to install Raygun4Net is to use the NuGet package manager. With the NuGet Visual Studio extension installed, right-click on your project and select "Manage NuGet Packages..." Make sure "Online" is highlighted in the left hand pane, then use the top right search box to find Mindscape.Raygun4Net and install it.

Alternatively, visit for instructions on installation using the package manager console.

In the App.xaml.cs constructor (or any main entry point to your application), call the static RaygunClient.Attach method with your app API key. Your app API key is displayed when you create a new application in your Raygun account, or can be viewed in the application settings.

using Mindscape.Raygun4Net;
public App()

Raygun4Net will now automatically detect and send all unhandled exceptions to your Raygun account where you can view all of your error monitoring and crash report data.

Deploy Raygun into your production environment for best results, or raise a test exception. Once we detect your first error event, the Raygun app will automatically update.

The above instructions will setup Raygun4Net to automatically detect and send all unhandled exceptions. Sometimes you may want to send exceptions manually, such as handled exceptions from within a try/catch block.

RaygunClient provides a Send method for manually sending exceptions to Raygun. The Send method has options for sending additional data which are explained in the various feature sections below.

Here's an example of manually sending exceptions from a try/catch block:

  // Do something here that might go wrong
catch (Exception e)

Sometimes you may have code that detects that something has gone wrong, but doesn't actually throw an exception. If you want to log this to Raygun, it is tempting to just create a new exception instance and pass it through one of the RaygunClient send methods. Note however that a .NET exception needs to be thrown in order for its stack trace to be populated. So whenever you want to send a new exception instance to Raygun, make sure you are throwing the exception, then catch and send it from within a try/catch block as in the code example above. This will ensure that you log the stack trace which is useful for you to debug, and is used by Raygun to group exceptions.

On a RaygunClient instance, attach an event handler to the SendingMessage event. This event handler will be called just before the RaygunClient sends an exception report - either automatically or manually. The event arguments provide the RaygunMessage object that is about to be sent. There are two different uses for this event handler:

  • Modify the message. You can make any changes you want to the RaygunMessage object such as removing, adding or changing values. Any changes that you make will affect the exception report that gets sent to Raygun.
  • Cancel the message. Sometimes you may get exceptions from parts of the application that you have no control over (such as 3rd party libraries) or due to issues that cannot be solved. In this event handler, you can look through the properties of the RaygunMessage to determine if the exception is one that you don't care about. If so, you can then set e.Cancel = true to prevent Raygun4Net from sending it.

Here is an example of cancelling a message. This code extends upon the setup instructions detailed above.

public App()
  // Attach the event handler:
  RaygunClient.Current.SendingMessage += RaygunClient_SendingMessage;

private void RaygunClient_SendingMessage(object sender, RaygunSendingMessageEventArgs e)
  // This is an example of cancelling a message:
  if ("NotImplementedException".Equals(e.Message.Details.Error.ClassName))
    e.Cancel = true;

Note that if an exception occurs within your SendingMessage event handler, Raygun4Net will detect this and send the new exception as well as the original exception that was being processed. When processing the new exception, the event handler will not be called again in order to avoid an infinite loop.

When exception reports are sent to Raygun, they get grouped using our classification logic. We improve this logic every now and then, but sometimes you may come across scenarios where exceptions reports are grouped together or put into separate groups where you were not expecting. This can be from cases we are not yet handling, scenarios that are specific to your application, or unique grouping preferences you have. Raygun4Net lets you provide your own custom grouping logic before exceptions are sent to Raygun.

To use the custom grouping key feature, start by getting the RaygunClient instance used to send your exception reports and attach an event handler to the CustomGroupingKey event. This event gets fired before the SendingMessage event described in the section above. The event arguments provide both the original Exception object and the RaygunMessage object that is about to be sent. In the event handler, you can use whatever logic you want to build a grouping key (string) for the given exception. When the key is ready, set it to the CustomGroupingKey property of the event arguments. Exceptions that end up with the same key will be grouped together. Grouping keys have a limit of 100 characters.

Unless you have extreme grouping logic that needs to be applied to all exceptions, we recommend that you only apply custom grouping logic to scenarios that we are not handling for you. You can include checks in your event handler for certain types of exceptions for example, and only create a custom grouping key for them. Exceptions that you don't provide a custom grouping key for will be grouped in Raygun using the grouping classifiers we provide.

Here is an example of providing a custom grouping key. This code extends upon the setup instructions detailed above.

public App()
  // Attach the event handler:
  RaygunClient.Current.CustomGroupingKey += RaygunClient_CustomGroupingKey;

private void RaygunClient_CustomGroupingKey(object sender, RaygunCustomGroupingKeyEventArgs e)
  // This example simply performs pure message based grouping on basic Exception instances:
  if (e.Message.Details.Error.ClassName.Equals("Exception"))
    string key = e.Exception.Message;
    e.CustomGroupingKey = key;

Note that if an exception occurs within your CustomGroupingKey event handler, Raygun4Net will detect this and send the new exception as well as the original exception that was being processed. When processing the new exception, the event handler will not be called again in order to avoid an infinite loop.

Providing user information will allow your Raygun dashboard to display the number of unique users that each error or crash has affected. This is a huge help with prioritising issues to solve that have the largest impact. You can provide whatever user information that will help you solve issues, but make sure to abide by any privacy policies that your company follows. At the very least, providing a unique guid will allow you to see the number of users that are affected by each error. If available, you could provide an ID that is meaningful to you such as a database ID. This could help you to look up information at your end that aids in solving issues. If you are able to provide a name and contact details, you'd be able to contact customers to let them know that issues they've encountered are being worked on, or have been solved.

There are a couple of ways to provide user information, the simplest of which is to set the User property of the RaygunClient instance to an identifier of your choosing:

RaygunClient.Current.User = "";

If a single identifier string isn't enough, you can set the UserInfo property instead to provide more information:

RaygunClient.Current.UserInfo = new RaygunIdentifierMessage("")
  IsAnonymous = false,
  FullName = "Robbie Robot",
  FirstName = "Robbie"

Here are all the available RaygunIdentifierMessage properties:

  • Identifier (passed into the constructor) is the unique identifier from your system for this user.
  • IsAnonymous is a flag indicating whether the user is logged in (or identifiable) or if they are anonymous. An anonymous user can still have a unique identifier.
  • Email The user's email address. If you use email addresses to identify your users, feel free to set the identifier to their email and leave this blank. We will use the identifier as the email address if it looks like one, and if no email address is specified in this field.
  • FullName The user's full name.
  • FirstName The user's first (or preferred) name.
  • UUID A device identifier. Could be used to identify users across devices, or machines that are breaking for many users.

The string properties on a User have a maximum length of 255 characters. Users who have fields that exceed this amount will not be processed.

Options on the Send method allows you to include a list of tags with each manually sent exception:

RaygunClient.Current.Send(exception, new List<string>() { "tag1", "tag2" });

Exceptions can be searched in your Raygun dashboard by tags that you've included.

You can include key-value custom data using an option on the Send method. Values can be primitive types or rich object structures. All properties of objects and their children will be sent to Raygun. Cyclic object references will be detected and handled as appropriate, and any property getter that produces an exception will cause that property value to be displayed as the exception message.

RaygunClient.Current.Send(exception, new Dictionary<string, object>() { { "key", "value" } });

By default, Raygun4Net will attempt to send the package version of your project with each report. If this is unavailable, or if you need to provide your own custom version value, you can do so by setting the ApplicationVersion property of the RaygunClient.

RaygunClient.Current.ApplicationVersion = "";

If you have common outer exceptions that wrap a valuable inner exception which you'd prefer to group by, you can specify these by using the following multi-parameter method:


The above example will cause MyWrapperException instances to be stripped away and never sent to Raygun. Instead, only the inner exception of any stripped exceptions will be sent. By default TargetInvocationException will always be stripped - see below to override this behavior.

AggregateException is a special case as they can hold multiple inner exceptions. By stripping AggregateException instances using the method described above, all inner exceptions will be sent to Raygun as separate exception reports. That way, each inner exception can be put into the appropriate individual groups and managed separately.

If you want to prevent Raygun4Net from stripping the default wrapper exception (TargetInvocationException) then you can call the multi-parameter RemoveWrapperExceptions method as shown below. This can also be useful if you've used the above instructions to cause Raygun4Net to strip a wrapper exception type that you later don't want to strip within a single execution of the app.


All versions of Raygun4Net are signed with a strong name.

The provider is open source and available at the Raygun4Net repository.