# ASP.NET | Sentry for ASP.NET

Sentry provides an integration with ASP.NET through the [Sentry.AspNet NuGet package](https://www.nuget.org/packages/Sentry.AspNet).

## [Features](https://docs.sentry.io/.md#features)

In addition to capturing errors, you can monitor interactions between multiple services or applications by [enabling tracing](https://docs.sentry.io/concepts/key-terms/tracing.md).

Select which Sentry features you'd like to install in addition to Error Monitoring to get the corresponding installation and configuration instructions below.

## [Install](https://docs.sentry.io/.md#install)

Error Monitoring\[ ]Tracing

Add the Sentry dependency:

```powershell
Install-Package Sentry.AspNet -Version 5.11.2
```

You can combine this integration with a logging library like `log4net`, `NLog` or `Serilog` to include both request data as well as your logs as breadcrumbs. The logging integrations also capture events when an error is logged.

## [Configure](https://docs.sentry.io/.md#configure)

You configure the SDK in the `Global.asax.cs`:

```csharp
using System;
using System.Web;
using Sentry.AspNet;
using Sentry.EntityFramework; // If you also installed Sentry.EntityFramework
using Sentry.Extensibility;

public class MvcApplication : HttpApplication
{
    private IDisposable _sentry;

    protected void Application_Start()
    {
        // Initialize Sentry to capture AppDomain unhandled exceptions and more.
        _sentry = SentrySdk.Init(options =>
        {
            options.Dsn = "https://examplePublicKey@o0.ingest.sentry.io/0";
            // When configuring for the first time, to see what the SDK is doing:
            options.Debug = true;
            // Adds request URL and headers, IP and name for users, etc.
            options.SendDefaultPii = true;

            //  performance
            // Set traces_sample_rate to 1.0 to capture 100% of transactions for performance monitoring.
            // We recommend adjusting this value in production.
            options.TracesSampleRate = 1.0;
            //  performance

            // If you also installed the Sentry.EntityFramework package
            options.AddEntityFramework();
            options.AddAspNet();
        });
    }

    // Global error catcher
    protected void Application_Error() => Server.CaptureLastError();

    //  performance
    protected void Application_BeginRequest()
    {
        Context.StartSentryTransaction();
    }

    protected void Application_EndRequest()
    {
        Context.FinishSentryTransaction();
    }
    //  performance

    protected void Application_End()
    {
        // Flushes out events before shutting down.
        _sentry?.Dispose();
    }
}
```

### [Capturing the affected user](https://docs.sentry.io/.md#capturing-the-affected-user)

When opting-in to [SendDefaultPii](https://docs.sentry.io/.md#senddefaultpii), the SDK will automatically read the user from the request by inspecting `HttpContext.User`. Default claim values like `NameIdentifier` for the *Id* will be used.

```csharp
options.AddAspNet();
options.Dsn = "https://examplePublicKey@o0.ingest.sentry.io/0";
// Opt-in to send things like UserId and UserName if a user is logged-in
options.SendDefaultPii = true;
```

### [SendDefaultPii](https://docs.sentry.io/.md#senddefaultpii)

Although this setting is part of the [Sentry](https://docs.sentry.io/platforms/dotnet.md) package, in the context of ASP.NET Core, it means reporting the user by reading the frameworks `HttpContext.User`. The strategy to create the `SentryUser` can be customized.

### [IncludeRequestPayload](https://docs.sentry.io/.md#includerequestpayload)

It's helpful to troubleshoot a problem in the API when the payload that hit the endpoint is logged. Opt-in to send the request body to Sentry:

```csharp
options.AddAspNet(RequestSize.Always);
```

## [Verify](https://docs.sentry.io/.md#verify)

This snippet includes an intentional error, so you can test that everything is working as soon as you set it up.

```csharp
try
{
    throw null;
}
catch (Exception ex)
{
    SentrySdk.CaptureException(ex);
}
```

## [Troubleshooting](https://docs.sentry.io/.md#troubleshooting)

For information about Troubleshooting, please visit the [troubleshooting](https://docs.sentry.io/troubleshooting.md) page.

## [Samples](https://docs.sentry.io/.md#samples)

* A [sample with ASP.NET and EF 6](https://github.com/getsentry/examples/tree/master/dotnet/AspNetMvc5Ef6.md) and additional samples of the [.NET SDKs](https://github.com/getsentry/examples/tree/master/dotnet.md)
