Application Insights for ASP.NET and ASP.NET Core applications

We use an MVC application example. If you're using the Worker Service, use the instructions in Application Insights for Worker Service applications.

1. Open Visual Studio.
2. Select Create a new project.
3. Choose ASP.NET Web Application (.NET Framework) with C# and select Next.
4. Enter a Project name, then select Create.
5. Choose MVC, then select Create.

1. Open Visual Studio.
2. Select Create a new project.
3. Choose ASP.NET Core Web App (Razor Pages) with C# and select Next.
4. Enter a Project name, then select Create.
5. Choose a Framework (LTS or STS), then select Create.

From within your ASP.NET web app project in Visual Studio:

1. Select Project > Add Application Insights Telemetry > Application Insights Sdk (local) > Next > Finish > Close.

2. Open the ApplicationInsights.config file.

3. Before the closing </ApplicationInsights> tag, add a line that contains the connection string for your Application Insights resource. Find your connection string on the overview pane of the newly created Application Insights resource.

   <ConnectionString>Copy connection string from Application Insights Resource Overview</ConnectionString>
   

4. Select Project > Manage NuGet Packages > Updates. Then update each Microsoft.ApplicationInsights NuGet package to the latest stable release.

5. Run your application by selecting IIS Express. A basic ASP.NET app opens. As you browse through the pages on the site, telemetry is sent to Application Insights.

From within your ASP.NET web app project in Visual Studio:

1. Go to Project > Add Application Insights Telemetry.

2. Select Azure Application Insights > Next.

3. Choose your subscription and Application Insights instance. Or you can create a new instance with Create new. Select Next.

4. Add or confirm your Application Insights connection string. It should be prepopulated based on your selection in the previous step. Select Finish.

5. After you add Application Insights to your project, check to confirm that you're using the latest stable release of the SDK. Go to Project > Manage NuGet Packages > Microsoft.ApplicationInsights.AspNetCore. If you need to, select Update.

   

1. Add the following NuGet packages and their dependencies to your project:

   • Microsoft.ApplicationInsights.WindowsServer
   • Microsoft.ApplicationInsights.Web
   • Microsoft.AspNet.TelemetryCorrelation

2. In some cases, the ApplicationInsights.config file is created for you automatically. If the file is already present, skip to step 4.

   Create it yourself if it's missing. In the root directory of an ASP.NET application, create a new file called ApplicationInsights.config.

3. Copy the following XML configuration into your newly created file:

   <?xml version="1.0" encoding="utf-8"?>
   <ApplicationInsights xmlns="http://schemas.microsoft.com/ApplicationInsights/2013/Settings">
     <TelemetryInitializers>
       <Add Type="Microsoft.ApplicationInsights.DependencyCollector.HttpDependenciesParsingTelemetryInitializer, Microsoft.AI.DependencyCollector" />
       <Add Type="Microsoft.ApplicationInsights.WindowsServer.AzureRoleEnvironmentTelemetryInitializer, Microsoft.AI.WindowsServer" />
       <Add Type="Microsoft.ApplicationInsights.WindowsServer.BuildInfoConfigComponentVersionTelemetryInitializer, Microsoft.AI.WindowsServer" />
       <Add Type="Microsoft.ApplicationInsights.Web.WebTestTelemetryInitializer, Microsoft.AI.Web" />
       <Add Type="Microsoft.ApplicationInsights.Web.SyntheticUserAgentTelemetryInitializer, Microsoft.AI.Web">
         <!-- Extended list of bots:
               search|spider|crawl|Bot|Monitor|BrowserMob|BingPreview|PagePeeker|WebThumb|URL2PNG|ZooShot|GomezA|Google SketchUp|Read Later|KTXN|KHTE|Keynote|Pingdom|AlwaysOn|zao|borg|oegp|silk|Xenu|zeal|NING|htdig|lycos|slurp|teoma|voila|yahoo|Sogou|CiBra|Nutch|Java|JNLP|Daumoa|Genieo|ichiro|larbin|pompos|Scrapy|snappy|speedy|vortex|favicon|indexer|Riddler|scooter|scraper|scrubby|WhatWeb|WinHTTP|voyager|archiver|Icarus6j|mogimogi|Netvibes|altavista|charlotte|findlinks|Retreiver|TLSProber|WordPress|wsr-agent|http client|Python-urllib|AppEngine-Google|semanticdiscovery|facebookexternalhit|web/snippet|Google-HTTP-Java-Client-->
         <Filters>search|spider|crawl|Bot|Monitor|AlwaysOn</Filters>
       </Add>
       <Add Type="Microsoft.ApplicationInsights.Web.ClientIpHeaderTelemetryInitializer, Microsoft.AI.Web" />
       <Add Type="Microsoft.ApplicationInsights.Web.AzureAppServiceRoleNameFromHostNameHeaderInitializer, Microsoft.AI.Web" />
       <Add Type="Microsoft.ApplicationInsights.Web.OperationNameTelemetryInitializer, Microsoft.AI.Web" />
       <Add Type="Microsoft.ApplicationInsights.Web.OperationCorrelationTelemetryInitializer, Microsoft.AI.Web" />
       <Add Type="Microsoft.ApplicationInsights.Web.UserTelemetryInitializer, Microsoft.AI.Web" />
       <Add Type="Microsoft.ApplicationInsights.Web.AuthenticatedUserIdTelemetryInitializer, Microsoft.AI.Web" />
       <Add Type="Microsoft.ApplicationInsights.Web.AccountIdTelemetryInitializer, Microsoft.AI.Web" />
       <Add Type="Microsoft.ApplicationInsights.Web.SessionTelemetryInitializer, Microsoft.AI.Web" />
     </TelemetryInitializers>
     <TelemetryModules>
       <Add Type="Microsoft.ApplicationInsights.DependencyCollector.DependencyTrackingTelemetryModule, Microsoft.AI.DependencyCollector">
         <ExcludeComponentCorrelationHttpHeadersOnDomains>
           <!-- 
           Requests to the following hostnames will not be modified by adding correlation headers.
           Add entries here to exclude additional hostnames.
           NOTE: this configuration will be lost upon NuGet upgrade.
           -->
           <Add>core.windows.net</Add>
           <Add>core.chinacloudapi.cn</Add>
           <Add>core.cloudapi.de</Add>
           <Add>core.usgovcloudapi.net</Add>
         </ExcludeComponentCorrelationHttpHeadersOnDomains>
         <IncludeDiagnosticSourceActivities>
           <Add>Microsoft.Azure.EventHubs</Add>
           <Add>Azure.Messaging.ServiceBus</Add>
         </IncludeDiagnosticSourceActivities>
       </Add>
       <Add Type="Microsoft.ApplicationInsights.Extensibility.PerfCounterCollector.PerformanceCollectorModule, Microsoft.AI.PerfCounterCollector">
         <!--
         Use the following syntax here to collect additional performance counters:
   
         <Counters>
           <Add PerformanceCounter="\Process(??APP_WIN32_PROC??)\Handle Count" ReportAs="Process handle count" />
           ...
         </Counters>
   
         PerformanceCounter must be either \CategoryName(InstanceName)\CounterName or \CategoryName\CounterName
   
         NOTE: performance counters configuration will be lost upon NuGet upgrade.
   
         The following placeholders are supported as InstanceName:
           ??APP_WIN32_PROC?? - instance name of the application process  for Win32 counters.
           ??APP_W3SVC_PROC?? - instance name of the application IIS worker process for IIS/ASP.NET counters.
           ??APP_CLR_PROC?? - instance name of the application CLR process for .NET counters.
         -->
       </Add>
       <Add Type="Microsoft.ApplicationInsights.Extensibility.PerfCounterCollector.QuickPulse.QuickPulseTelemetryModule, Microsoft.AI.PerfCounterCollector" />
       <Add Type="Microsoft.ApplicationInsights.WindowsServer.AppServicesHeartbeatTelemetryModule, Microsoft.AI.WindowsServer" />
       <Add Type="Microsoft.ApplicationInsights.WindowsServer.AzureInstanceMetadataTelemetryModule, Microsoft.AI.WindowsServer">
         <!--
         Remove individual fields collected here by adding them to the ApplicationInsighs.HeartbeatProvider
         with the following syntax:
   
         <Add Type="Microsoft.ApplicationInsights.Extensibility.Implementation.Tracing.DiagnosticsTelemetryModule, Microsoft.ApplicationInsights">
           <ExcludedHeartbeatProperties>
             <Add>osType</Add>
             <Add>___location</Add>
             <Add>name</Add>
             <Add>offer</Add>
             <Add>platformFaultDomain</Add>
             <Add>platformUpdateDomain</Add>
             <Add>publisher</Add>
             <Add>sku</Add>
             <Add>version</Add>
             <Add>vmId</Add>
             <Add>vmSize</Add>
             <Add>subscriptionId</Add>
             <Add>resourceGroupName</Add>
             <Add>placementGroupId</Add>
             <Add>tags</Add>
             <Add>vmScaleSetName</Add>
           </ExcludedHeartbeatProperties>
         </Add>
   
         NOTE: exclusions will be lost upon upgrade.
         -->
       </Add>
       <Add Type="Microsoft.ApplicationInsights.WindowsServer.DeveloperModeWithDebuggerAttachedTelemetryModule, Microsoft.AI.WindowsServer" />
       <Add Type="Microsoft.ApplicationInsights.WindowsServer.UnhandledExceptionTelemetryModule, Microsoft.AI.WindowsServer" />
       <Add Type="Microsoft.ApplicationInsights.WindowsServer.UnobservedExceptionTelemetryModule, Microsoft.AI.WindowsServer">
         <!--</Add>
       <Add Type="Microsoft.ApplicationInsights.WindowsServer.FirstChanceExceptionStatisticsTelemetryModule, Microsoft.AI.WindowsServer">-->
       </Add>
       <Add Type="Microsoft.ApplicationInsights.Web.RequestTrackingTelemetryModule, Microsoft.AI.Web">
         <Handlers>
           <!-- 
           Add entries here to filter out additional handlers:
   
           NOTE: handler configuration will be lost upon NuGet upgrade.
           -->
           <Add>Microsoft.VisualStudio.Web.PageInspector.Runtime.Tracing.RequestDataHttpHandler</Add>
           <Add>System.Web.StaticFileHandler</Add>
           <Add>System.Web.Handlers.AssemblyResourceLoader</Add>
           <Add>System.Web.Optimization.BundleHandler</Add>
           <Add>System.Web.Script.Services.ScriptHandlerFactory</Add>
           <Add>System.Web.Handlers.TraceHandler</Add>
           <Add>System.Web.Services.Discovery.DiscoveryRequestHandler</Add>
           <Add>System.Web.HttpDebugHandler</Add>
         </Handlers>
       </Add>
       <Add Type="Microsoft.ApplicationInsights.Web.ExceptionTrackingTelemetryModule, Microsoft.AI.Web" />
       <Add Type="Microsoft.ApplicationInsights.Web.AspNetDiagnosticTelemetryModule, Microsoft.AI.Web" />
     </TelemetryModules>
     <ApplicationIdProvider Type="Microsoft.ApplicationInsights.Extensibility.Implementation.ApplicationId.ApplicationInsightsApplicationIdProvider, Microsoft.ApplicationInsights" />
     <TelemetrySinks>
       <Add Name="default">
         <TelemetryProcessors>
           <Add Type="Microsoft.ApplicationInsights.Extensibility.PerfCounterCollector.QuickPulse.QuickPulseTelemetryProcessor, Microsoft.AI.PerfCounterCollector" />
           <Add Type="Microsoft.ApplicationInsights.Extensibility.AutocollectedMetricsExtractor, Microsoft.ApplicationInsights" />
           <Add Type="Microsoft.ApplicationInsights.WindowsServer.TelemetryChannel.AdaptiveSamplingTelemetryProcessor, Microsoft.AI.ServerTelemetryChannel">
             <MaxTelemetryItemsPerSecond>5</MaxTelemetryItemsPerSecond>
             <ExcludedTypes>Event</ExcludedTypes>
           </Add>
           <Add Type="Microsoft.ApplicationInsights.WindowsServer.TelemetryChannel.AdaptiveSamplingTelemetryProcessor, Microsoft.AI.ServerTelemetryChannel">
             <MaxTelemetryItemsPerSecond>5</MaxTelemetryItemsPerSecond>
             <IncludedTypes>Event</IncludedTypes>
           </Add>
           <!--
             Adjust the include and exclude examples to specify the desired semicolon-delimited types. (Dependency, Event, Exception, PageView, Request, Trace)
           -->
         </TelemetryProcessors>
         <TelemetryChannel Type="Microsoft.ApplicationInsights.WindowsServer.TelemetryChannel.ServerTelemetryChannel, Microsoft.AI.ServerTelemetryChannel" />
       </Add>
     </TelemetrySinks>
     <!-- 
       Learn more about Application Insights configuration with ApplicationInsights.config here:
       http://go.microsoft.com/fwlink/?LinkID=513840
     -->
     <ConnectionString>Copy the connection string from your Application Insights resource</ConnectionString>
   </ApplicationInsights>
   

4. Add the connection string, which can be done in two ways:

   • (Recommended) Set the connection string in configuration.

     Before the closing </ApplicationInsights> tag in ApplicationInsights.config, add the connection string for your Application Insights resource. You can find your connection string on the overview pane of the newly created Application Insights resource.

     <ConnectionString>Copy the connection string from your Application Insights resource</ConnectionString>
     

   • Set the connection string in code.

     Provide a connection string in your program.cs class.

     var configuration = new TelemetryConfiguration
     {
         ConnectionString = "Copy the connection string from your Application Insights resource"
     };
     

5. At the same level of your project as the ApplicationInsights.config file, create a folder called ErrorHandler with a new C# file called AiHandleErrorAttribute.cs. The contents of the file look like this:

   using System;
   using System.Web.Mvc;
   using Microsoft.ApplicationInsights;
   
   namespace WebApplication10.ErrorHandler //namespace will vary based on your project name
   {
       [AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, Inherited = true, AllowMultiple = true)] 
       public class AiHandleErrorAttribute : HandleErrorAttribute
       {
           public override void OnException(ExceptionContext filterContext)
           {
               if (filterContext != null && filterContext.HttpContext != null && filterContext.Exception != null)
               {
                   //If customError is Off, then AI HTTPModule will report the exception
                   if (filterContext.HttpContext.IsCustomErrorEnabled)
                   {   
                       var ai = new TelemetryClient();
                       ai.TrackException(filterContext.Exception);
                   } 
               }
               base.OnException(filterContext);
           }
       }
   }
   

6. In the App_Start folder, open the FilterConfig.cs file and change it to match the sample:

   using System.Web;
   using System.Web.Mvc;
   
   namespace WebApplication10 //Namespace will vary based on project name
   {
       public class FilterConfig
       {
           public static void RegisterGlobalFilters(GlobalFilterCollection filters)
           {
               filters.Add(new ErrorHandler.AiHandleErrorAttribute());
           }
       }
   }
   

7. If Web.config is already updated, skip this step. Otherwise, update the file as follows:

   <?xml version="1.0" encoding="utf-8"?>
   <!--
     For more information on how to configure your ASP.NET application, please visit
     https://go.microsoft.com/fwlink/?LinkId=301880
     -->
   <configuration>
     <appSettings>
       <add key="webpages:Version" value="3.0.0.0" />
       <add key="webpages:Enabled" value="false" />
       <add key="ClientValidationEnabled" value="true" />
       <add key="UnobtrusiveJavaScriptEnabled" value="true" />
     </appSettings>
     <system.web>
       <compilation debug="true" targetFramework="4.7.2" />
       <httpRuntime targetFramework="4.7.2" />
       <!-- Code added for Application Insights start -->
       <httpModules>
         <add name="TelemetryCorrelationHttpModule" type="Microsoft.AspNet.TelemetryCorrelation.TelemetryCorrelationHttpModule, Microsoft.AspNet.TelemetryCorrelation" />
         <add name="ApplicationInsightsWebTracking" type="Microsoft.ApplicationInsights.Web.ApplicationInsightsHttpModule, Microsoft.AI.Web" />
       </httpModules>
       <!-- Code added for Application Insights end -->
     </system.web>
     <runtime>
       <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
         <dependentAssembly>
           <assemblyIdentity name="Antlr3.Runtime" publicKeyToken="eb42632606e9261f" />
           <bindingRedirect oldVersion="0.0.0.0-3.5.0.2" newVersion="3.5.0.2" />
         </dependentAssembly>
         <dependentAssembly>
           <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" />
           <bindingRedirect oldVersion="0.0.0.0-12.0.0.0" newVersion="12.0.0.0" />
         </dependentAssembly>
         <dependentAssembly>
           <assemblyIdentity name="System.Web.Optimization" publicKeyToken="31bf3856ad364e35" />
           <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="1.1.0.0" />
         </dependentAssembly>
         <dependentAssembly>
           <assemblyIdentity name="WebGrease" publicKeyToken="31bf3856ad364e35" />
           <bindingRedirect oldVersion="0.0.0.0-1.6.5135.21930" newVersion="1.6.5135.21930" />
         </dependentAssembly>
         <dependentAssembly>
           <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
           <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
         </dependentAssembly>
         <dependentAssembly>
           <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35" />
           <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
         </dependentAssembly>
         <dependentAssembly>
           <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />
           <bindingRedirect oldVersion="1.0.0.0-5.2.7.0" newVersion="5.2.7.0" />
         </dependentAssembly>
         <!-- Code added for Application Insights start -->
         <dependentAssembly>
           <assemblyIdentity name="System.Memory" publicKeyToken="cc7b13ffcd2ddd51" culture="neutral" />
           <bindingRedirect oldVersion="0.0.0.0-4.0.1.1" newVersion="4.0.1.1" />
         </dependentAssembly>
         <!-- Code added for Application Insights end -->
       </assemblyBinding>
     </runtime>
     <system.codedom>
       <compilers>
         <compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=2.0.1.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:default /nowarn:1659;1699;1701" />
         <compiler language="vb;vbs;visualbasic;vbscript" extension=".vb" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.VBCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=2.0.1.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:default /nowarn:41008 /define:_MYTYPE=\&quot;Web\&quot; /optionInfer+" />
       </compilers>
     </system.codedom>
     <system.webServer>
       <validation validateIntegratedModeConfiguration="false" />
       <!-- Code added for Application Insights start -->
       <modules>
         <remove name="TelemetryCorrelationHttpModule" />
         <add name="TelemetryCorrelationHttpModule" type="Microsoft.AspNet.TelemetryCorrelation.TelemetryCorrelationHttpModule, Microsoft.AspNet.TelemetryCorrelation" preCondition="managedHandler" />
         <remove name="ApplicationInsightsWebTracking" />
         <add name="ApplicationInsightsWebTracking" type="Microsoft.ApplicationInsights.Web.ApplicationInsightsHttpModule, Microsoft.AI.Web" preCondition="managedHandler" />
       </modules>
       <!-- Code added for Application Insights end -->
     </system.webServer>
   </configuration>
   

At this point, you successfully configured server-side application monitoring. If you run your web app, you see telemetry begin to appear in Application Insights.

1. Install the Application Insights SDK NuGet package for ASP.NET Core.

   We recommend that you always use the latest stable version. Find full release notes for the SDK on the open-source GitHub repo.

   The following code sample shows the changes to add to your project's .csproj file:

   <ItemGroup>
       <PackageReference Include="Microsoft.ApplicationInsights.AspNetCore" Version="2.21.0" />
   </ItemGroup>
   

2. Add AddApplicationInsightsTelemetry() to your program.cs class.

   Add builder.Services.AddApplicationInsightsTelemetry(); after the WebApplication.CreateBuilder() method, as in this example:

   // This method gets called by the runtime. Use this method to add services to the container.
   var builder = WebApplication.CreateBuilder(args);
   
   // The following line enables Application Insights telemetry collection.
   builder.Services.AddApplicationInsightsTelemetry();
   
   // This code adds other services for your application.
   builder.Services.AddMvc();
   
   var app = builder.Build();
   

3. Add the connection string, which can be done in three ways:

   • (Recommended) Set the connection string in configuration.

     Set the connection string in appsettings.json and make sure the configuration file is copied to the application root folder during publishing.

     {
         "Logging": {
             "LogLevel": {
                 "Default": "Information",
                 "Microsoft.AspNetCore": "Warning"
             }
         },
         "AllowedHosts": "*",
         "ApplicationInsights": {
             "ConnectionString": "InstrumentationKey=00000000-0000-0000-0000-000000000000"
         }
     }
     

   • Set the connection string in the APPLICATIONINSIGHTS_CONNECTION_STRING environment variable or ApplicationInsights:ConnectionString in the JSON configuration file.

     For example:

     • SET ApplicationInsights:ConnectionString = <Copy connection string from Application Insights Resource Overview>
     • SET APPLICATIONINSIGHTS_CONNECTION_STRING = <Copy connection string from Application Insights Resource Overview>
     • Typically, APPLICATIONINSIGHTS_CONNECTION_STRING is used in Web Apps. It can also be used in all places where this SDK is supported.

     Note

     A connection string specified in code wins over the environment variable APPLICATIONINSIGHTS_CONNECTION_STRING, which wins over other options.

   • Set the connection string in code.

     Provide a connection string as part of the ApplicationInsightsServiceOptions argument to AddApplicationInsightsTelemetry in your program.cs class.

User secrets and other configuration providers

If you want to store the connection string in ASP.NET Core user secrets or retrieve it from another configuration provider, you can use the overload with a Microsoft.Extensions.Configuration.IConfiguration parameter. An example parameter is services.AddApplicationInsightsTelemetry(Configuration);.

In Microsoft.ApplicationInsights.AspNetCore version 2.15.0 and later, calling services.AddApplicationInsightsTelemetry() automatically reads the connection string from Microsoft.Extensions.Configuration.IConfiguration of the application. There's no need to explicitly provide IConfiguration.

If IConfiguration has loaded configuration from multiple providers, then services.AddApplicationInsightsTelemetry prioritizes configuration from appsettings.json, irrespective of the order in which providers are added. Use the services.AddApplicationInsightsTelemetry(IConfiguration) method to read configuration from IConfiguration without this preferential treatment for appsettings.json.

To manually configure live metrics:

1. Install the NuGet package Microsoft.ApplicationInsights.PerfCounterCollector.

2. The following sample console app code shows setting up live metrics:

using Microsoft.ApplicationInsights;
using Microsoft.ApplicationInsights.Extensibility;
using Microsoft.ApplicationInsights.Extensibility.PerfCounterCollector.QuickPulse;
using System;
using System.Threading.Tasks;

namespace LiveMetricsDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            // Create a TelemetryConfiguration instance.
            TelemetryConfiguration config = TelemetryConfiguration.CreateDefault();
            config.InstrumentationKey = "INSTRUMENTATION-KEY-HERE";
            QuickPulseTelemetryProcessor quickPulseProcessor = null;
            config.DefaultTelemetrySink.TelemetryProcessorChainBuilder
                .Use((next) =>
                {
                    quickPulseProcessor = new QuickPulseTelemetryProcessor(next);
                    return quickPulseProcessor;
                })
                .Build();

            var quickPulseModule = new QuickPulseTelemetryModule();

            // Secure the control channel.
            // This is optional, but recommended.
            quickPulseModule.AuthenticationApiKey = "YOUR-API-KEY-HERE";
            quickPulseModule.Initialize(config);
            quickPulseModule.RegisterTelemetryProcessor(quickPulseProcessor);

            // Create a TelemetryClient instance. It is important
            // to use the same TelemetryConfiguration here as the one
            // used to set up live metrics.
            TelemetryClient client = new TelemetryClient(config);

            // This sample runs indefinitely. Replace with actual application logic.
            while (true)
            {
                // Send dependency and request telemetry.
                // These will be shown in live metrics.
                // CPU/Memory Performance counter is also shown
                // automatically without any additional steps.
                client.TrackDependency("My dependency", "target", "http://sample",
                    DateTimeOffset.Now, TimeSpan.FromMilliseconds(300), true);
                client.TrackRequest("My Request", DateTimeOffset.Now,
                    TimeSpan.FromMilliseconds(230), "200", true);
                Task.Delay(1000).Wait();
            }
        }
    }
}

To manually configure live metrics:

1. Install the NuGet package Microsoft.ApplicationInsights.PerfCounterCollector.

2. The following sample console app code shows setting up live metrics:

using Microsoft.ApplicationInsights;
using Microsoft.ApplicationInsights.Extensibility;
using Microsoft.ApplicationInsights.Extensibility.PerfCounterCollector.QuickPulse;

// Create a TelemetryConfiguration instance.
TelemetryConfiguration config = TelemetryConfiguration.CreateDefault();
config.ConnectionString = "InstrumentationKey=00000000-0000-0000-0000-000000000000";
QuickPulseTelemetryProcessor quickPulseProcessor = null;
config.DefaultTelemetrySink.TelemetryProcessorChainBuilder
    .Use((next) =>
    {
        quickPulseProcessor = new QuickPulseTelemetryProcessor(next);
        return quickPulseProcessor;
    })
    .Build();

var quickPulseModule = new QuickPulseTelemetryModule();

// Secure the control channel.
// This is optional, but recommended.
quickPulseModule.AuthenticationApiKey = "YOUR-API-KEY-HERE";
quickPulseModule.Initialize(config);
quickPulseModule.RegisterTelemetryProcessor(quickPulseProcessor);

// Create a TelemetryClient instance. It is important
// to use the same TelemetryConfiguration here as the one
// used to set up live metrics.
TelemetryClient client = new TelemetryClient(config);

// This sample runs indefinitely. Replace with actual application logic.
while (true)
{
    // Send dependency and request telemetry.
    // These will be shown in live metrics.
    // CPU/Memory Performance counter is also shown
    // automatically without any additional steps.
    client.TrackDependency("My dependency", "target", "http://sample",
        DateTimeOffset.Now, TimeSpan.FromMilliseconds(300), true);
    client.TrackRequest("My Request", DateTimeOffset.Now,
        TimeSpan.FromMilliseconds(230), "200", true);
    Task.Delay(1000).Wait();
}

The preceding sample is for a console app, but the same code can be used in any .NET applications.

var requestTelemetry = HttpContext.Current?.Items["Microsoft.ApplicationInsights.RequestTelemetry"] as RequestTelemetry;

if (requestTelemetry != null)
{
    requestTelemetry.Properties["myProp"] = "someData";
}

HttpContext.Features.Get<RequestTelemetry>().Properties["myProp"] = someData

To learn how to configure the Application Insights SDK for ASP.NET applications, see Configure the Application Insights SDK with ApplicationInsights.config or .xml.

In ASP.NET Core applications, all configuration changes are made in the ConfigureServices() method of your Startup.cs class, unless otherwise directed.

Use ApplicationInsightsServiceOptions

You can modify a few common settings by passing ApplicationInsightsServiceOptions to AddApplicationInsightsTelemetry, as in this example:

var builder = WebApplication.CreateBuilder(args);

var aiOptions = new Microsoft.ApplicationInsights.AspNetCore.Extensions.ApplicationInsightsServiceOptions();

// Disables adaptive sampling.
aiOptions.EnableAdaptiveSampling = false;

// Disables live metrics (also known as QuickPulse).
aiOptions.EnableQuickPulseMetricStream = false;

builder.Services.AddApplicationInsightsTelemetry(aiOptions);
var app = builder.Build();

This table has the full list of ApplicationInsightsServiceOptions settings:

For the most current list, see the configurable settings in ApplicationInsightsServiceOptions.

Configuration recommendation for Microsoft.ApplicationInsights.AspNetCore SDK 2.15.0 and later

In Microsoft.ApplicationInsights.AspNetCore SDK version 2.15.0 and later, configure every setting available in ApplicationInsightsServiceOptions, including ConnectionString. Use the application's IConfiguration instance. The settings must be under the section ApplicationInsights, as shown in the following example. The following section from appsettings.json configures the connection string and disables adaptive sampling and performance counter collection.

{
    "ApplicationInsights": {
    "ConnectionString": "InstrumentationKey=00000000-0000-0000-0000-000000000000",
    "EnableAdaptiveSampling": false,
    "EnablePerformanceCounterCollectionModule": false
    }
}

If builder.Services.AddApplicationInsightsTelemetry(aiOptions) for ASP.NET Core 6.0 or services.AddApplicationInsightsTelemetry(aiOptions) for ASP.NET Core 3.1 and earlier is used, it overrides the settings from Microsoft.Extensions.Configuration.IConfiguration.

To learn how to configure sampling for ASP.NET applications, see Sampling in Application Insights.

The Application Insights SDK for ASP.NET Core supports both fixed-rate and adaptive sampling. By default, adaptive sampling is enabled.

For more information, see Sampling in Application Insights.

To learn how to use telemetry initializers with ASP.NET applications, see Filter and preprocess telemetry in the Application Insights SDK.

Add telemetry initializers

Add any new TelemetryInitializer to the DependencyInjection container as shown in the following code. The SDK automatically picks up any TelemetryInitializer that's added to the DependencyInjection container.

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddSingleton<ITelemetryInitializer, MyCustomTelemetryInitializer>();

var app = builder.Build();

Remove telemetry initializers

By default, telemetry initializers are present. To remove all or specific telemetry initializers, use the following sample code after calling AddApplicationInsightsTelemetry().

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddApplicationInsightsTelemetry();

// Remove a specific built-in telemetry initializer
var tiToRemove = builder.Services.FirstOrDefault<ServiceDescriptor>
                    (t => t.ImplementationType == typeof(AspNetCoreEnvironmentTelemetryInitializer));
if (tiToRemove != null)
{
    builder.Services.Remove(tiToRemove);
}

// Remove all initializers
// This requires importing namespace by using Microsoft.Extensions.DependencyInjection.Extensions;
builder.Services.RemoveAll(typeof(ITelemetryInitializer));

var app = builder.Build();

To learn how to use telemetry processors with ASP.NET applications, see Filter and preprocess telemetry in the Application Insights SDK.

Add telemetry processors

You can add custom telemetry processors to TelemetryConfiguration by using the extension method AddApplicationInsightsTelemetryProcessor on IServiceCollection. You use telemetry processors in advanced filtering scenarios. Use the following example:

var builder = WebApplication.CreateBuilder(args);

// ...
builder.Services.AddApplicationInsightsTelemetry();
builder.Services.AddApplicationInsightsTelemetryProcessor<MyFirstCustomTelemetryProcessor>();

// If you have more processors:
builder.Services.AddApplicationInsightsTelemetryProcessor<MySecondCustomTelemetryProcessor>();

var app = builder.Build();

To learn how to configure or remove telemetry modules for ASP.NET application, see Configure the Application Insights SDK with ApplicationInsights.config or .xml.

To configure any default TelemetryModule, use the extension method ConfigureTelemetryModule<T> on IServiceCollection, as shown in the following example:

using Microsoft.ApplicationInsights.DependencyCollector;
using Microsoft.ApplicationInsights.Extensibility.PerfCounterCollector;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddApplicationInsightsTelemetry();

// The following configures DependencyTrackingTelemetryModule.
// Similarly, any other default modules can be configured.
builder.Services.ConfigureTelemetryModule<DependencyTrackingTelemetryModule>((module, o) =>
        {
            module.EnableW3CHeadersInjection = true;
        });

// The following removes all default counters from EventCounterCollectionModule, and adds a single one.
builder.Services.ConfigureTelemetryModule<EventCounterCollectionModule>((module, o) =>
        {
            module.Counters.Add(new EventCounterCollectionRequest("System.Runtime", "gen-0-size"));
        });

// The following removes PerformanceCollectorModule to disable perf-counter collection.
// Similarly, any other default modules can be removed.
var performanceCounterService = builder.Services.FirstOrDefault<ServiceDescriptor>(t => t.ImplementationType == typeof(PerformanceCollectorModule));
if (performanceCounterService != null)
{
    builder.Services.Remove(performanceCounterService);
}

var app = builder.Build();

In versions 2.12.2 and later, ApplicationInsightsServiceOptions includes an easy option to disable any of the default modules.

Configure a telemetry channel

The default telemetry channel is ServerTelemetryChannel. The following example shows how to override it.

using Microsoft.ApplicationInsights.Channel;

var builder = WebApplication.CreateBuilder(args);

// Use the following to replace the default channel with InMemoryChannel.
// This can also be applied to ServerTelemetryChannel.
builder.Services.AddSingleton(typeof(ITelemetryChannel), new InMemoryChannel() {MaxTelemetryBufferCapacity = 19898 });

builder.Services.AddApplicationInsightsTelemetry();

var app = builder.Build();

Disable telemetry dynamically

If you want to disable telemetry conditionally and dynamically, you can resolve the TelemetryConfiguration instance with an ASP.NET Core dependency injection container anywhere in your code and set the DisableTelemetry flag on it.

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddApplicationInsightsTelemetry();

// any custom configuration can be done here:
builder.Services.Configure<TelemetryConfiguration>(x => x.DisableTelemetry = true);

var app = builder.Build();

The preceding code sample prevents the sending of telemetry to Application Insights. It doesn't prevent any automatic collection modules from collecting telemetry. If you want to remove a particular autocollection module, see Remove the telemetry module.

For the template-based ASP.NET MVC app from this article, the file that you need to edit is _Layout.cshtml. You can find it under Views > Shared. To add client-side monitoring, open _Layout.cshtml and follow the JavaScript (Web) SDK Loader Script-based setup instructions from the article about client-side JavaScript SDK configuration.

If your application has client-side components, follow the next steps to start collecting usage telemetry using JavaScript (Web) SDK Loader Script injection by configuration.

1. In _ViewImports.cshtml, add injection:

   @inject Microsoft.ApplicationInsights.AspNetCore.JavaScriptSnippet JavaScriptSnippet
   

2. In _Layout.cshtml, insert HtmlHelper at the end of the <head> section but before any other script. If you want to report any custom JavaScript telemetry from the page, inject it after this snippet:

       @Html.Raw(JavaScriptSnippet.FullScript)
   </head>
   

As an alternative to using FullScript, ScriptBody is available starting in Application Insights SDK for ASP.NET Core version 2.14. Use ScriptBody if you need to control the <script> tag to set a Content Security Policy:

<script> // apply custom changes to this script tag.
    @Html.Raw(JavaScriptSnippet.ScriptBody)
</script>

The .cshtml file names referenced earlier are from a default MVC application template. Ultimately, if you want to properly enable client-side monitoring for your application, the JavaScript (Web) SDK Loader Script must appear in the <head> section of each page of your application that you want to monitor. Add the JavaScript (Web) SDK Loader Script to _Layout.cshtml in an application template to enable client-side monitoring.

If your project doesn't include _Layout.cshtml, you can still add client-side monitoring by adding the JavaScript (Web) SDK Loader Script to an equivalent file that controls the <head> of all pages within your app. Alternatively, you can add the JavaScript (Web) SDK Loader Script to multiple pages, but we don't recommend it.

• To review frequently asked questions (FAQ), see Applications Insights for ASP.NET FAQ.

• To review frequently asked questions (FAQ), see Application Insights for ASP.NET Core FAQ.
• Learn about dependency injection in ASP.NET Core.