Add GenAI main agent attribution processors for spans and logs

sdk/monitor/Azure.Monitor.OpenTelemetry.AspNetCore/src/Azure.Monitor.OpenTelemetry.AspNetCore.csproj

@@ -24,10 +24,10 @@
     <!-- Depending on monthly deliverables, we may switch between PackageReference or ProjectReference. Keeping both here to make the switch easier. -->
 
     <!-- FOR PUBLIC RELEASES, MUST USE PackageReference. THIS REQUIRES A STAGGERED RELEASE IF SHIPPING A NEW EXPORTER. -->
-    <PackageReference Include="Azure.Monitor.OpenTelemetry.Exporter" />
+    <!-- <PackageReference Include="Azure.Monitor.OpenTelemetry.Exporter" /> -->
 
     <!-- FOR LOCAL DEV, ProjectReference IS PREFERRED. -->
-    <!-- <ProjectReference Include="..\..\Azure.Monitor.OpenTelemetry.Exporter\src\Azure.Monitor.OpenTelemetry.Exporter.csproj" /> -->
+    <ProjectReference Include="..\..\Azure.Monitor.OpenTelemetry.Exporter\src\Azure.Monitor.OpenTelemetry.Exporter.csproj" />
   </ItemGroup>
 
   <!-- Shared sources from Azure.Core -->

sdk/monitor/Azure.Monitor.OpenTelemetry.AspNetCore/tests/Azure.Monitor.OpenTelemetry.AspNetCore.Tests/InitializationTests.cs

@@ -276,6 +276,7 @@ private class TracerProviderVariables
                 public bool foundAzureMonitorTraceExporter;
                 public bool foundLiveMetricsProcessor;
                 public bool foundStandardMetricsExtractionProcessor;
+                public bool foundMainAgentAttributionSpanProcessor;
             }
 
             public static void EvaluateTracerProvider(IServiceProvider serviceProvider, bool expectedLiveMetricsProcessor, bool expectedProfilingSessionTraceProcessor, bool hasInstrumentations)
@@ -298,6 +299,7 @@ public static void EvaluateTracerProvider(IServiceProvider serviceProvider, bool
                 Assert.True(variables.foundStandardMetricsExtractionProcessor);
                 Assert.True(variables.foundAzureMonitorTraceExporter);
                 Assert.Equal(expectedProfilingSessionTraceProcessor, variables.foundProfilingSessionTraceProcessor);
+                Assert.True(variables.foundMainAgentAttributionSpanProcessor);
 
                 // Validate Sampler
                 // The default TracesPerSecond is 5.0, so we expect RateLimitedSampler by default
@@ -379,45 +381,65 @@ public static void EvaluateLoggerProvider(IServiceProvider serviceProvider, bool
                 var processor = processorProperty.GetValue(loggerProvider);
                 Assert.NotNull(processor);
 
-                if (liveMetricsEnabled)
-                {
-                    // When LiveMetrics is enabled, processor should be a CompositeProcessor
-                    Assert.Contains("CompositeProcessor", processor.GetType().Name);
+                // Walk the processor chain to find expected processors.
+                bool foundMainAgentAttributionLogProcessor = false;
+                bool foundLiveMetricsLogProcessor = false;
+                bool foundAzureMonitorLogExporter = false;
 
-                    // Get the first processor (LiveMetricsLogProcessor)
-                    var headField = processor.GetType().GetField("Head", BindingFlags.NonPublic | BindingFlags.Instance);
-                    Assert.NotNull(headField);
-                    var firstNode = headField.GetValue(processor);
-                    Assert.NotNull(firstNode);
+                WalkLogProcessorChain(processor, ref foundMainAgentAttributionLogProcessor, ref foundLiveMetricsLogProcessor, ref foundAzureMonitorLogExporter);
 
-                    var valueField = firstNode.GetType().GetField("Value", BindingFlags.Public | BindingFlags.Instance);
-                    var firstProcessor = valueField!.GetValue(firstNode);
-                    Assert.NotNull(firstProcessor);
-                    Assert.Contains(nameof(LiveMetrics.LiveMetricsLogProcessor), firstProcessor.GetType().Name);
+                Assert.True(foundMainAgentAttributionLogProcessor, "MainAgentAttributionLogProcessor not found");
+                Assert.True(foundAzureMonitorLogExporter, "AzureMonitorLogExporter not found");
+                Assert.Equal(liveMetricsEnabled, foundLiveMetricsLogProcessor);
+            }
 
-                    // Get the second processor (BatchLogRecordExportProcessor & AzureMonitorLogExporter)
-                    var nextProperty = firstNode.GetType().GetProperty("Next", BindingFlags.Public | BindingFlags.Instance);
-                    var secondNode = nextProperty!.GetValue(firstNode);
-                    Assert.NotNull(secondNode);
+            private static void WalkLogProcessorChain(object processor, ref bool foundMainAgent, ref bool foundLiveMetrics, ref bool foundExporter)
+            {
+                var processorType = processor.GetType();
 
-                    var secondProcessor = valueField.GetValue(secondNode);
-                    Assert.NotNull(secondProcessor);
+                if (processorType.Name.Contains("MainAgentAttributionLogProcessor"))
+                {
+                    foundMainAgent = true;
+                    return;
+                }
+                else if (processorType.Name.Contains(nameof(LiveMetrics.LiveMetricsLogProcessor)))
+                {
+                    foundLiveMetrics = true;
+                    return;
+                }
+                else if (processorType.Name.Contains("CompositeProcessor"))
+                {
+                    // Walk the linked list inside the CompositeProcessor
+                    var headField = processorType.GetField("Head", BindingFlags.NonPublic | BindingFlags.Instance);
+                    Assert.NotNull(headField);
+                    var currentNode = headField.GetValue(processor);
 
-                    var exporterProperty = secondProcessor.GetType().GetProperty("Exporter", BindingFlags.NonPublic | BindingFlags.Instance);
-                    Assert.NotNull(exporterProperty);
+                    while (currentNode != null)
+                    {
+                        var valueField = currentNode.GetType().GetField("Value", BindingFlags.Public | BindingFlags.Instance);
+                        var nextProperty = currentNode.GetType().GetProperty("Next", BindingFlags.Public | BindingFlags.Instance);
 
-                    var exporter = exporterProperty.GetValue(secondProcessor);
-                    Assert.NotNull(exporter);
-                    Assert.Contains(nameof(AzureMonitorLogExporter), exporter.GetType().Name);
+                        var childProcessor = valueField!.GetValue(currentNode);
+                        if (childProcessor != null)
+                        {
+                            WalkLogProcessorChain(childProcessor, ref foundMainAgent, ref foundLiveMetrics, ref foundExporter);
+                        }
+
+                        currentNode = nextProperty!.GetValue(currentNode);
+                    }
+
+                    return;
                 }
-                else
-                {
-                    var exporterProperty = processor.GetType().GetProperty("Exporter", BindingFlags.NonPublic | BindingFlags.Instance);
-                    Assert.NotNull(exporterProperty);
 
+                // Check if this processor wraps an exporter
+                var exporterProperty = processorType.GetProperty("Exporter", BindingFlags.NonPublic | BindingFlags.Instance);
+                if (exporterProperty != null)
+                {
                     var exporter = exporterProperty.GetValue(processor);
-                    Assert.NotNull(exporter);
-                    Assert.Contains(nameof(AzureMonitorLogExporter), exporter.GetType().Name);
+                    if (exporter != null && exporter.GetType().Name.Contains(nameof(AzureMonitorLogExporter)))
+                    {
+                        foundExporter = true;
+                    }
                 }
             }
 
@@ -446,6 +468,10 @@ private static void WalkTracerCompositeProcessor(object compositeProcessor, Trac
                         {
                             variables.foundProfilingSessionTraceProcessor = true;
                         }
+                        else if (processorType.Name.Contains("MainAgentAttributionSpanProcessor"))
+                        {
+                            variables.foundMainAgentAttributionSpanProcessor = true;
+                        }
                         else if (processorType.Name.Contains(nameof(LiveMetrics.LiveMetricsActivityProcessor)))
                         {
                             variables.foundLiveMetricsProcessor = true;

sdk/monitor/Azure.Monitor.OpenTelemetry.Exporter/CHANGELOG.md

@@ -4,6 +4,9 @@
 
 ### Features Added
 
+- Added GenAI main agent attribution support. Automatically propagates `microsoft.gen_ai.main_agent.*` attributes from parent spans to child spans and log records, enabling end-to-end tracing of AI agent orchestration.
+  ([#59368](https://github.com/Azure/azure-sdk-for-net/pull/59368))
+
 ### Breaking Changes
 
 ### Bugs Fixed

sdk/monitor/Azure.Monitor.OpenTelemetry.Exporter/src/AzureMonitorExporterExtensions.cs

@@ -8,6 +8,7 @@
 using Azure.Core;
 using Azure.Monitor.OpenTelemetry.Exporter.Internals;
 using Azure.Monitor.OpenTelemetry.Exporter.Internals.Diagnostics;
+using Azure.Monitor.OpenTelemetry.Exporter.Internals.GenAI;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Options;
@@ -94,6 +95,7 @@ public static TracerProviderBuilder AddAzureMonitorTraceExporter(
 
                 sp.EnsureNoUseAzureMonitorExporterRegistrations();
 
+                builder.AddProcessor(new MainAgentAttributionSpanProcessor());
                 builder.AddProcessor(new CompositeProcessor<Activity>(new BaseProcessor<Activity>[]
                 {
                     new StandardMetricsExtractionProcessor(new AzureMonitorMetricExporter(exporterOptions), exporterOptions),
@@ -208,6 +210,7 @@ public static OpenTelemetryLoggerOptions AddAzureMonitorLogExporter(
                 ? new LogFilteringProcessor(exporter)
                 : new BatchLogRecordExportProcessor(exporter);
 
+            loggerOptions.AddProcessor(new MainAgentAttributionLogProcessor());
             return loggerOptions.AddProcessor(processor);
         }
 
@@ -277,9 +280,15 @@ public static LoggerProviderBuilder AddAzureMonitorLogExporter(
 
                 // TODO: Do we need provide an option to alter BatchExportLogRecordProcessorOptions?
                 var exporter = new AzureMonitorLogExporter(exporterOptions);
-                return exporterOptions.EnableTraceBasedLogsSampler
+                BaseProcessor<LogRecord> exportProcessor = exporterOptions.EnableTraceBasedLogsSampler
                     ? new LogFilteringProcessor(exporter)
                     : new BatchLogRecordExportProcessor(exporter);
+
+                return new CompositeProcessor<LogRecord>(new BaseProcessor<LogRecord>[]
+                {
+                    new MainAgentAttributionLogProcessor(),
+                    exportProcessor
+                });
             });
         }
     }

sdk/monitor/Azure.Monitor.OpenTelemetry.Exporter/src/ExporterRegistrationHostedService.cs

@@ -6,6 +6,7 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Azure.Monitor.OpenTelemetry.Exporter.Internals;
+using Azure.Monitor.OpenTelemetry.Exporter.Internals.GenAI;
 using Azure.Monitor.OpenTelemetry.LiveMetrics;
 using Azure.Monitor.OpenTelemetry.LiveMetrics.Internals;
 using Microsoft.Extensions.DependencyInjection;
@@ -66,6 +67,7 @@ private static void Initialize(IServiceProvider serviceProvider)
                 }
 
                 // TODO: Add Ai Sampler.
+                tracerProvider.AddProcessor(new MainAgentAttributionSpanProcessor());
                 tracerProvider.AddProcessor(new CompositeProcessor<Activity>(new BaseProcessor<Activity>[]
                 {
                     new StandardMetricsExtractionProcessor(new AzureMonitorMetricExporter(exporterOptions), exporterOptions),
@@ -87,6 +89,8 @@ private static void Initialize(IServiceProvider serviceProvider)
                                                             ? new LogFilteringProcessor(exporter)
                                                             : new BatchLogRecordExportProcessor(exporter);
 
+                loggerProvider.AddProcessor(new MainAgentAttributionLogProcessor());
+
                 if (exporterOptions.EnableLiveMetrics)
                 {
                     var manager = serviceProvider!.GetRequiredService<LiveMetricsClientManager>();

sdk/monitor/Azure.Monitor.OpenTelemetry.Exporter/src/Internals/GenAI/MainAgentAttributeConstants.cs

@@ -0,0 +1,24 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+namespace Azure.Monitor.OpenTelemetry.Exporter.Internals.GenAI
+{
+    internal static class MainAgentAttributeConstants
+    {
+        // Target attributes (microsoft.gen_ai.main_agent.*)
+        internal const string MainAgentName = "microsoft.gen_ai.main_agent.name";
+        internal const string MainAgentId = "microsoft.gen_ai.main_agent.id";
+        internal const string MainAgentVersion = "microsoft.gen_ai.main_agent.version";
+        internal const string MainAgentConversationId = "microsoft.gen_ai.main_agent.conversation_id";
+
+        // Source / fallback attributes (gen_ai.agent.* / gen_ai.conversation.*)
+        internal const string GenAiAgentName = "gen_ai.agent.name";
+        internal const string GenAiAgentId = "gen_ai.agent.id";
+        internal const string GenAiAgentVersion = "gen_ai.agent.version";
+        internal const string GenAiConversationId = "gen_ai.conversation.id";
+
+        // Operation name
+        internal const string GenAiOperationName = "gen_ai.operation.name";
+        internal const string InvokeAgentOperationName = "invoke_agent";
+    }
+}

sdk/monitor/Azure.Monitor.OpenTelemetry.Exporter/src/Internals/GenAI/MainAgentAttributionLogProcessor.cs

@@ -0,0 +1,78 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+using System.Collections.Generic;
+using System.Diagnostics;
+using OpenTelemetry;
+using OpenTelemetry.Logs;
+
+using static Azure.Monitor.OpenTelemetry.Exporter.Internals.GenAI.MainAgentAttributeConstants;
+
+namespace Azure.Monitor.OpenTelemetry.Exporter.Internals.GenAI
+{
+    /// <summary>
+    /// A log processor that copies main-agent attributes from the current span
+    /// onto emitted log records so that logs are attributed to the user-facing agent.
+    /// </summary>
+    internal sealed class MainAgentAttributionLogProcessor : BaseProcessor<LogRecord>
+    {
+        private static readonly string[] s_mainAgentAttributes = new[]
+        {
+            MainAgentName,
+            MainAgentId,
+            MainAgentVersion,
+            MainAgentConversationId,
+        };
+
+        public override void OnEnd(LogRecord logRecord)
+        {
+            var activity = Activity.Current;
+            if (activity == null)
+            {
+                return;
+            }
+
+            // Quick check: skip if current span has no main agent attributes.
+            if (activity.GetTagItem(MainAgentName) == null &&
+                activity.GetTagItem(MainAgentId) == null)
+            {
+                return;
+            }
+
+            // Collect values into a stack-friendly fixed-size buffer to avoid
+            // unnecessary List allocations on every log record.
+            var values = new KeyValuePair<string, object?>[s_mainAgentAttributes.Length];
+            int count = 0;
+
+            foreach (var attributeKey in s_mainAgentAttributes)
+            {
+                var value = activity.GetTagItem(attributeKey);
+                if (value != null)
+                {
+                    values[count++] = new KeyValuePair<string, object?>(attributeKey, value);
+                }
+            }
+
+            if (count == 0)
+            {
+                return;
+            }
+
+            var existingAttributes = logRecord.Attributes;
+            var merged = new List<KeyValuePair<string, object?>>(
+                (existingAttributes?.Count ?? 0) + count);
+
+            if (existingAttributes != null)
+            {
+                merged.AddRange(existingAttributes);
+            }
+
+            for (int i = 0; i < count; i++)
+            {
+                merged.Add(values[i]);
+            }
+
+            logRecord.Attributes = merged;
+        }
+    }
+}