.NET: Add hosted agent observability sample

dotnet/agent-framework-dotnet.slnx

@@ -313,6 +313,9 @@
   <Folder Name="/Samples/04-hosting/FoundryHostedAgents/responses/Hosted-McpTools/">
     <Project Path="samples/04-hosting/FoundryHostedAgents/responses/Hosted-McpTools/HostedMcpTools.csproj" />
   </Folder>
+  <Folder Name="/Samples/04-hosting/FoundryHostedAgents/responses/Hosted-Observability/">
+    <Project Path="samples/04-hosting/FoundryHostedAgents/responses/Hosted-Observability/HostedObservability.csproj" />
+  </Folder>
   <Folder Name="/Samples/04-hosting/FoundryHostedAgents/responses/Hosted-Toolbox/">
     <Project Path="samples/04-hosting/FoundryHostedAgents/responses/Hosted-Toolbox/HostedToolbox.csproj" />
   </Folder>

dotnet/samples/04-hosting/FoundryHostedAgents/responses/Hosted-Observability/.env.example

@@ -0,0 +1,12 @@
+AZURE_AI_PROJECT_ENDPOINT=<your-azure-ai-project-endpoint>
+ASPNETCORE_URLS=http://+:8088
+ASPNETCORE_ENVIRONMENT=Development
+AZURE_AI_MODEL_DEPLOYMENT_NAME=gpt-4o
+AZURE_BEARER_TOKEN=DefaultAzureCredential
+
+# Capture prompt / completion / tool argument content on GenAI spans.
+OTEL_INSTRUMENTATION_GENAI_CAPTURE_MESSAGE_CONTENT=true
+
+# Uncomment and set to send local-run telemetry to Application Insights.
+# When the agent runs inside Foundry this value is injected automatically.
+#APPLICATIONINSIGHTS_CONNECTION_STRING=<your-app-insights-connection-string>

dotnet/samples/04-hosting/FoundryHostedAgents/responses/Hosted-Observability/Dockerfile

@@ -0,0 +1,17 @@
+# Use the official .NET 10.0 ASP.NET runtime as a parent image
+FROM mcr.microsoft.com/dotnet/aspnet:10.0 AS base
+WORKDIR /app
+
+FROM mcr.microsoft.com/dotnet/sdk:10.0 AS build
+WORKDIR /src
+COPY . .
+RUN dotnet restore
+RUN dotnet publish -c Release -o /app/publish
+
+# Final stage
+FROM base AS final
+WORKDIR /app
+COPY --from=build /app/publish .
+EXPOSE 8088
+ENV ASPNETCORE_URLS=http://+:8088
+ENTRYPOINT ["dotnet", "HostedObservability.dll"]

dotnet/samples/04-hosting/FoundryHostedAgents/responses/Hosted-Observability/Dockerfile.contributor

@@ -0,0 +1,19 @@
+# Dockerfile for contributors building from the agent-framework repository source.
+#
+# This project uses ProjectReference to the local Microsoft.Agents.AI.Foundry source,
+# which means a standard multi-stage Docker build cannot resolve dependencies outside
+# this folder. Instead, pre-publish the app targeting the container runtime and copy
+# the output into the container:
+#
+#   dotnet publish -c Debug -f net10.0 -r linux-musl-x64 --self-contained false -o out
+#   docker build -f Dockerfile.contributor -t hosted-observability .
+#   docker run --rm -p 8088:8088 -e AGENT_NAME=hosted-observability -e AZURE_BEARER_TOKEN=$AZURE_BEARER_TOKEN --env-file .env hosted-observability
+#
+# For end-users consuming the NuGet package (not ProjectReference), use the standard
+# Dockerfile which performs a full dotnet restore + publish inside the container.
+FROM mcr.microsoft.com/dotnet/aspnet:10.0-alpine AS final
+WORKDIR /app
+COPY out/ .
+EXPOSE 8088
+ENV ASPNETCORE_URLS=http://+:8088
+ENTRYPOINT ["dotnet", "HostedObservability.dll"]

dotnet/samples/04-hosting/FoundryHostedAgents/responses/Hosted-Observability/HostedObservability.csproj

@@ -0,0 +1,32 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFrameworks>net10.0</TargetFrameworks>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <CentralPackageTransitivePinningEnabled>false</CentralPackageTransitivePinningEnabled>
+    <RootNamespace>HostedObservability</RootNamespace>
+    <AssemblyName>HostedObservability</AssemblyName>
+    <NoWarn>$(NoWarn);</NoWarn>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Azure.AI.Projects" VersionOverride="2.1.0-beta.1" />
+    <PackageReference Include="Azure.Identity" />
+    <PackageReference Include="DotNetEnv" />
+  </ItemGroup>
+
+  <!-- For contributors: uses ProjectReference to build against local source -->
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\..\..\src\Microsoft.Agents.AI.Foundry\Microsoft.Agents.AI.Foundry.csproj" />
+    <ProjectReference Include="..\..\..\..\..\src\Microsoft.Agents.AI.Foundry.Hosting\Microsoft.Agents.AI.Foundry.Hosting.csproj" />
+  </ItemGroup>
+
+  <!-- For end-users: uncomment the PackageReference below and remove the ProjectReference above
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Agents.AI.Foundry" Version="1.0.0" />
+    <PackageReference Include="Microsoft.Agents.AI.Foundry.Hosting" Version="1.0.0" />
+  </ItemGroup>
+  -->
+
+</Project>

dotnet/samples/04-hosting/FoundryHostedAgents/responses/Hosted-Observability/Program.cs

@@ -0,0 +1,109 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+// Hosted Observability Agent - demonstrates that the Foundry hosting pipeline
+// emits OpenTelemetry traces, metrics and logs with no extra wiring required.
+// Two small tools are included so a request produces a span tree covering
+// agent invocation, the chat call, and tool execution.
+
+using System.ComponentModel;
+using Azure.AI.Projects;
+using Azure.Core;
+using Azure.Identity;
+using DotNetEnv;
+using Microsoft.Agents.AI;
+using Microsoft.Agents.AI.Foundry.Hosting;
+using Microsoft.Extensions.AI;
+
+// Load .env file if present (for local development)
+Env.TraversePath().Load();
+
+string endpoint = Environment.GetEnvironmentVariable("AZURE_AI_PROJECT_ENDPOINT")
+    ?? throw new InvalidOperationException("AZURE_AI_PROJECT_ENDPOINT is not set.");
+string deploymentName = Environment.GetEnvironmentVariable("AZURE_AI_MODEL_DEPLOYMENT_NAME") ?? "gpt-4o";
+
+// Use a chained credential: try a temporary dev token first (for local Docker debugging),
+// then fall back to DefaultAzureCredential (for local dev via dotnet run / managed identity in production).
+TokenCredential credential = new ChainedTokenCredential(
+    new DevTemporaryTokenCredential(),
+    new DefaultAzureCredential());
+
+// ── Tools ────────────────────────────────────────────────────────────────────
+
+string[] locations = ["New York", "London", "Paris", "Tokyo"];
+string[] conditions = ["sunny", "cloudy", "rainy", "stormy"];
+Random rng = new();
+
+[Description("Get the current location of the user.")]
+string GetCurrentLocation() => locations[rng.Next(locations.Length)];
+
+[Description("Get the weather for a given location.")]
+string GetWeather(
+    [Description("The location to get the weather for.")] string location)
+    => $"The weather in {location} is {conditions[rng.Next(conditions.Length)]} with a high of {rng.Next(10, 31)}°C.";
+
+// ── Create and host the agent ────────────────────────────────────────────────
+//
+// AddFoundryResponses automatically wraps `agent` with OpenTelemetryAgent
+// (see Microsoft.Agents.AI.Foundry.Hosting.ServiceCollectionExtensions.ApplyOpenTelemetry)
+// and the OTLP exporter is registered by Azure.AI.AgentServer.Core's
+// AddAgentHostTelemetry(). No additional observability wiring is required.
+
+AIAgent agent = new AIProjectClient(new Uri(endpoint), credential)
+    .AsAIAgent(
+        model: deploymentName,
+        instructions: "You are a friendly assistant. Keep your answers brief.",
+        name: Environment.GetEnvironmentVariable("AGENT_NAME") ?? "hosted-observability",
+        description: "A hosted agent that demonstrates Foundry observability.",
+        tools: [
+            AIFunctionFactory.Create(GetCurrentLocation),
+            AIFunctionFactory.Create(GetWeather),
+        ]);
+
+var builder = WebApplication.CreateBuilder(args);
+builder.Services.AddFoundryResponses(agent);
+
+var app = builder.Build();
+app.MapFoundryResponses();
+
+if (app.Environment.IsDevelopment())
+{
+    app.MapFoundryResponses("openai/v1");
+}
+
+app.Run();
+
+/// <summary>
+/// A <see cref="TokenCredential"/> for local Docker debugging only.
+/// Reads a pre-fetched bearer token from the <c>AZURE_BEARER_TOKEN</c> environment variable
+/// once at startup. This should NOT be used in production.
+///
+/// Generate a token on your host and pass it to the container:
+///   export AZURE_BEARER_TOKEN=$(az account get-access-token --resource https://ai.azure.com --query accessToken -o tsv)
+///   docker run -e AZURE_BEARER_TOKEN=$AZURE_BEARER_TOKEN ...
+/// </summary>
+internal sealed class DevTemporaryTokenCredential : TokenCredential
+{
+    private const string EnvironmentVariable = "AZURE_BEARER_TOKEN";
+    private readonly string? _token;
+
+    public DevTemporaryTokenCredential()
+    {
+        this._token = Environment.GetEnvironmentVariable(EnvironmentVariable);
+    }
+
+    public override AccessToken GetToken(TokenRequestContext requestContext, CancellationToken cancellationToken)
+        => this.GetAccessToken();
+
+    public override ValueTask<AccessToken> GetTokenAsync(TokenRequestContext requestContext, CancellationToken cancellationToken)
+        => new(this.GetAccessToken());
+
+    private AccessToken GetAccessToken()
+    {
+        if (string.IsNullOrEmpty(this._token) || this._token == "DefaultAzureCredential")
+        {
+            throw new CredentialUnavailableException($"{EnvironmentVariable} environment variable is not set.");
+        }
+
+        return new AccessToken(this._token, DateTimeOffset.UtcNow.AddHours(1));
+    }
+}

dotnet/samples/04-hosting/FoundryHostedAgents/responses/Hosted-Observability/README.md

@@ -0,0 +1,109 @@
+# Hosted-Observability
+
+A hosted [Agent Framework](https://github.com/microsoft/agent-framework) agent that demonstrates how the Foundry hosting pipeline emits OpenTelemetry traces, metrics and logs with no extra wiring.
+
+The agent has two small tools, `GetCurrentLocation` and `GetWeather`, so an end-to-end run produces a span tree covering agent invocation, the underlying chat call, and tool execution.
+
+## How it works
+
+### Instrumentation is on by default
+
+Unlike the Python SDK, the .NET hosting library is instrumented by default. `AddFoundryResponses(agent)` automatically wraps the agent with `OpenTelemetryAgent` (see `Microsoft.Agents.AI.Foundry.Hosting.ServiceCollectionExtensions.ApplyOpenTelemetry`) and the OTLP exporter pipeline is registered by `Azure.AI.AgentServer.Core`'s `AddAgentHostTelemetry()`. There is no `ENABLE_INSTRUMENTATION` flag to set.
+
+### Sensitive content
+
+Prompt, completion and tool argument content are omitted from spans by default. Set the OpenTelemetry standard environment variable to capture them:
+
+```env
+OTEL_INSTRUMENTATION_GENAI_CAPTURE_MESSAGE_CONTENT=true
+```
+
+This is the .NET equivalent of the Python sample's `ENABLE_SENSITIVE_DATA`. It is read by `OpenTelemetryAgent.EnableSensitiveData`.
+
+### Where the telemetry goes
+
+Foundry injects `APPLICATIONINSIGHTS_CONNECTION_STRING` when the agent runs in the hosted environment, so traces, metrics and logs flow to Application Insights with no code change. To send telemetry from a local run, set the connection string yourself in `.env`.
+
+## Prerequisites
+
+- [.NET 10 SDK](https://dotnet.microsoft.com/download/dotnet/10.0)
+- An Azure AI Foundry project with a deployed model (e.g., `gpt-4o`)
+- Azure CLI logged in (`az login`)
+
+## Configuration
+
+```bash
+cp .env.example .env
+```
+
+Edit `.env` and set your Azure AI Foundry project endpoint:
+
+```env
+AZURE_AI_PROJECT_ENDPOINT=https://<your-account>.services.ai.azure.com/api/projects/<your-project>
+ASPNETCORE_URLS=http://+:8088
+ASPNETCORE_ENVIRONMENT=Development
+AZURE_AI_MODEL_DEPLOYMENT_NAME=gpt-4o
+OTEL_INSTRUMENTATION_GENAI_CAPTURE_MESSAGE_CONTENT=true
+```
+
+> **Note:** `.env` is gitignored. The `.env.example` template is checked in as a reference.
+
+## Running directly (contributors)
+
+```bash
+cd dotnet/samples/04-hosting/FoundryHostedAgents/responses/Hosted-Observability
+AGENT_NAME=hosted-observability dotnet run
+```
+
+The agent starts on `http://localhost:8088`.
+
+### Test it
+
+```bash
+azd ai agent invoke --local "What is the current weather where I am?"
+```
+
+Or with curl:
+
+```bash
+curl -X POST http://localhost:8088/responses \
+  -H "Content-Type: application/json" \
+  -d '{"input": "What is the current weather where I am?", "model": "hosted-observability"}'
+```
+
+## Expected span tree
+
+A single request produces approximately the following spans:
+
+| Span | Source |
+|------|--------|
+| `invoke_agent` | Outer span emitted by the Azure AI AgentServer hosting SDK |
+| `agent_invoke <name>` | Emitted by `OpenTelemetryAgent` for each agent invocation |
+| `chat <model>` | Emitted by the underlying `IChatClient` for each model call |
+| `execute_tool <tool>` | Emitted for each invocation of `GetCurrentLocation` / `GetWeather` |
+
+See the [OpenTelemetry GenAI semantic conventions](https://opentelemetry.io/docs/specs/semconv/gen-ai/) for the attributes captured on each span.
+
+## Running with Docker
+
+This project uses `ProjectReference` to the local Agent Framework source, so use `Dockerfile.contributor` with a pre-published output:
+
+```bash
+dotnet publish -c Debug -f net10.0 -r linux-musl-x64 --self-contained false -o out
+docker build -f Dockerfile.contributor -t hosted-observability .
+
+export AZURE_BEARER_TOKEN=$(az account get-access-token --resource https://ai.azure.com --query accessToken -o tsv)
+docker run --rm -p 8088:8088 \
+  -e AGENT_NAME=hosted-observability \
+  -e AZURE_BEARER_TOKEN=$AZURE_BEARER_TOKEN \
+  --env-file .env \
+  hosted-observability
+```
+
+## Deploying to Foundry and viewing traces
+
+Once deployed, telemetry flows to the Application Insights instance attached to your Foundry project. In the Foundry UI, the **Traces** tab next to **Playground** lists conversations and lets you drill into the span tree for any request.
+
+## NuGet package users
+
+If consuming the Agent Framework as a NuGet package, use the standard `Dockerfile` instead of `Dockerfile.contributor`. See the commented section in `HostedObservability.csproj` for the `PackageReference` alternative.

dotnet/samples/04-hosting/FoundryHostedAgents/responses/Hosted-Observability/agent.manifest.yaml

@@ -0,0 +1,34 @@
+# yaml-language-server: $schema=https://raw.githubusercontent.com/microsoft/AgentSchema/refs/heads/main/schemas/v1.0/AgentManifest.yaml
+name: hosted-observability
+displayName: "Hosted Observability Agent"
+
+description: >
+  A hosted Agent Framework agent that demonstrates how the Foundry hosting
+  pipeline emits OpenTelemetry traces, metrics and logs to Application Insights
+  with no extra wiring required.
+
+metadata:
+  tags:
+    - AI Agent Hosting
+    - Azure AI AgentServer
+    - Responses Protocol
+    - Observability
+    - OpenTelemetry
+    - Agent Framework
+
+template:
+  name: hosted-observability
+  kind: hosted
+  protocols:
+    - protocol: responses
+      version: 1.0.0
+  resources:
+    cpu: "0.25"
+    memory: 0.5Gi
+  environment_variables:
+    # Capture prompt / completion / tool argument content on GenAI spans.
+    - name: OTEL_INSTRUMENTATION_GENAI_CAPTURE_MESSAGE_CONTENT
+      value: "true"
+parameters:
+  properties: []
+resources: []

dotnet/samples/04-hosting/FoundryHostedAgents/responses/Hosted-Observability/agent.yaml

@@ -0,0 +1,14 @@
+# yaml-language-server: $schema=https://raw.githubusercontent.com/microsoft/AgentSchema/refs/heads/main/schemas/v1.0/ContainerAgent.yaml
+kind: hosted
+name: hosted-observability
+protocols:
+  - protocol: responses
+    version: 1.0.0
+resources:
+  cpu: "0.25"
+  memory: 0.5Gi
+environment_variables:
+  # Capture prompt / completion / tool argument content on GenAI spans.
+  # See https://opentelemetry.io/docs/specs/semconv/gen-ai/ for the standard env var.
+  - name: OTEL_INSTRUMENTATION_GENAI_CAPTURE_MESSAGE_CONTENT
+    value: "true"