microsoft · westey-m · Apr 30, 2026 · Apr 30, 2026 · Apr 30, 2026 · Apr 30, 2026
diff --git a/dotnet/agent-framework-dotnet.slnx b/dotnet/agent-framework-dotnet.slnx
@@ -122,6 +122,7 @@
     <Project Path="samples/02-agents/Harness/Harness_Shared_Console/Harness_Shared_Console.csproj" />
     <Project Path="samples/02-agents/Harness/Harness_Step01_Research/Harness_Step01_Research.csproj" />
     <Project Path="samples/02-agents/Harness/Harness_Step02_Research_WithSubAgents/Harness_Step02_Research_WithSubAgents.csproj" />
+    <Project Path="samples/02-agents/Harness/Harness_Step03_DataProcessing/Harness_Step03_DataProcessing.csproj" />
   </Folder>
   <Folder Name="/Samples/02-agents/AGUI/Step05_StateManagement/">
     <Project Path="samples/02-agents/AGUI/Step05_StateManagement/Client/Client.csproj" />

diff --git a/...ples/02-agents/Harness/Harness_Step03_DataProcessing/Harness_Step03_DataProcessing.csproj b/...ples/02-agents/Harness/Harness_Step03_DataProcessing/Harness_Step03_DataProcessing.csproj
@@ -0,0 +1,24 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFrameworks>net10.0</TargetFrameworks>
+
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Azure.Identity" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\..\src\Microsoft.Agents.AI.OpenAI\Microsoft.Agents.AI.OpenAI.csproj" />
+    <ProjectReference Include="..\Harness_Shared_Console\Harness_Shared_Console.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Content Include="data\**\*" CopyToOutputDirectory="PreserveNewest" />
+  </ItemGroup>
+
+</Project>
diff --git a/dotnet/samples/02-agents/Harness/Harness_Step03_DataProcessing/Program.cs b/dotnet/samples/02-agents/Harness/Harness_Step03_DataProcessing/Program.cs
@@ -0,0 +1,110 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+// This sample demonstrates how to use a ChatClientAgent with the FileAccessProvider
+// to give an agent access to a folder of CSV data files. The agent can read, analyze,
+// and extract information from the data, then write results back as new files.
+//
+// The sample includes a pre-populated `data/` folder with sales transaction data.
+// Ask the agent to analyze the data, produce summaries, or create new output files.
+//
+// Special commands:
+//   exit — End the session.
+
+#pragma warning disable OPENAI001 // Suppress experimental API warnings for Responses API usage.
+#pragma warning disable MAAI001  // Suppress experimental API warnings for Agents AI experiments.
+
+using System.ClientModel.Primitives;
+using Azure.Identity;
+using Harness.Shared.Console;
+using Microsoft.Agents.AI;
+using Microsoft.Agents.AI.Compaction;
+using Microsoft.Extensions.AI;
+using OpenAI;
+using OpenAI.Responses;
+
+var endpoint = Environment.GetEnvironmentVariable("AZURE_FOUNDRY_OPENAI_ENDPOINT") ?? throw new InvalidOperationException("AZURE_FOUNDRY_OPENAI_ENDPOINT is not set.");
+var deploymentName = Environment.GetEnvironmentVariable("AZURE_AI_MODEL_DEPLOYMENT_NAME") ?? "gpt-5.4";
+
+const int MaxContextWindowTokens = 1_050_000;
+const int MaxOutputTokens = 128_000;
+
+// Point the file store at the data/ folder that ships with the sample.
+var dataFolder = Path.Combine(AppContext.BaseDirectory, "data");
+var fileStore = new FileSystemAgentFileStore(dataFolder);
+
+var instructions =
+    """
+    You are a data analyst assistant. You have access to a folder of data files via the FileAccess_* tools.
+
+    ## Getting started
+    - Start by listing available files with FileAccess_ListFiles to see what data is available.
+    - Read the files to understand their structure and contents.
+
+    ## Working with data
+    - When asked to analyze data, read the relevant files first, then perform the analysis.
+    - Show your analysis clearly with tables, summaries, and key insights.
+    - When calculations are needed, work through them step by step and show your reasoning.
+
+    ## Writing output
+    - When asked to produce output files (e.g., reports, summaries, filtered data), use FileAccess_SaveFile to write them.
+    - Use appropriate file formats: CSV for tabular data, Markdown for reports.
+    - Confirm what you wrote and where.
+
+    ## Important
+    - Never modify or delete the original input data files unless explicitly asked to do so.
+    - If asked about data you haven't read yet, read it first before answering.
+    - Always explain your reasoning and thought process as you work through tasks.
+    - Always explain what you learned and what you are going to do next between tool calls, so the user can follow along with your thought process.
+    """;
+
+// Create a compaction strategy based on the model's context window.
+var compactionStrategy = new ContextWindowCompactionStrategy(
+    maxContextWindowTokens: MaxContextWindowTokens,
+    maxOutputTokens: MaxOutputTokens);
+
+AIAgent agent =
+    new OpenAIClient(
+        new BearerTokenPolicy(new DefaultAzureCredential(), "https://ai.azure.com/.default"),
+        new OpenAIClientOptions()
+        {
+            Endpoint = new Uri(endpoint),
+            RetryPolicy = new ClientRetryPolicy(3)
+        })
+    .GetResponsesClient()
+    .AsIChatClientWithStoredOutputDisabled(deploymentName)
+
+    .AsBuilder()
+    .UseFunctionInvocation()
+    .UsePerServiceCallChatHistoryPersistence()
+    .UseAIContextProviders(new CompactionProvider(compactionStrategy))
+
+    .BuildAIAgent(
+        new ChatClientAgentOptions
+        {
+            Name = "DataAnalyst",
+            Description = "A data analyst assistant that reads, analyzes, and processes data files.",
+            UseProvidedChatClientAsIs = true,
+            RequirePerServiceCallChatHistoryPersistence = true,
+            ChatHistoryProvider = new InMemoryChatHistoryProvider(
+                new InMemoryChatHistoryProviderOptions
+                {
+                    ChatReducer = compactionStrategy.AsChatReducer(),
+                }),
+            AIContextProviders =
+            [
+                new FileAccessProvider(fileStore),
+            ],
+            ChatOptions = new ChatOptions
+            {
+                Instructions = instructions,
+                MaxOutputTokens = MaxOutputTokens,
+            },
+        })
+    .AsBuilder()
+    .Build();
+
+// Run the interactive console session.
+await HarnessConsole.RunAgentAsync(
+    agent,
+    title: "Data Processing Assistant",
+    userPrompt: "Ask me to analyze the data files, produce summaries, or create output files.");
diff --git a/dotnet/samples/02-agents/Harness/Harness_Step03_DataProcessing/README.md b/dotnet/samples/02-agents/Harness/Harness_Step03_DataProcessing/README.md
@@ -0,0 +1,65 @@
+# What this sample demonstrates
+
+This sample demonstrates how to use a `ChatClientAgent` with the `FileAccessProvider` to give an agent access to a folder of data files for reading, analyzing, and writing results.
+
+Key features showcased:
+
+- **FileAccessProvider** — gives the agent tools to read, write, list, search, and delete files in a shared data folder
+- **CSV data processing** — the agent reads sales transaction data and performs analysis on demand
+- **Output file creation** — the agent can write summaries, filtered data, or reports back to the data folder
+- **Streaming output** — responses are streamed token-by-token for a natural experience
+- **No planning mode** — this is a simple conversational sample focused on data interaction
+
+## Prerequisites
+
+Before running this sample, ensure you have:
+
+1. An Azure AI Foundry project with a deployed model (e.g., `gpt-5.4`)
+2. Azure CLI installed and authenticated (`az login`)
+
+## Environment Variables
+
+Set the following environment variables:
+
+```bash
+# Required: Your Azure AI Foundry OpenAI endpoint
+export AZURE_FOUNDRY_OPENAI_ENDPOINT="https://your-project.services.ai.azure.com/openai/v1/"
+
+# Optional: Model deployment name (defaults to gpt-5.4)
+export AZURE_AI_MODEL_DEPLOYMENT_NAME="gpt-5.4"
+```
+
+## Running the Sample
+
+```bash
+cd dotnet
+dotnet run --project samples/02-agents/Harness/Harness_Step03_DataProcessing
+```
+
+## What to Expect
+
+The sample starts an interactive conversation with a data analyst agent. The `data/` folder contains a `sales.csv` file with ~50 rows of sales transaction data (date, product, category, quantity, unit price, region, salesperson).
+
+You can ask the agent to:
+
+1. **List available files** — "What files do you have?"
+2. **Analyze the data** — "What are the total sales by region?" or "Which salesperson has the highest revenue?"
+3. **Create output files** — "Create a summary report as a markdown file" or "Write a CSV with monthly totals"
+4. **Search for patterns** — "Find all transactions over $1000"
+5. **Type `exit`** — to end the session
+
+E.g. try the following prompt `Please process the sales.csv file by first filtering it to only North region sales, and then calculating the sum of sales by person. I'd like to write the results of the processing to north_region_totals.csv`.
+
+## Sample Data
+
+The included `data/sales.csv` contains sales transactions from January to March 2025 with the following columns:
+
+| Column | Description |
+| --- | --- |
+| `date` | Transaction date (YYYY-MM-DD) |
+| `product` | Product name |
+| `category` | Product category (Electronics, Furniture, Stationery) |
+| `quantity` | Units sold |
+| `unit_price` | Price per unit |
+| `region` | Sales region (North, South, West) |
+| `salesperson` | Name of the salesperson |
diff --git a/dotnet/samples/02-agents/Harness/Harness_Step03_DataProcessing/data/sales.csv b/dotnet/samples/02-agents/Harness/Harness_Step03_DataProcessing/data/sales.csv
@@ -0,0 +1,50 @@
+date,product,category,quantity,unit_price,region,salesperson
+2025-01-03,Laptop Pro 15,Electronics,2,1299.99,North,Alice
+2025-01-05,Ergonomic Chair,Furniture,5,349.50,South,Bob
+2025-01-07,Wireless Mouse,Electronics,12,24.99,North,Alice
+2025-01-08,Standing Desk,Furniture,1,599.00,West,Carol
+2025-01-10,USB-C Hub,Electronics,8,45.99,North,David
+2025-01-12,Monitor 27in,Electronics,3,429.00,South,Bob
+2025-01-14,Desk Lamp,Furniture,6,79.95,West,Carol
+2025-01-15,Keyboard Mech,Electronics,4,149.99,North,Alice
+2025-01-17,Filing Cabinet,Furniture,2,189.00,South,David
+2025-01-20,Webcam HD,Electronics,10,89.99,West,Bob
+2025-01-22,Laptop Pro 15,Electronics,1,1299.99,South,Carol
+2025-01-24,Ergonomic Chair,Furniture,3,349.50,North,Alice
+2025-01-25,Notebook Pack,Stationery,20,12.99,South,David
+2025-01-27,Wireless Mouse,Electronics,15,24.99,West,Carol
+2025-01-28,Whiteboard,Stationery,4,129.00,North,Bob
+2025-01-30,Standing Desk,Furniture,2,599.00,South,Alice
+2025-02-02,USB-C Hub,Electronics,6,45.99,West,David
+2025-02-04,Monitor 27in,Electronics,2,429.00,North,Carol
+2025-02-05,Desk Lamp,Furniture,8,79.95,South,Bob
+2025-02-07,Keyboard Mech,Electronics,5,149.99,West,Alice
+2025-02-09,Filing Cabinet,Furniture,1,189.00,North,David
+2025-02-11,Webcam HD,Electronics,7,89.99,South,Carol
+2025-02-13,Laptop Pro 15,Electronics,3,1299.99,West,Bob
+2025-02-15,Notebook Pack,Stationery,30,12.99,North,Alice
+2025-02-17,Ergonomic Chair,Furniture,4,349.50,South,David
+2025-02-19,Wireless Mouse,Electronics,20,24.99,North,Carol
+2025-02-20,Whiteboard,Stationery,2,129.00,West,Bob
+2025-02-22,Standing Desk,Furniture,1,599.00,North,Alice
+2025-02-24,USB-C Hub,Electronics,10,45.99,South,David
+2025-02-26,Monitor 27in,Electronics,4,429.00,West,Carol
+2025-02-28,Desk Lamp,Furniture,3,79.95,North,Bob
+2025-03-02,Keyboard Mech,Electronics,6,149.99,South,Alice
+2025-03-04,Filing Cabinet,Furniture,3,189.00,West,David
+2025-03-06,Webcam HD,Electronics,9,89.99,North,Carol
+2025-03-08,Laptop Pro 15,Electronics,2,1299.99,South,Bob
+2025-03-10,Notebook Pack,Stationery,25,12.99,West,Alice
+2025-03-12,Ergonomic Chair,Furniture,6,349.50,North,David
+2025-03-14,Wireless Mouse,Electronics,18,24.99,South,Carol
+2025-03-15,Whiteboard,Stationery,5,129.00,North,Bob
+2025-03-17,Standing Desk,Furniture,3,599.00,West,Alice
+2025-03-19,USB-C Hub,Electronics,7,45.99,North,David
+2025-03-21,Monitor 27in,Electronics,5,429.00,South,Carol
+2025-03-23,Desk Lamp,Furniture,4,79.95,West,Bob
+2025-03-25,Keyboard Mech,Electronics,3,149.99,North,Alice
+2025-03-27,Filing Cabinet,Furniture,2,189.00,South,David
+2025-03-28,Webcam HD,Electronics,11,89.99,West,Carol
+2025-03-29,Laptop Pro 15,Electronics,1,1299.99,North,Bob
+2025-03-30,Notebook Pack,Stationery,15,12.99,South,Alice
+2025-03-31,Ergonomic Chair,Furniture,2,349.50,West,David
diff --git a/dotnet/samples/02-agents/Harness/README.md b/dotnet/samples/02-agents/Harness/README.md
@@ -8,3 +8,4 @@ Samples demonstrating the [Harness AIContextProviders](../../../src/Microsoft.Ag
 | --- | --- |
 | [Harness_Step01_Research](./Harness_Step01_Research/README.md) | Using a ChatClientAgent with TodoProvider and AgentModeProvider for research, showcasing planning mode and todo management |
 | [Harness_Step02_Research_WithSubAgents](./Harness_Step02_Research_WithSubAgents/README.md) | Using SubAgentsProvider to delegate stock price lookups to a web-search sub-agent concurrently |
+| [Harness_Step03_DataProcessing](./Harness_Step03_DataProcessing/README.md) | Using FileAccessProvider to give an agent access to CSV data files for reading, analysis, and output generation |