This sample demonstrates how to use the file search tool with AI agents. The file search tool allows agents to search through uploaded files stored in vector stores to answer user questions.

What this sample demonstrates

Uploading files and creating vector stores
Creating agents with file search capabilities
Using HostedFileSearchTool (MEAI abstraction)
Using native SDK file search tools (ResponseTool.CreateFileSearchTool)
Handling file citation annotations
Managing agent and resource lifecycle (creation and deletion)

Prerequisites

Before you begin, ensure you have the following prerequisites:

.NET 10 SDK or later
Azure Foundry service endpoint and deployment configured
Azure CLI installed and authenticated (for Azure credential authentication)

Note: This demo uses DefaultAzureCredential for authentication. For local development, make sure you're logged in with az login and have access to the Azure Foundry resource. For more information, see the Azure Identity documentation.

Set the following environment variables:

$env:AZURE_FOUNDRY_PROJECT_ENDPOINT="https://your-foundry-service.services.ai.azure.com/api/projects/your-foundry-project" # Replace with your Azure Foundry resource endpoint
$env:AZURE_FOUNDRY_PROJECT_DEPLOYMENT_NAME="gpt-4o-mini"  # Optional, defaults to gpt-4o-mini

Run the sample

Navigate to the FoundryAgents sample directory and run:

cd dotnet/samples/02-agents/FoundryAgents
dotnet run --project .\FoundryAgents_Step18_FileSearch

Expected behavior

The sample will:

Create a temporary text file with employee directory information
Upload the file to Azure Foundry
Create a vector store with the uploaded file
Create an agent with file search capabilities using one of:
- Option 1: Using HostedFileSearchTool (MEAI abstraction)
- Option 2: Using native SDK file search tools
Run a query against the agent to search through the uploaded file
Display file citation annotations from responses
Clean up resources (agent, vector store, and uploaded file)