# What This Sample Shows This sample demonstrates how to use background responses with ChatCompletionAgent and Azure OpenAI Responses for long-running operations. Background responses support: - **Polling for completion** - Non-streaming APIs can start a background operation and return a continuation token. Poll with the token until the response completes. - **Resuming after interruption** - Streaming APIs can be interrupted and resumed from the last update using the continuation token. > **Note:** Background responses are currently only supported by OpenAI Responses. For more information, see the [official documentation](https://learn.microsoft.com/en-us/agent-framework/user-guide/agents/agent-background-responses?pivots=programming-language-csharp). # Prerequisites Before you begin, ensure you have the following prerequisites: - .NET 10 SDK or later - Azure OpenAI service endpoint and deployment configured - Azure CLI installed and authenticated (for Azure credential authentication) **Note**: This demo uses Azure CLI credentials for authentication. Make sure you're logged in with `az login` and have access to the Azure OpenAI resource. For more information, see the [Azure CLI documentation](https://learn.microsoft.com/cli/azure/authenticate-azure-cli-interactively). Set the following environment variables: ```powershell $env:AZURE_OPENAI_ENDPOINT="https://your-resource.openai.azure.com/" # Replace with your Azure OpenAI resource endpoint $env:AZURE_OPENAI_DEPLOYMENT_NAME="gpt-4o-mini" # Optional, defaults to gpt-4o-mini ```