agent-background-responses

Agent Background Responses

The Microsoft Agent Framework supports background responses for handling long-running operations that may take time to complete. This feature enables agents to start processing a request and return a continuation token that can be used to poll for results or resume interrupted streams.

[!TIP] For a complete working example, see the Background Responses sample.

When to Use Background Responses

Background responses are particularly useful for:

• Complex reasoning tasks that require significant processing time
• Operations that may be interrupted by network issues or client timeouts
• Scenarios where you want to start a long-running task and check back later for results
• Long-running tasks that also invoke function tools during background processing

How Background Responses Work

Background responses use a continuation token mechanism to handle long-running operations. When you send a request to an agent with background responses enabled, one of two things happens:

1. Immediate completion: The agent completes the task quickly and returns the final response without a continuation token
2. Background processing: The agent starts processing in the background and returns a continuation token instead of the final result

The continuation token contains all necessary information to either poll for completion using the non-streaming agent API or resume an interrupted stream with streaming agent API. When the continuation token is null, the operation is complete - this happens when a background response has completed, failed, or cannot proceed further (for example, when user input is required).

::: zone pivot="programming-language-csharp"

Enabling Background Responses

To enable background responses, set the AllowBackgroundResponses property to true in the AgentRunOptions:

AgentRunOptions options = new()
{
    AllowBackgroundResponses = true
};