Azure/azure-sdk-for-python azure-ai-agentserver-responses

1.0.0b4 (2026-04-19)

DELETE /responses/{id} no longer returns intermittent 404 when the background task's eager eviction races with the delete handler. Previously, try_evict could remove the record from in-memory state between the handler's get() and delete() calls, causing delete() to return False and producing a spurious 404. The handler now falls through to the durable provider when the in-memory delete fails due to a concurrent eviction.
POST /responses with background=true, stream=false now correctly returns status: "in_progress" instead of "completed". Handlers that yield events synchronously (no await between yields — the normal pattern with ResponseEventStream) would cause the background task to run to completion before run_background captured the initial snapshot. A cooperative yield after response_created_signal.set() now ensures the POST handler resumes promptly.
Conversation history IDs (previous_response_id, conversation_id) are now validated eagerly before the handler is invoked. A nonexistent reference now returns a 404 error to the client immediately, instead of being silently ignored or surfacing as an opaque error deep inside the handler. The prefetched IDs are reused by ResponseContext.get_history(), eliminating a redundant provider call.