feat(a2a): configurable request handler (#601)

Co-authored-by: jer <jerebill@amazon.com>

Author: jer96

src/strands/multiagent/a2a/server.py

@@ -10,8 +10,9 @@
 
 import uvicorn
 from a2a.server.apps import A2AFastAPIApplication, A2AStarletteApplication
+from a2a.server.events import QueueManager
 from a2a.server.request_handlers import DefaultRequestHandler
-from a2a.server.tasks import InMemoryTaskStore
+from a2a.server.tasks import InMemoryTaskStore, PushNotificationConfigStore, PushNotificationSender, TaskStore
 from a2a.types import AgentCapabilities, AgentCard, AgentSkill
 from fastapi import FastAPI
 from starlette.applications import Starlette
@@ -36,6 +37,12 @@ def __init__(
         serve_at_root: bool = False,
         version: str = "0.0.1",
         skills: list[AgentSkill] | None = None,
+        # RequestHandler
+        task_store: TaskStore | None = None,
+        queue_manager: QueueManager | None = None,
+        push_config_store: PushNotificationConfigStore | None = None,
+        push_sender: PushNotificationSender | None = None,
+
     ):
         """Initialize an A2A-compatible server from a Strands agent.
 
@@ -52,6 +59,14 @@ def __init__(
                 Defaults to False.
             version: The version of the agent. Defaults to "0.0.1".
             skills: The list of capabilities or functions the agent can perform.
+            task_store: Custom task store implementation for managing agent tasks. If None,
+                uses InMemoryTaskStore.
+            queue_manager: Custom queue manager for handling message queues. If None,
+                no queue management is used.
+            push_config_store: Custom store for push notification configurations. If None,
+                no push notification configuration is used.
+            push_sender: Custom push notification sender implementation. If None,
+                no push notifications are sent.
         """
         self.host = host
         self.port = port
@@ -77,7 +92,10 @@ def __init__(
         self.capabilities = AgentCapabilities(streaming=True)
         self.request_handler = DefaultRequestHandler(
             agent_executor=StrandsA2AExecutor(self.strands_agent),
-            task_store=InMemoryTaskStore(),
+            task_store=task_store or InMemoryTaskStore(),
+            queue_manager=queue_manager,
+            push_config_store=push_config_store,
+            push_sender=push_sender,
         )
         self._agent_skills = skills
         logger.info("Strands' integration with A2A is experimental. Be aware of frequent breaking changes.")