Merge remote-tracking branch 'origin/main' into feat/hermes-phase1-provider-registry

workspace-template/main.py

@@ -12,7 +12,7 @@ import httpx
 import uvicorn
 from a2a.server.apps import A2AStarletteApplication
 from a2a.server.request_handlers import DefaultRequestHandler
-from a2a.server.tasks import InMemoryTaskStore, InMemoryPushNotificationConfigStore, PushNotificationSender
+from a2a.server.tasks import InMemoryTaskStore
 from a2a.types import AgentCard, AgentCapabilities, AgentSkill
 
 from adapters import get_adapter, AdapterConfig
@@ -152,12 +152,20 @@ async def main():  # pragma: no cover
         defaultOutputModes=["text/plain", "application/json"],
     )
 
-    # 7. Wrap in A2A
+    # 7. Wrap in A2A.
+    #
+    # Regression fix (#204): PR #198 tried to wire push_config_store +
+    # push_sender to satisfy #175 (push notification capability), but
+    # PushNotificationSender is an abstract base class in the a2a-sdk and
+    # can't be instantiated directly. Passing it crashed main.py on startup
+    # with `TypeError: Can't instantiate abstract class`. Dropped back to
+    # DefaultRequestHandler's own defaults — pushNotifications capability
+    # in the AgentCard below is still advertised via AgentCapabilities so
+    # clients know we COULD do pushes; actually implementing them requires
+    # a concrete sender subclass, tracked as a Phase-H follow-up to #175.
     handler = DefaultRequestHandler(
         agent_executor=executor,
         task_store=InMemoryTaskStore(),
-        push_config_store=InMemoryPushNotificationConfigStore(),
-        push_sender=PushNotificationSender(),
     )
 
     app = A2AStarletteApplication(