fix: Add custom_metadata to DatabaseSessionService

Resolve https://github.com/google/adk-python/issues/2677

PiperOrigin-RevId: 802375768

src/google/adk/sessions/database_session_service.py

@@ -231,21 +231,26 @@ class StorageEvent(Base):
 
   invocation_id: Mapped[str] = mapped_column(String(DEFAULT_MAX_VARCHAR_LENGTH))
   author: Mapped[str] = mapped_column(String(DEFAULT_MAX_VARCHAR_LENGTH))
+  actions: Mapped[MutableDict[str, Any]] = mapped_column(DynamicPickleType)
+  long_running_tool_ids_json: Mapped[Optional[str]] = mapped_column(
+      Text, nullable=True
+  )
   branch: Mapped[str] = mapped_column(
       String(DEFAULT_MAX_VARCHAR_LENGTH), nullable=True
   )
   timestamp: Mapped[PreciseTimestamp] = mapped_column(
       PreciseTimestamp, default=func.now()
   )
-  content: Mapped[dict[str, Any]] = mapped_column(DynamicJSON, nullable=True)
-  actions: Mapped[MutableDict[str, Any]] = mapped_column(DynamicPickleType)
 
-  long_running_tool_ids_json: Mapped[Optional[str]] = mapped_column(
-      Text, nullable=True
-  )
+  # === Fileds from llm_response.py ===
+  content: Mapped[dict[str, Any]] = mapped_column(DynamicJSON, nullable=True)
   grounding_metadata: Mapped[dict[str, Any]] = mapped_column(
       DynamicJSON, nullable=True
   )
+  custom_metadata: Mapped[dict[str, Any]] = mapped_column(
+      DynamicJSON, nullable=True
+  )
+
   partial: Mapped[bool] = mapped_column(Boolean, nullable=True)
   turn_complete: Mapped[bool] = mapped_column(Boolean, nullable=True)
   error_code: Mapped[str] = mapped_column(
@@ -309,6 +314,8 @@ class StorageEvent(Base):
       storage_event.grounding_metadata = event.grounding_metadata.model_dump(
           exclude_none=True, mode="json"
       )
+    if event.custom_metadata:
+      storage_event.custom_metadata = event.custom_metadata
     return storage_event
 
   def to_event(self) -> Event:
@@ -329,6 +336,7 @@ class StorageEvent(Base):
         grounding_metadata=_session_util.decode_grounding_metadata(
             self.grounding_metadata
         ),
+        custom_metadata=self.custom_metadata,
     )
 
 

tests/unittests/sessions/test_session_service.py

@@ -402,3 +402,42 @@ async def test_get_session_with_config(service_type):
   )
   events = session.events
   assert len(events) == num_test_events - after_timestamp + 1
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    'service_type', [SessionServiceType.IN_MEMORY, SessionServiceType.DATABASE]
+)
+async def test_append_event_with_fields(service_type):
+  session_service = get_session_service(service_type)
+  app_name = 'my_app'
+  user_id = 'test_user'
+  session = await session_service.create_session(
+      app_name=app_name, user_id=user_id, state={}
+  )
+
+  event = Event(
+      invocation_id='invocation',
+      author='user',
+      content=types.Content(role='user', parts=[types.Part(text='text')]),
+      long_running_tool_ids={'tool1', 'tool2'},
+      partial=False,
+      turn_complete=True,
+      error_code='ERROR_CODE',
+      error_message='error message',
+      interrupted=True,
+      grounding_metadata=types.GroundingMetadata(
+          web_search_queries=['query1'],
+      ),
+      custom_metadata={'custom_key': 'custom_value'},
+  )
+  await session_service.append_event(session, event)
+
+  retrieved_session = await session_service.get_session(
+      app_name=app_name, user_id=user_id, session_id=session.id
+  )
+  assert retrieved_session
+  assert len(retrieved_session.events) == 1
+  retrieved_event = retrieved_session.events[0]
+
+  assert retrieved_event == event