Update custom_metadata per Issue 1292 - 8

docs/sessions/memory.md

@@ -585,6 +585,53 @@ For example, you can automate this step with a callback:
     --8<-- "examples/kotlin/snippets/sessions/MemoryExample.kt:auto_save_callback"
     ```
 
+## Extend memory capabilities
+
+Memory services extended from `BaseMemoryService` support adding sessions and
+events to agent memory, including custom metadata. Use the
+`add_session_to_memory` and `add_events_to_memory` methods of memory services
+such as `InMemoryMemoryService` to amend memory data, as shown in the
+following code example:
+
+```python
+import asyncio
+from google.adk.memory import InMemoryMemoryService
+
+# Assume my_memory_service is an instance of InMemoryMemoryService
+# and my_latest_events is a list of new adk.Event objects from the latest turn.
+my_latest_events = [...]
+
+async def update_incremental_memory(my_memory_service, my_latest_events):
+    # Example 1: Basic incremental update
+    await my_memory_service.add_events_to_memory(
+        app_name="my-app",
+        user_id="my-user",
+        events=my_latest_events,
+        session_id="my-optional-session-id"
+    )
+
+    # Example 2: Incremental update with Custom Metadata
+    await my_memory_service.add_events_to_memory(
+        app_name="my-app",
+        user_id="my-user",
+        events=my_latest_events,
+        session_id="my-optional-session-id",
+        custom_metadata={
+            "my_custom_key": "my_custom_value"
+        }
+    )
+
+async def update_session_memory(my_memory_service, my_completed_session):
+    # Example 3: Applying custom metadata to a full session
+    await my_memory_service.add_session_to_memory(
+        session=my_completed_session,
+        custom_metadata={
+            "category": "user_preference"
+        }
+    )
+
+```
+
 ## Advanced concepts
 
 ### How memory works in practice