feat: Add implementation of VertexAiMemoryBankService and support in FastAPI endpoint

PiperOrigin-RevId: 775327151

src/google/adk/cli/cli_tools_click.py

@@ -489,7 +489,8 @@ def adk_services_options():
         type=str,
         help=(
             """Optional. The URI of the memory service.
-            - Use 'rag://<rag_corpus_id>' to connect to Vertex AI Rag Memory Service."""
+            - Use 'rag://<rag_corpus_id>' to connect to Vertex AI Rag Memory Service.
+            - Use 'agentengine://<agent_engine_resource_id>' to connect to Vertex AI Memory Bank Service. e.g. agentengine://12345"""
         ),
         default=None,
     )

src/google/adk/cli/fast_api.py

@@ -71,6 +71,7 @@ from ..evaluation.local_eval_set_results_manager import LocalEvalSetResultsManag
 from ..evaluation.local_eval_sets_manager import LocalEvalSetsManager
 from ..events.event import Event
 from ..memory.in_memory_memory_service import InMemoryMemoryService
+from ..memory.vertex_ai_memory_bank_service import VertexAiMemoryBankService
 from ..memory.vertex_ai_rag_memory_service import VertexAiRagMemoryService
 from ..runners import Runner
 from ..sessions.database_session_service import DatabaseSessionService
@@ -282,6 +283,16 @@ def get_fast_api_app(
       memory_service = VertexAiRagMemoryService(
           rag_corpus=f'projects/{os.environ["GOOGLE_CLOUD_PROJECT"]}/locations/{os.environ["GOOGLE_CLOUD_LOCATION"]}/ragCorpora/{rag_corpus}'
       )
+    elif memory_service_uri.startswith("agentengine://"):
+      agent_engine_id = memory_service_uri.split("://")[1]
+      if not agent_engine_id:
+        raise click.ClickException("Agent engine id can not be empty.")
+      envs.load_dotenv_for_agent("", agents_dir)
+      memory_service = VertexAiMemoryBankService(
+          project=os.environ["GOOGLE_CLOUD_PROJECT"],
+          location=os.environ["GOOGLE_CLOUD_LOCATION"],
+          agent_engine_id=agent_engine_id,
+      )
     else:
       raise click.ClickException(
           "Unsupported memory service URI: %s" % memory_service_uri

src/google/adk/memory/__init__.py

@@ -15,12 +15,14 @@ import logging
 
 from .base_memory_service import BaseMemoryService
 from .in_memory_memory_service import InMemoryMemoryService
+from .vertex_ai_memory_bank_service import VertexAiMemoryBankService
 
 logger = logging.getLogger('google_adk.' + __name__)
 
 __all__ = [
     'BaseMemoryService',
     'InMemoryMemoryService',
+    'VertexAiMemoryBankService',
 ]
 
 try:
@@ -29,7 +31,7 @@ try:
   __all__.append('VertexAiRagMemoryService')
 except ImportError:
   logger.debug(
-      'The Vertex sdk is not installed. If you want to use the'
+      'The Vertex SDK is not installed. If you want to use the'
       ' VertexAiRagMemoryService please install it. If not, you can ignore this'
       ' warning.'
   )

src/google/adk/memory/vertex_ai_memory_bank_service.py

@@ -0,0 +1,147 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import annotations
+
+import json
+import logging
+from typing import Optional
+from typing import TYPE_CHECKING
+
+from typing_extensions import override
+
+from google import genai
+
+from .base_memory_service import BaseMemoryService
+from .base_memory_service import SearchMemoryResponse
+from .memory_entry import MemoryEntry
+
+if TYPE_CHECKING:
+  from ..sessions.session import Session
+
+logger = logging.getLogger('google_adk.' + __name__)
+
+
+class VertexAiMemoryBankService(BaseMemoryService):
+  """Implementation of the BaseMemoryService using Vertex AI Memory Bank."""
+
+  def __init__(
+      self,
+      project: Optional[str] = None,
+      location: Optional[str] = None,
+      agent_engine_id: Optional[str] = None,
+  ):
+    """Initializes a VertexAiMemoryBankService.
+
+    Args:
+      project: The project ID of the Memory Bank to use.
+      location: The location of the Memory Bank to use.
+      agent_engine_id: The ID of the agent engine to use for the Memory Bank.
+        e.g. '456' in
+        'projects/my-project/locations/us-central1/reasoningEngines/456'.
+    """
+    self._project = project
+    self._location = location
+    self._agent_engine_id = agent_engine_id
+
+  @override
+  async def add_session_to_memory(self, session: Session):
+    api_client = self._get_api_client()
+
+    if not self._agent_engine_id:
+      raise ValueError('Agent Engine ID is required for Memory Bank.')
+
+    events = []
+    for event in session.events:
+      if event.content and event.content.parts:
+        events.append({
+            'content': event.content.model_dump(exclude_none=True, mode='json')
+        })
+    request_dict = {
+        'direct_contents_source': {
+            'events': events,
+        },
+        'scope': {
+            'app_name': session.app_name,
+            'user_id': session.user_id,
+        },
+    }
+
+    api_response = await api_client.async_request(
+        http_method='POST',
+        path=f'reasoningEngines/{self._agent_engine_id}/memories:generate',
+        request_dict=request_dict,
+    )
+    logger.info(f'Generate memory response: {api_response}')
+
+  @override
+  async def search_memory(self, *, app_name: str, user_id: str, query: str):
+    api_client = self._get_api_client()
+
+    api_response = await api_client.async_request(
+        http_method='POST',
+        path=f'reasoningEngines/{self._agent_engine_id}/memories:retrieve',
+        request_dict={
+            'scope': {
+                'app_name': app_name,
+                'user_id': user_id,
+            },
+            'similarity_search_params': {
+                'search_query': query,
+            },
+        },
+    )
+    api_response = _convert_api_response(api_response)
+    logger.info(f'Search memory response: {api_response}')
+
+    if not api_response or not api_response.get('retrievedMemories', None):
+      return SearchMemoryResponse()
+
+    memory_events = []
+    for memory in api_response.get('retrievedMemories', []):
+      # TODO: add more complex error handling
+      memory_events.append(
+          MemoryEntry(
+              author='user',
+              content=genai.types.Content(
+                  parts=[
+                      genai.types.Part(text=memory.get('memory').get('fact'))
+                  ],
+                  role='user',
+              ),
+              timestamp=memory.get('updateTime'),
+          )
+      )
+    return SearchMemoryResponse(memories=memory_events)
+
+  def _get_api_client(self):
+    """Instantiates an API client for the given project and location.
+
+    It needs to be instantiated inside each request so that the event loop
+    management can be properly propagated.
+
+    Returns:
+      An API client for the given project and location.
+    """
+    client = genai.Client(
+        vertexai=True, project=self._project, location=self._location
+    )
+    return client._api_client
+
+
+def _convert_api_response(api_response):
+  """Converts the API response to a JSON object based on the type."""
+  if hasattr(api_response, 'body'):
+    return json.loads(api_response.body)
+  return api_response