diff --git a/src/google/adk/cli/fast_api.py b/src/google/adk/cli/fast_api.py
index 8e87aec29e..ba4c784133 100644
--- a/src/google/adk/cli/fast_api.py
+++ b/src/google/adk/cli/fast_api.py
@@ -48,6 +48,7 @@
 from .utils.service_factory import create_artifact_service_from_options
 from .utils.service_factory import create_memory_service_from_options
 from .utils.service_factory import create_session_service_from_options
+from ..memory.base_memory_service import BaseMemoryService
 
 logger = logging.getLogger("google_adk." + __name__)
 
@@ -76,6 +77,7 @@ def get_fast_api_app(
     session_db_kwargs: Optional[Mapping[str, Any]] = None,
     artifact_service_uri: Optional[str] = None,
     memory_service_uri: Optional[str] = None,
+    memory_service: Optional[BaseMemoryService] = None,
     use_local_storage: bool = True,
     eval_storage_uri: Optional[str] = None,
     allow_origins: Optional[list[str]] = None,
@@ -110,13 +112,14 @@ def get_fast_api_app(
   load_services_module(agents_dir)
 
   # Build the Memory service
-  try:
-    memory_service = create_memory_service_from_options(
-        base_dir=agents_dir,
-        memory_service_uri=memory_service_uri,
-    )
-  except ValueError as exc:
-    raise click.ClickException(str(exc)) from exc
+  if memory_service is None:
+    try:
+      memory_service = create_memory_service_from_options(
+          base_dir=agents_dir,
+          memory_service_uri=memory_service_uri,
+      )
+    except ValueError as exc:
+      raise click.ClickException(str(exc)) from exc
 
   # Build the Session service
   session_service = create_session_service_from_options(