Feat: Firestore support

pyproject.toml

@@ -123,6 +123,7 @@ test = [
   "a2a-sdk>=0.3.0,<0.4.0",
   "anthropic>=0.43.0",                            # For anthropic model tests
   "crewai[tools];python_version>='3.11' and python_version<'3.12'",         # For CrewaiTool tests; chromadb/pypika fail on 3.12+
+  "google-cloud-firestore>=2.11.0",
   "kubernetes>=29.0.0",                           # For GkeCodeExecutor
   "langchain-community>=0.3.17",
   "langgraph>=0.2.60, <0.4.8",                    # For LangGraphAgent
@@ -157,6 +158,7 @@ extensions = [
   "beautifulsoup4>=3.2.2",                      # For load_web_page tool.
   "crewai[tools];python_version>='3.11' and python_version<'3.12'",       # For CrewaiTool; chromadb/pypika fail on 3.12+
   "docker>=7.0.0",                              # For ContainerCodeExecutor
+  "google-cloud-firestore>=2.11.0",             # For Firestore services
   "kubernetes>=29.0.0",                         # For GkeCodeExecutor
   "k8s-agent-sandbox>=0.1.1.post3",             # For GkeCodeExecutor sandbox mode
   "langgraph>=0.2.60, <0.4.8",                  # For LangGraphAgent

src/google/adk/errors/already_exists_error.py

@@ -18,7 +18,7 @@
 class AlreadyExistsError(Exception):
   """Represents an error that occurs when an entity already exists."""
 
-  def __init__(self, message="The resource already exists."):
+  def __init__(self, message: str = "The resource already exists."):
     """Initializes the AlreadyExistsError exception.
 
     Args:

src/google/adk/firestore_database_runner.py

@@ -0,0 +1,64 @@
+# Copyright 2026 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 os
+from typing import Optional
+from typing import TYPE_CHECKING
+
+from .artifacts.gcs_artifact_service import GcsArtifactService
+from .memory.firestore_memory_service import FirestoreMemoryService
+from .runners import Runner
+from .sessions.firestore_session_service import FirestoreSessionService
+
+if TYPE_CHECKING:
+  from .agents.base_agent import BaseAgent
+
+
+def create_firestore_runner(
+    agent: BaseAgent,
+    gcs_bucket_name: Optional[str] = None,
+    firestore_root_collection: Optional[str] = None,
+) -> Runner:
+  """Creates a Runner configured with Firestore and GCS services.
+
+  Args:
+    agent: The root agent to run.
+    gcs_bucket_name: The GCS bucket name for artifacts.
+    firestore_root_collection: The root collection name for Firestore.
+
+  Returns:
+    A Runner instance configured with Firestore services.
+  """
+  bucket_name = gcs_bucket_name or os.environ.get("ADK_GCS_BUCKET_NAME")
+  if not bucket_name:
+    raise ValueError(
+        "Required property 'ADK_GCS_BUCKET_NAME' is not set. This"
+        " is needed for the GcsArtifactService."
+    )
+  artifact_service = GcsArtifactService(bucket_name=bucket_name)
+
+  session_service = FirestoreSessionService(
+      root_collection=firestore_root_collection
+  )
+  memory_service = FirestoreMemoryService()
+
+  return Runner(
+      app_name=agent.name,
+      agent=agent,
+      session_service=session_service,
+      artifact_service=artifact_service,
+      memory_service=memory_service,
+  )