diff --git a/pyproject.toml b/pyproject.toml
index 23dbcb537..6cf78ab40 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -25,6 +25,7 @@ classifiers = [ # List of https://pypi.org/classifiers/
 ]
 dependencies = [
   # go/keep-sorted start
+  "PyYAML>=6.0.2",                                  # For APIHubToolset.
   "anyio>=4.9.0;python_version>='3.10'",            # For MCP Session Manager
   "authlib>=1.5.1",                                 # For RestAPI Tool
   "click>=8.1.8",                                   # For CLI tools
@@ -34,7 +35,7 @@ dependencies = [
   "google-cloud-secret-manager>=2.22.0",            # Fetching secrets in RestAPI Tool
   "google-cloud-speech>=2.30.0",                    # For Audio Transcription
   "google-cloud-storage>=2.18.0, <3.0.0",           # For GCS Artifact service
-  "google-genai>=1.17.0",                           # Google GenAI SDK
+  "google-genai>=1.21.1",                           # Google GenAI SDK
   "graphviz>=0.20.2",                               # Graphviz for graph rendering
   "mcp>=1.8.0;python_version>='3.10'",              # For MCP Toolset
   "opentelemetry-api>=1.31.0",                      # OpenTelemetry
@@ -43,7 +44,6 @@ dependencies = [
   "pydantic>=2.0, <3.0.0",                          # For data validation/models
   "python-dateutil>=2.9.0.post0",                   # For Vertext AI Session Service
   "python-dotenv>=1.0.0",                           # To manage environment variables
-  "PyYAML>=6.0.2",                                  # For APIHubToolset.
   "requests>=2.32.4",
   "sqlalchemy>=2.0",                                # SQL database ORM
   "starlette>=0.46.2",                              # For FastAPI CLI
@@ -70,9 +70,9 @@ dev = [
   # go/keep-sorted start
   "flit>=3.10.0",
   "isort>=6.0.0",
+  "mypy>=1.15.0",
   "pyink>=24.10.0",
   "pylint>=2.6.0",
-  "mypy>=1.15.0",
   # go/keep-sorted end
 ]
 
@@ -98,7 +98,6 @@ test = [
   "langgraph>=0.2.60",               # For LangGraphAgent
   "litellm>=1.71.2",                 # For LiteLLM tests
   "llama-index-readers-file>=0.4.0", # For retrieval tests
-
   "pytest-asyncio>=0.25.0",
   "pytest-mock>=3.14.0",
   "pytest-xdist>=3.6.1",
diff --git a/src/google/adk/models/google_llm.py b/src/google/adk/models/google_llm.py
index bff2b675c..ff91e7e29 100644
--- a/src/google/adk/models/google_llm.py
+++ b/src/google/adk/models/google_llm.py
@@ -183,7 +183,10 @@ def api_client(self) -> Client:
       The api client.
     """
     return Client(
-        http_options=types.HttpOptions(headers=self._tracking_headers)
+        http_options=types.HttpOptions(
+            headers=self._tracking_headers,
+            retry_options=types.HttpRetryOptions(),
+        ),  # Enable retries.
     )
 
   @cached_property