requests has not attribute session

[sakshamgoyal-01]

Determine this is the right repository

• I determined this is the correct repository in which to report this bug.

Summary of the issue

Faulty logic results in a bug. Here is a fix:

.venv/lib/python3.14/site-packages/google/auth/compute_engine/_metadata.py

    if use_mtls:
        # Ensure the request has a session to mount the adapter to.
-         if not request.session:
+        if not hasattr(request, "session") or not request.session:
            request.session = requests.Session()

API client name and version

google-genai==1.66.0

Reproduction steps: code

from google import genai
from google.genai import types

client = genai.Client(
    vertexai=True,
    project='...",
    location='global',
)
chat = client.chats.create(model='gemini-3-pro-preview')
response = chat.send_message("Hello. What is 2+2?")

Python environment

python 3.14

Python dependencies

[project]
name = "..."
version = "0.1.0"
readme = "README.md"
requires-python = ">=3.14"
dependencies = [
    "google-genai==1.66.0",
    "ipykernel>=7.2.0",
    "jupyter>=1.1.1",
]

Additional context

Error Log:

Details

File ~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/genai/chats.py:252, in Chat.send_message(self, message, config)
    247   raise ValueError(
    248       f"Message must be a valid part type: {types.PartUnion} or"
    249       f" {types.PartUnionDict}, got {type(message)}"
    250   )
    251 input_content = t.t_content(message)
--> [252](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/genai/chats.py:252) response = self._modules.generate_content(
    253     model=self._model,
    254     contents=self._curated_history + [input_content],  # type: ignore[arg-type]
    255     config=config if config else self._config,
    256 )
    257 model_output = (
    258     [response.candidates[0].content]
    259     if response.candidates and response.candidates[0].content
    260     else []
    261 )
    262 automatic_function_calling_history = (
    263     response.automatic_function_calling_history
    264     if response.automatic_function_calling_history
    265     else []
    266 )

File ~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/genai/models.py:[5644](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/genai/models.py:5644), in Models.generate_content(self, model, contents, config)
   5642 while remaining_remote_calls_afc > 0:
   5643   i += 1
-> 5644   response = self._generate_content(
   5645       model=model, contents=contents, config=parsed_config
   5646   )
   5648   function_map = _extra_utils.get_function_map(parsed_config)
   5649   if not function_map:

File ~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/genai/models.py:4306, in Models._generate_content(self, model, contents, config)
   4303 request_dict = _common.convert_to_dict(request_dict)
   4304 request_dict = _common.encode_unserializable_types(request_dict)
-> [4306](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/genai/models.py:4306) response = self._api_client.request(
   4307     'post', path, request_dict, http_options
   4308 )
   4310 if config is not None and getattr(
   4311     config, 'should_return_http_response', None
   4312 ):
   4313   return_value = types.GenerateContentResponse(sdk_http_response=response)

File ~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/genai/_api_client.py:1401, in BaseApiClient.request(self, http_method, path, request_dict, http_options)
   1391 def request(
   1392     self,
   1393     http_method: str,
   (...)   1396     http_options: Optional[HttpOptionsOrDict] = None,
   1397 ) -> SdkHttpResponse:
   1398   http_request = self._build_request(
   1399       http_method, path, request_dict, http_options
   1400   )
-> [1401](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/genai/_api_client.py:1401)   response = self._request(http_request, http_options, stream=False)
   1402   response_body = (
   1403       response.response_stream[0] if response.response_stream else ''
   1404   )
   1405   return SdkHttpResponse(headers=response.headers, body=response_body)

File ~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/genai/_api_client.py:1237, in BaseApiClient._request(self, http_request, http_options, stream)
   1234     retry = tenacity.Retrying(**retry_kwargs)
   1235     return retry(self._request_once, http_request, stream)  # type: ignore[no-any-return]
-> [1237](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/genai/_api_client.py:1237) return self._retry(self._request_once, http_request, stream)

File ~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/tenacity/__init__.py:470, in Retrying.__call__(self, fn, *args, **kwargs)
    468 retry_state = RetryCallState(retry_object=self, fn=fn, args=args, kwargs=kwargs)
    469 while True:
--> [470](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/tenacity/__init__.py:470)     do = self.iter(retry_state=retry_state)
    471     if isinstance(do, DoAttempt):
    472         try:

File ~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/tenacity/__init__.py:371, in BaseRetrying.iter(self, retry_state)
    369 result = None
    370 for action in self.iter_state.actions:
--> [371](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/tenacity/__init__.py:371)     result = action(retry_state)
    372 return result

File ~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/tenacity/__init__.py:413, in BaseRetrying._post_stop_check_actions.<locals>.exc_check(rs)
    411 retry_exc = self.retry_error_cls(fut)
    412 if self.reraise:
--> [413](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/tenacity/__init__.py:413)     raise retry_exc.reraise()
    414 raise retry_exc from fut.exception()

File ~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/tenacity/__init__.py:184, in RetryError.reraise(self)
    182 def reraise(self) -> t.NoReturn:
    183     if self.last_attempt.failed:
--> [184](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/tenacity/__init__.py:184)         raise self.last_attempt.result()
    185     raise self

File ~/.local/share/uv/python/cpython-3.14.3-linux-x86_64-gnu/lib/python3.14/concurrent/futures/_base.py:443, in Future.result(self, timeout)
    441     raise CancelledError()
    442 elif self._state == FINISHED:
--> [443](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/.local/share/uv/python/cpython-3.14.3-linux-x86_64-gnu/lib/python3.14/concurrent/futures/_base.py:443)     return self.__get_result()
    445 self._condition.wait(timeout)
    447 if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]:

File ~/.local/share/uv/python/cpython-3.14.3-linux-x86_64-gnu/lib/python3.14/concurrent/futures/_base.py:395, in Future.__get_result(self)
    393 if self._exception is not None:
    394     try:
--> [395](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/.local/share/uv/python/cpython-3.14.3-linux-x86_64-gnu/lib/python3.14/concurrent/futures/_base.py:395)         raise self._exception
    396     finally:
    397         # Break a reference cycle with the exception in self._exception
    398         self = None

File ~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/tenacity/__init__.py:473, in Retrying.__call__(self, fn, *args, **kwargs)
    471 if isinstance(do, DoAttempt):
    472     try:
--> [473](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/tenacity/__init__.py:473)         result = fn(*args, **kwargs)
    474     except BaseException:  # noqa: B902
    475         retry_state.set_exception(sys.exc_info())  # type: ignore[arg-type]

File ~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/genai/_api_client.py:1180, in BaseApiClient._request_once(self, http_request, stream)
   1178 # If using proj/location, fetch ADC
   1179 if self.vertexai and (self.project or self.location):
-> [1180](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/genai/_api_client.py:1180)   http_request.headers['Authorization'] = f'Bearer {self._access_token()}'
   1181   if self._credentials and self._credentials.quota_project_id:
   1182     http_request.headers['x-goog-user-project'] = (
   1183         self._credentials.quota_project_id
   1184     )

File ~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/genai/_api_client.py:1008, in BaseApiClient._access_token(self)
   1006 with self._sync_auth_lock:
   1007   if not self._credentials:
-> [1008](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/genai/_api_client.py:1008)     self._credentials, project = load_auth(project=self.project)
   1009     if not self.project:
   1010       self.project = project

File ~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/genai/_api_client.py:191, in load_auth(project)
    185 ## Set GOOGLE_API_PREVENT_AGENT_TOKEN_SHARING_FOR_GCP_SERVICES to false
    186 ## to disable bound token sharing. Tracking on
    187 ## https://github.com/googleapis/python-genai/issues/1956
    188 os.environ['GOOGLE_API_PREVENT_AGENT_TOKEN_SHARING_FOR_GCP_SERVICES'] = (
    189     'false'
    190 )
--> [191](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/genai/_api_client.py:191) credentials, loaded_project_id = google.auth.default(  # type: ignore[no-untyped-call]
    192     scopes=['https://www.googleapis.com/auth/cloud-platform'],
    193 )
    195 if not project:
    196   project = loaded_project_id

File ~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/auth/_default.py:718, in default(scopes, request, quota_project_id, default_scopes)
    706 checkers = (
    707     # Avoid passing scopes here to prevent passing scopes to user credentials.
    708     # with_scopes_if_required() below will ensure scopes/default scopes are
   (...)    714     lambda: _get_gce_credentials(request, quota_project_id=quota_project_id),
    715 )
    717 for checker in checkers:
--> [718](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/auth/_default.py:718)     credentials, project_id = checker()
    719     if credentials is not None:
    720         credentials = with_scopes_if_required(
    721             credentials, scopes, default_scopes=default_scopes
    722         )

File ~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/auth/_default.py:714, in default.<locals>.<lambda>()
    700 from google.auth.credentials import CredentialsWithQuotaProject
    702 explicit_project_id = os.environ.get(
    703     environment_vars.PROJECT, os.environ.get(environment_vars.LEGACY_PROJECT)
    704 )
    706 checkers = (
    707     # Avoid passing scopes here to prevent passing scopes to user credentials.
    708     # with_scopes_if_required() below will ensure scopes/default scopes are
    709     # safely set on the returned credentials since requires_scopes will
    710     # guard against setting scopes on user credentials.
    711     lambda: _get_explicit_environ_credentials(quota_project_id=quota_project_id),
    712     lambda: _get_gcloud_sdk_credentials(quota_project_id=quota_project_id),
    713     _get_gae_credentials,
--> [714](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/auth/_default.py:714)     lambda: _get_gce_credentials(request, quota_project_id=quota_project_id),
    715 )
    717 for checker in checkers:
    718     credentials, project_id = checker()

File ~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/auth/_default.py:410, in _get_gce_credentials(request, quota_project_id)
    407 if request is None:
    408     request = google.auth.transport._http_client.Request()
--> [410](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/auth/_default.py:410) if _metadata.is_on_gce(request=request):
    411     # Get the project ID.
    412     try:
    413         project_id = _metadata.get_project_id(request=request)

File ~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/auth/compute_engine/_metadata.py:135, in is_on_gce(request)
    132 if _NO_GCE_CHECK:
    133     return False
--> [135](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/auth/compute_engine/_metadata.py:135) if ping(request):
    136     return True
    138 if os.name == "nt":
    139     # TODO: implement GCE residency detection on Windows

File ~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/auth/compute_engine/_metadata.py:205, in ping(request, timeout, retry_count)
    192 """Checks to see if the metadata server is available.
    193 
    194 Args:
   (...)    202     bool: True if the metadata server is reachable, False otherwise.
    203 """
    204 use_mtls = _mtls.should_use_mds_mtls()
--> [205](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/auth/compute_engine/_metadata.py:205) _prepare_request_for_mds(request, use_mtls=use_mtls)
    206 # NOTE: The explicit ``timeout`` is a workaround. The underlying
    207 #       issue is that resolving an unknown host on some networks will take
    208 #       20-30 seconds; making this timeout short fixes the issue, but
    209 #       could lead to false negatives in the event that we are on GCE, but
    210 #       the metadata resolution was particularly slow. The latter case is
    211 #       "unlikely".
    212 headers = _METADATA_HEADERS.copy()

File ~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/auth/compute_engine/_metadata.py:180, in _prepare_request_for_mds(request, use_mtls)
    177 # Only modify the request if mTLS is enabled.
    178 if use_mtls:
    179     # Ensure the request has a session to mount the adapter to.
--> [180](https://vscode-remote+ssh-002dremote-002bgcp-002dwbi-002dsaksham-002dsdx-002dusc1-002d01.vscode-resource.vscode-cdn.net/home/ext_saksham_goyal_compassdigital/data-eng-des-projects/npc/~/data-eng-des-projects/npc/.venv/lib/python3.14/site-packages/google/auth/compute_engine/_metadata.py:180)     if not request.session:
    181         request.session = requests.Session()
    183     adapter = _mtls.MdsMtlsAdapter()

AttributeError: 'Request' object has no attribute 'session'

[Aramack]

I'm encountering the same error. This was a bug introduced in googleapis/google-auth-library-python@0387bb9.
It will default to checking if the /run/google-mds-mtls/root.crt exists. It appears that this was recently added to the google base images (I'm seeing it on the debian base image personally). It will then use MTLS for connections to the metadata server which triggers the buggy code path.

The three fixes I've found:

1. Set the environment variable GCE_METADATA_MTLS_MODE=none.
2. Rollback your google-auth package to 2.43.0 or earlier.
3. Set the compute engine metadata disable-https-mds-setup=true at the instance or project (https://docs.cloud.google.com/compute/docs/metadata/overview#https-mds-disabling-certificate-setup).

[sakshamgoyal-01]

@Aramack

The three fixes I've found:

Do I need to do all 3 of those?

[Aramack]

No you don't need all three. Any one should resolve it.

Set the environment variable GCE_METADATA_MTLS_MODE=none.

This disables the feature in python.

Rollback your google-auth package to 2.43.0 or earlier.

This removes the feature from your python environment. I would not receommend it as you'll stop getting other security fixes.

Set the compute engine metadata disable-https-mds-setup=true at the instance or project.

This tell compute engine not to create the /run/google-mds-mtls/root.crt certificate. So the feature returns to being disabled.

[daniel-sanche]

Thanks for reporting this, I'll make sure it gets into the next release