Deploy to Cloud Run using adk deploy cloud_run is not working

[v360-eduardo-marques]

I built a simple agent and I'm trying to deploy to Cloud Run using VertexAiSessionService. When I run adk deploy cloud_run its seems to work. But when I try to create a session using CURL I get a 500 - Internal Server Error

To Reproduce

Steps to reproduce the behavior:

1. Install adk pip install google-adk==1.15.1
2. Create simple agent

from google.adk.agents import Agent

system_instruction = (
    "Just say hi and be nice"
)

root_agent = Agent(
    name="my_test_agent",
    model='gemini-2.5-flash',
    instruction=system_instruction,
    description="Test agent",
)

3. Deploy the agent

adk deploy cloud_run \
    --project=<project_id> \
    --region=us-central1 \
    --service_name=my-agent \
    --app_name=my_agent \
    --session_service_uri='agentengine://<reasoning_engines_id ex:12342341234>' \
    --with_ui \
    my_agent

4. Try to create a session using curl

curl -X POST \
     $AGENT_URL/apps/my_agent/users/user_123/sessions/session_abc \
    -H "Content-Type: application/json" \
    -d '{"state": {"preferred_language": "English", "visit_count": 5}}'

5. Stacktrace of the error (Cloud Log

Traceback (most recent call last):
  File "/home/myuser/.local/lib/python3.11/site-packages/uvicorn/protocols/http/h11_impl.py", line 403, in run_asgi
    result = await app(  # type: ignore[func-returns-value]
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/myuser/.local/lib/python3.11/site-packages/uvicorn/middleware/proxy_headers.py", line 60, in __call__
    return await self.app(scope, receive, send)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/myuser/.local/lib/python3.11/site-packages/fastapi/applications.py", line 1133, in __call__
    await super().__call__(scope, receive, send)
  File "/home/myuser/.local/lib/python3.11/site-packages/starlette/applications.py", line 113, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/home/myuser/.local/lib/python3.11/site-packages/starlette/middleware/errors.py", line 186, in __call__
    raise exc
  File "/home/myuser/.local/lib/python3.11/site-packages/starlette/middleware/errors.py", line 164, in __call__
    await self.app(scope, receive, _send)
  File "/home/myuser/.local/lib/python3.11/site-packages/starlette/middleware/exceptions.py", line 63, in __call__
    await wrap_app_handling_exceptions(self.app, conn)(scope, receive, send)
  File "/home/myuser/.local/lib/python3.11/site-packages/starlette/_exception_handler.py", line 53, in wrapped_app
    raise exc
  File "/home/myuser/.local/lib/python3.11/site-packages/starlette/_exception_handler.py", line 42, in wrapped_app
    await app(scope, receive, sender)
  File "/home/myuser/.local/lib/python3.11/site-packages/fastapi/middleware/asyncexitstack.py", line 18, in __call__
    await self.app(scope, receive, send)
  File "/home/myuser/.local/lib/python3.11/site-packages/starlette/routing.py", line 716, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/home/myuser/.local/lib/python3.11/site-packages/starlette/routing.py", line 736, in app
    await route.handle(scope, receive, send)
  File "/home/myuser/.local/lib/python3.11/site-packages/starlette/routing.py", line 290, in handle
    await self.app(scope, receive, send)
  File "/home/myuser/.local/lib/python3.11/site-packages/fastapi/routing.py", line 123, in app
    await wrap_app_handling_exceptions(app, request)(scope, receive, send)
  File "/home/myuser/.local/lib/python3.11/site-packages/starlette/_exception_handler.py", line 53, in wrapped_app
    raise exc
  File "/home/myuser/.local/lib/python3.11/site-packages/starlette/_exception_handler.py", line 42, in wrapped_app
    await app(scope, receive, sender)
  File "/home/myuser/.local/lib/python3.11/site-packages/fastapi/routing.py", line 109, in app
    response = await f(request)
               ^^^^^^^^^^^^^^^^
  File "/home/myuser/.local/lib/python3.11/site-packages/fastapi/routing.py", line 387, in app
    raw_response = await run_endpoint_function(
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/myuser/.local/lib/python3.11/site-packages/fastapi/routing.py", line 288, in run_endpoint_function
    return await dependant.call(**values)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/myuser/.local/lib/python3.11/site-packages/google/adk/cli/adk_web_server.py", line 1252, in run_agent_sse
    session = await self.session_service.get_session(
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/myuser/.local/lib/python3.11/site-packages/google/adk/sessions/vertex_ai_session_service.py", line 195, in get_session
    get_session_api_response = await self._get_session_api_response(
                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/myuser/.local/lib/python3.11/site-packages/google/adk/sessions/vertex_ai_session_service.py", line 77, in _get_session_api_response
    get_session_api_response = await api_client.async_request(
                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/myuser/.local/lib/python3.11/site-packages/google/genai/_api_client.py", line 1325, in async_request
    result = await self._async_request(
             ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/myuser/.local/lib/python3.11/site-packages/google/genai/_api_client.py", line 1270, in _async_request
    return await self._async_retry(  # type: ignore[no-any-return]
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/myuser/.local/lib/python3.11/site-packages/tenacity/asyncio/__init__.py", line 111, in __call__
    do = await self.iter(retry_state=retry_state)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/myuser/.local/lib/python3.11/site-packages/tenacity/asyncio/__init__.py", line 153, in iter
    result = await action(retry_state)
             ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/myuser/.local/lib/python3.11/site-packages/tenacity/_utils.py", line 99, in inner
    return call(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/home/myuser/.local/lib/python3.11/site-packages/tenacity/__init__.py", line 418, in exc_check
    raise retry_exc.reraise()
          ^^^^^^^^^^^^^^^^^^^
  File "/home/myuser/.local/lib/python3.11/site-packages/tenacity/__init__.py", line 185, in reraise
    raise self.last_attempt.result()
          ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/concurrent/futures/_base.py", line 449, in result
    return self.__get_result()
           ^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/concurrent/futures/_base.py", line 401, in __get_result
    raise self._exception
  File "/home/myuser/.local/lib/python3.11/site-packages/tenacity/asyncio/__init__.py", line 114, in __call__
    result = await fn(*args, **kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/myuser/.local/lib/python3.11/site-packages/google/genai/_api_client.py", line 1250, in _async_request_once
    await errors.APIError.raise_for_async_response(client_response)
  File "/home/myuser/.local/lib/python3.11/site-packages/google/genai/errors.py", line 159, in raise_for_async_response
    raise ClientError(status_code, response_json, response)
google.genai.errors.ClientError: 404 NOT_FOUND. {'error': {'code': 404, 'message': 'Session (projectNumber: <project_number>, reasoningEngineId: <engine_id>, sessionId: 8859714613281816577) not found.', 'status': 'NOT_FOUND'}}

Desktop (please complete the following information):

• OS: macOS
• Python version(python -V): 3.11.9
• ADK version(pip show google-adk): 1.15.1

Screenshots
project structure

[DeanChensj]

Hi @v360-eduardo-marques , we have migrated vertex_ai_session_service to a new client SDK, does this issue still exist?

[devinhunsberger]

@DeanChensj is it necessary to implement the ADK runner while using the python client based vertexai/adk system for setting up agents. I have been having issues in regards to querying my agents despite using the client based system (without directly calling runner).

Agent Creation (I've left out most of the code as it's all within a large class)

#Returned as self.agent
app = AdkApp(
            agent = Agent(
                        model = "gemini-2.5-flash",
                        name = self.agent_name,
                        description = self.agent_description,
                        instruction = ...,
                        tools = self.agent_tools,
            ),
)
#...
remote_agent = CLIENT.agent_engines.create(
            agent = self.agent,
            config = dict(
                staging_bucket = self.staging_bucket,
                description = self.agent_description,
                display_name = self.agent_name,
                requirements = [
                    "google-cloud-aiplatform[agent_engines,rag]==1.120.0",
                    "google-adk==1.16.0",
                    "google-cloud-bigquery==3.34.0",
                    "timezonefinder==6.5.9",
                    "pytz==2025.2",
                    "requests",
                    "dotenv==0.9.9",
                    "pydantic==2.11.7",
                    "cloudpickle"],
                extra_packages = [...],
                env_vars = self.agent_env_vars
            )
        )

Attempting to query the agent

try:
            async for event in self.remote_agent.async_stream_query(
                user_id=self.userID,
                session_id=self.session_id,
                message=json.dumps(query),
            ):

Logs Output

2025-10-16 11:27:40.087
|   File "/HOME_PATH/lib/python3.12/site-packages/google/adk/runners.py", line 360, in _run_with_trace

2025-10-16 11:27:40.087
|     session = await self.session_service.get_session(

2025-10-16 11:27:40.087
|               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

2025-10-16 11:27:40.087
|   File "/HOME_PATH/lib/python3.12/site-packages/google/adk/sessions/vertex_ai_session_service.py", line 156, in get_session

2025-10-16 11:27:40.087
|     get_session_response = api_client.agent_engines.sessions.get(

2025-10-16 11:27:40.087
|                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

2025-10-16 11:27:40.087
|   File "/HOME_PATH/lib/python3.12/site-packages/vertexai/_genai/sessions.py", line 404, in get

2025-10-16 11:27:40.087
|     response = self._api_client.request("get", path, request_dict, http_options)

[... many lines of unredacted stack trace removed for brevity ...]

2025-10-16 11:27:40.088
|     raise ClientError(status_code, response_json, response)

2025-10-16 11:27:40.088
| google.genai.errors.ClientError: 404 NOT_FOUND. {'error': {'code': 404, 'message': 'The ReasoningEngine does not exist.', 'status': 'NOT_FOUND'}}

• OS: Docker python:3.12-slim-bookworm (Debian based)
• Python version(python -V): 3.12.3
• ADK version(pip show google-adk): 1.16.0

[DeanChensj]

Hi @v360-eduardo-marques, how did you set self.session_id? Did you get any error create that session?

[v360-eduardo-marques]

hi @DeanChensj . I chose a session_id randomly.

I noticed the problem is that I cannot create a session with a chosen session_id. Instead I have to create a session an then use the session_id provided.

The documentation is incomplete/outdated.

[DeanChensj]

Thanks, I think the issue is we didn't propagate the error from session service correctly to the adk web. Will send out a fix.