File search API not available with Vertex AI

[telolola]

Description of the bug:

The File Search API (file_search_stores) is marked as unavailable when using the Gemini client with Vertex AI authentication (vertexai=True).

This limitation blocks enterprise users who rely on Vertex AI service account authentication from using the File Search feature.

Actual vs expected behavior:

Tested using:

• SDK: google-genai version 1.50.1
• Python: 3.12
• Region: us-central1

Steps to reproduce:

from google import genai
from google.genai import types
import os

# Setup service account authentication
os.environ["GOOGLE_APPLICATION_CREDENTIALS"] = "/path/to/service-account.json"

# Initialize client with Vertex AI
client = genai.Client(
    vertexai=True,
    project="my-gcp-project",
    location="us-central1"
)

# Attempt to create File Search store
try:
    file_search_store = client.file_search_stores.create(
        config={'display_name': 'test-store'}
    )
except ValueError as e:
    print(e)
    # Output: "This method is only supported in the Gemini Developer client."

The file_search_stores.create(), upload_to_file_search_store(), and related File Search methods explicitly reject Vertex AI clients.

Any other information you'd like to share?

At a minimum, should cookbook state this limitation? The File Search documentation doesn't clearly indicate that this is a Gemini Developer API-only feature. The documentation shows how to initialize the client but doesn't mention the Vertex AI limitation.

e.g. prominent note at the top of the File Search docs:

⚠️ Note: File Search is currently only available with the Gemini Developer API (using API keys). It is not yet supported with Vertex AI authentication.

(unless I've missed this somewhere!)

[mikiastilahun]

@mrinalghoshh Is there any way we can help to make the fileSearchStore api be supported when using the VertexAi api?

Thanks

[shmishra99]

Hi @mikiastilahun,

The File Search API is currently available only via the Gemini API. I am creating a internal feature request for this issue. Thank you!

[markmcd]

if you want to use a RAG platform through Vertex AI and the GenAI SDK, you can use Vertex AI Search.

I realise they are not identical but check it out if you need a RAG tool.