diff --git a/.env.example b/.env.example
index 8df496766..abea3f771 100644
--- a/.env.example
+++ b/.env.example
@@ -43,7 +43,7 @@ DOCKER_IMAGE_FRONTEND=frontend
 AWS_ACCESS_KEY_ID=
 AWS_SECRET_ACCESS_KEY=
 AWS_DEFAULT_REGION=ap-south-1
-AWS_S3_BUCKET_PREFIX = "bucket-prefix-name"
+AWS_S3_BUCKET_PREFIX="bucket-prefix-name"
 
 # OpenAI
 
diff --git a/backend/app/api/routes/collections.py b/backend/app/api/routes/collections.py
index 68e4b6a87..8682cb69f 100644
--- a/backend/app/api/routes/collections.py
+++ b/backend/app/api/routes/collections.py
@@ -1,26 +1,28 @@
 import inspect
 import logging
 import time
-import warnings
 from uuid import UUID, uuid4
 from typing import Any, List, Optional
 from dataclasses import dataclass, field, fields, asdict, replace
 
-from openai import OpenAI, OpenAIError
+from openai import OpenAIError, OpenAI
 from fastapi import APIRouter, HTTPException, BackgroundTasks, Query
 from fastapi import Path as FastPath
 from pydantic import BaseModel, Field, HttpUrl
-from sqlalchemy.exc import NoResultFound, MultipleResultsFound, SQLAlchemyError
+from sqlalchemy.exc import SQLAlchemyError
 
 from app.api.deps import CurrentUser, SessionDep, CurrentUserOrgProject
 from app.core.cloud import AmazonCloudStorage
-from app.core.config import settings
-from app.core.util import now, raise_from_unknown, post_callback
-from app.crud import DocumentCrud, CollectionCrud, DocumentCollectionCrud
+from app.core.util import now, post_callback
+from app.crud import (
+    DocumentCrud,
+    CollectionCrud,
+    DocumentCollectionCrud,
+)
 from app.crud.rag import OpenAIVectorStoreCrud, OpenAIAssistantCrud
 from app.models import Collection, Document
 from app.models.collection import CollectionStatus
-from app.utils import APIResponse, load_description
+from app.utils import APIResponse, load_description, get_openai_client
 
 logger = logging.getLogger(__name__)
 router = APIRouter(prefix="/collections", tags=["collections"])
@@ -180,12 +182,13 @@ def _backout(crud: OpenAIAssistantCrud, assistant_id: str):
 
 def do_create_collection(
     session: SessionDep,
-    current_user: CurrentUser,
+    current_user: CurrentUserOrgProject,
     request: CreationRequest,
     payload: ResponsePayload,
+    client: OpenAI,
 ):
     start_time = time.time()
-    client = OpenAI(api_key=settings.OPENAI_API_KEY)
+
     callback = (
         SilentCallback(payload)
         if request.callback_url is None
@@ -226,7 +229,7 @@ def do_create_collection(
         collection_crud._update(collection)
 
         elapsed = time.time() - start_time
-        logging.info(
+        logger.info(
             f"[do_create_collection] Collection created: {collection.id} | Time: {elapsed:.2f}s | "
             f"Files: {len(flat_docs)} | Sizes: {file_sizes_kb} KB | Types: {list(file_exts)}"
         )
@@ -261,6 +264,10 @@ def create_collection(
     request: CreationRequest,
     background_tasks: BackgroundTasks,
 ):
+    client = get_openai_client(
+        session, current_user.organization_id, current_user.project_id
+    )
+
     this = inspect.currentframe()
     route = router.url_path_for(this.f_code.co_name)
     payload = ResponsePayload("processing", route)
@@ -278,11 +285,7 @@ def create_collection(
 
     # 2. Launch background task
     background_tasks.add_task(
-        do_create_collection,
-        session,
-        current_user,
-        request,
-        payload,
+        do_create_collection, session, current_user, request, payload, client
     )
 
     logger.info(
@@ -294,9 +297,10 @@ def create_collection(
 
 def do_delete_collection(
     session: SessionDep,
-    current_user: CurrentUser,
+    current_user: CurrentUserOrgProject,
     request: DeletionRequest,
     payload: ResponsePayload,
+    client: OpenAI,
 ):
     if request.callback_url is None:
         callback = SilentCallback(payload)
@@ -306,7 +310,7 @@ def do_delete_collection(
     collection_crud = CollectionCrud(session, current_user.id)
     try:
         collection = collection_crud.read_one(request.collection_id)
-        assistant = OpenAIAssistantCrud()
+        assistant = OpenAIAssistantCrud(client)
         data = collection_crud.delete(collection, assistant)
         logger.info(
             f"[do_delete_collection] Collection deleted successfully | {{'collection_id': '{collection.id}'}}"
@@ -332,20 +336,20 @@ def do_delete_collection(
 )
 def delete_collection(
     session: SessionDep,
-    current_user: CurrentUser,
+    current_user: CurrentUserOrgProject,
     request: DeletionRequest,
     background_tasks: BackgroundTasks,
 ):
+    client = get_openai_client(
+        session, current_user.organization_id, current_user.project_id
+    )
+
     this = inspect.currentframe()
     route = router.url_path_for(this.f_code.co_name)
     payload = ResponsePayload("processing", route)
 
     background_tasks.add_task(
-        do_delete_collection,
-        session,
-        current_user,
-        request,
-        payload,
+        do_delete_collection, session, current_user, request, payload, client
     )
 
     logger.info(
diff --git a/backend/app/api/routes/documents.py b/backend/app/api/routes/documents.py
index 03d2cd98e..3924cabf5 100644
--- a/backend/app/api/routes/documents.py
+++ b/backend/app/api/routes/documents.py
@@ -8,8 +8,8 @@
 
 from app.crud import DocumentCrud, CollectionCrud
 from app.models import Document
-from app.utils import APIResponse, load_description
-from app.api.deps import CurrentUser, SessionDep
+from app.utils import APIResponse, load_description, get_openai_client
+from app.api.deps import CurrentUser, SessionDep, CurrentUserOrgProject
 from app.core.cloud import AmazonCloudStorage
 from app.crud.rag import OpenAIAssistantCrud
 
@@ -65,10 +65,14 @@ def upload_doc(
 )
 def remove_doc(
     session: SessionDep,
-    current_user: CurrentUser,
+    current_user: CurrentUserOrgProject,
     doc_id: UUID = FastPath(description="Document to delete"),
 ):
-    a_crud = OpenAIAssistantCrud()
+    client = get_openai_client(
+        session, current_user.organization_id, current_user.project_id
+    )
+
+    a_crud = OpenAIAssistantCrud(client)
     d_crud = DocumentCrud(session, current_user.id)
     c_crud = CollectionCrud(session, current_user.id)
 
@@ -84,10 +88,14 @@ def remove_doc(
 )
 def permanent_delete_doc(
     session: SessionDep,
-    current_user: CurrentUser,
+    current_user: CurrentUserOrgProject,
     doc_id: UUID = FastPath(description="Document to permanently delete"),
 ):
-    a_crud = OpenAIAssistantCrud()
+    client = get_openai_client(
+        session, current_user.organization_id, current_user.project_id
+    )
+
+    a_crud = OpenAIAssistantCrud(client)
     d_crud = DocumentCrud(session, current_user.id)
     c_crud = CollectionCrud(session, current_user.id)
     storage = AmazonCloudStorage(current_user)
diff --git a/backend/app/crud/rag/open_ai.py b/backend/app/crud/rag/open_ai.py
index 69479888f..cdb644abc 100644
--- a/backend/app/crud/rag/open_ai.py
+++ b/backend/app/crud/rag/open_ai.py
@@ -90,8 +90,12 @@ def clean(self, resource):
 
 
 class OpenAICrud:
-    def __init__(self, client=None):
-        self.client = client or OpenAI(api_key=settings.OPENAI_API_KEY)
+    def __init__(self, client):
+        if client is None:
+            logger.error("[OpenAICrud] OpenAI client is not configured")
+            raise ValueError("OpenAI client is not configured")
+
+        self.client = client
 
 
 class OpenAIVectorStoreCrud(OpenAICrud):
diff --git a/backend/app/tests/api/routes/collections/test_collection_info.py b/backend/app/tests/api/routes/collections/test_collection_info.py
index f28658866..5747f7905 100644
--- a/backend/app/tests/api/routes/collections/test_collection_info.py
+++ b/backend/app/tests/api/routes/collections/test_collection_info.py
@@ -4,12 +4,9 @@
 from sqlmodel import Session
 from app.core.config import settings
 from app.models import Collection
-from app.main import app
 from app.tests.utils.utils import get_user_from_api_key
 from app.models.collection import CollectionStatus
 
-client = TestClient(app)
-
 
 def create_collection(
     db,
diff --git a/backend/app/tests/api/routes/collections/test_create_collections.py b/backend/app/tests/api/routes/collections/test_create_collections.py
index ef779211e..2bede71aa 100644
--- a/backend/app/tests/api/routes/collections/test_create_collections.py
+++ b/backend/app/tests/api/routes/collections/test_create_collections.py
@@ -2,18 +2,16 @@
 from uuid import UUID
 import io
 
-import openai_responses
 from sqlmodel import Session
 from fastapi.testclient import TestClient
+from unittest.mock import patch
 
 from app.core.config import settings
 from app.tests.utils.document import DocumentStore
-from app.tests.utils.utils import openai_credentials, get_user_from_api_key
-from app.main import app
+from app.tests.utils.utils import get_user_from_api_key
 from app.crud.collection import CollectionCrud
 from app.models.collection import CollectionStatus
-
-client = TestClient(app)
+from app.tests.utils.openai import get_mock_openai_client_with_vector_store
 
 
 @pytest.fixture(autouse=True)
@@ -31,7 +29,7 @@ def stream(self, file_obj):
             return fake_file
 
         def get_file_size_kb(self, url: str) -> float:
-            return 1.0  # Simulate 1KB files
+            return 1.0
 
     class FakeS3Client:
         def head_object(self, Bucket, Key):
@@ -41,13 +39,16 @@ def head_object(self, Bucket, Key):
     monkeypatch.setattr("boto3.client", lambda service: FakeS3Client())
 
 
-@pytest.mark.usefixtures("openai_credentials")
 class TestCollectionRouteCreate:
     _n_documents = 5
 
-    @openai_responses.mock()
+    @patch("app.api.routes.collections.get_openai_client")
     def test_create_collection_success(
-        self, client: TestClient, db: Session, user_api_key_header
+        self,
+        mock_get_openai_client,
+        client: TestClient,
+        db: Session,
+        user_api_key_header,
     ):
         store = DocumentStore(db)
         documents = store.fill(self._n_documents)
@@ -60,8 +61,12 @@ def test_create_collection_success(
             "instructions": "Test collection assistant.",
             "temperature": 0.1,
         }
+
         headers = user_api_key_header
 
+        mock_openai_client = get_mock_openai_client_with_vector_store()
+        mock_get_openai_client.return_value = mock_openai_client
+
         response = client.post(
             f"{settings.API_V1_STR}/collections/create", json=body, headers=headers
         )
@@ -73,8 +78,8 @@ def test_create_collection_success(
         assert metadata["status"] == CollectionStatus.processing.value
         assert UUID(metadata["key"])
 
+        # Confirm collection metadata in DB
         collection_id = UUID(metadata["key"])
-
         user = get_user_from_api_key(db, headers)
         collection = CollectionCrud(db, user.user_id).read_one(collection_id)
 
diff --git a/backend/app/tests/api/routes/documents/test_route_document_info.py b/backend/app/tests/api/routes/documents/test_route_document_info.py
index 3f077935a..41b3ebc52 100644
--- a/backend/app/tests/api/routes/documents/test_route_document_info.py
+++ b/backend/app/tests/api/routes/documents/test_route_document_info.py
@@ -44,10 +44,7 @@ def test_info_reflects_database(
         assert source == target.data
 
     def test_cannot_info_unknown_document(
-        self,
-        db: Session,
-        route: Route,
-        crawler: Route,
+        self, db: Session, route: Route, crawler: Route
     ):
         DocumentStore.clear(db)
         maker = DocumentMaker(db)
diff --git a/backend/app/tests/api/routes/documents/test_route_document_permanent_remove.py b/backend/app/tests/api/routes/documents/test_route_document_permanent_remove.py
index 8a6d353fe..10d11f3ec 100644
--- a/backend/app/tests/api/routes/documents/test_route_document_permanent_remove.py
+++ b/backend/app/tests/api/routes/documents/test_route_document_permanent_remove.py
@@ -3,11 +3,14 @@
 from urllib.parse import urlparse
 
 import pytest
+from unittest.mock import patch
 from botocore.exceptions import ClientError
 from moto import mock_aws
 from sqlmodel import Session, select
 
+from openai import OpenAI
 import openai_responses
+from openai_responses import OpenAIMock
 
 from app.core.cloud import AmazonCloudStorageClient
 from app.core.config import settings
@@ -19,7 +22,6 @@
     WebCrawler,
     crawler,
 )
-from app.tests.utils.utils import openai_credentials
 
 
 @pytest.fixture
@@ -36,16 +38,23 @@ def aws_credentials():
     os.environ["AWS_DEFAULT_REGION"] = settings.AWS_DEFAULT_REGION
 
 
-@pytest.mark.usefixtures("openai_credentials", "aws_credentials")
+@pytest.mark.usefixtures("aws_credentials")
 @mock_aws
 class TestDocumentRoutePermanentRemove:
     @openai_responses.mock()
+    @patch("app.api.routes.documents.get_openai_client")
     def test_permanent_delete_document_from_s3(
         self,
+        mock_get_openai_client,
         db: Session,
         route: Route,
         crawler: WebCrawler,
     ):
+        openai_mock = OpenAIMock()
+        with openai_mock.router:
+            client = OpenAI(api_key="sk-test-key")
+            mock_get_openai_client.return_value = client
+
         # Setup AWS
         aws = AmazonCloudStorageClient()
         aws.create()
diff --git a/backend/app/tests/api/routes/documents/test_route_document_remove.py b/backend/app/tests/api/routes/documents/test_route_document_remove.py
index 7b01cc2f4..292b2b10a 100644
--- a/backend/app/tests/api/routes/documents/test_route_document_remove.py
+++ b/backend/app/tests/api/routes/documents/test_route_document_remove.py
@@ -1,6 +1,9 @@
 import pytest
 import openai_responses
+from openai_responses import OpenAIMock
+from openai import OpenAI
 from sqlmodel import Session, select
+from unittest.mock import patch
 
 from app.models import Document
 from app.tests.utils.document import (
@@ -10,8 +13,6 @@
     WebCrawler,
     crawler,
 )
-from app.tests.utils.collection import get_collection
-from app.tests.utils.utils import openai_credentials
 
 
 @pytest.fixture
@@ -19,47 +20,66 @@ def route():
     return Route("remove")
 
 
-@pytest.mark.usefixtures("openai_credentials")
 class TestDocumentRouteRemove:
     @openai_responses.mock()
+    @patch("app.api.routes.documents.get_openai_client")
     def test_response_is_success(
         self,
+        mock_get_openai_client,
         db: Session,
         route: Route,
         crawler: WebCrawler,
     ):
-        store = DocumentStore(db)
-        response = crawler.get(route.append(store.put()))
+        openai_mock = OpenAIMock()
+        with openai_mock.router:
+            client = OpenAI(api_key="sk-test-key")
+            mock_get_openai_client.return_value = client
 
-        assert response.is_success
+            store = DocumentStore(db)
+            response = crawler.get(route.append(store.put()))
+
+            assert response.is_success
 
     @openai_responses.mock()
+    @patch("app.api.routes.documents.get_openai_client")
     def test_item_is_soft_removed(
         self,
+        mock_get_openai_client,
         db: Session,
         route: Route,
         crawler: WebCrawler,
     ):
-        store = DocumentStore(db)
-        document = store.put()
+        openai_mock = OpenAIMock()
+        with openai_mock.router:
+            client = OpenAI(api_key="sk-test-key")
+            mock_get_openai_client.return_value = client
+
+            store = DocumentStore(db)
+            document = store.put()
 
-        crawler.get(route.append(document))
-        db.refresh(document)
-        statement = select(Document).where(Document.id == document.id)
-        result = db.exec(statement).one()
+            crawler.get(route.append(document))
+            db.refresh(document)
+            statement = select(Document).where(Document.id == document.id)
+            result = db.exec(statement).one()
 
-        assert result.deleted_at is not None
+            assert result.deleted_at is not None
 
     @openai_responses.mock()
+    @patch("app.api.routes.documents.get_openai_client")
     def test_cannot_remove_unknown_document(
         self,
+        mock_get_openai_client,
         db: Session,
         route: Route,
         crawler: WebCrawler,
     ):
-        DocumentStore.clear(db)
+        openai_mock = OpenAIMock()
+        with openai_mock.router:
+            client = OpenAI(api_key="sk-test-key")
+            mock_get_openai_client.return_value = client
 
-        maker = DocumentMaker(db)
-        response = crawler.get(route.append(next(maker)))
+            DocumentStore.clear(db)
+            maker = DocumentMaker(db)
+            response = crawler.get(route.append(next(maker)))
 
-        assert response.is_error
+            assert response.is_error
diff --git a/backend/app/tests/conftest.py b/backend/app/tests/conftest.py
index 46b74241a..027738714 100644
--- a/backend/app/tests/conftest.py
+++ b/backend/app/tests/conftest.py
@@ -1,11 +1,8 @@
-from collections.abc import Generator
-
 import pytest
-import time
-
 from fastapi.testclient import TestClient
 from sqlmodel import Session
 from sqlalchemy import event
+from collections.abc import Generator
 
 from app.core.config import settings
 from app.core.db import engine
diff --git a/backend/app/tests/crud/collections/test_crud_collection_create.py b/backend/app/tests/crud/collections/test_crud_collection_create.py
index 564230b33..d6feb064f 100644
--- a/backend/app/tests/crud/collections/test_crud_collection_create.py
+++ b/backend/app/tests/crud/collections/test_crud_collection_create.py
@@ -1,4 +1,3 @@
-import pytest
 import openai_responses
 from sqlmodel import Session, select
 
@@ -6,10 +5,8 @@
 from app.models import DocumentCollection
 from app.tests.utils.document import DocumentStore
 from app.tests.utils.collection import get_collection
-from app.tests.utils.utils import openai_credentials
 
 
-@pytest.mark.usefixtures("openai_credentials")
 class TestCollectionCreate:
     _n_documents = 10
 
diff --git a/backend/app/tests/crud/collections/test_crud_collection_delete.py b/backend/app/tests/crud/collections/test_crud_collection_delete.py
index 58d552d11..8029c5e80 100644
--- a/backend/app/tests/crud/collections/test_crud_collection_delete.py
+++ b/backend/app/tests/crud/collections/test_crud_collection_delete.py
@@ -8,16 +8,14 @@
 from app.crud.rag import OpenAIAssistantCrud
 from app.tests.utils.document import DocumentStore
 from app.tests.utils.collection import get_collection, uuid_increment
-from app.tests.utils.utils import openai_credentials
 
 
-@pytest.mark.usefixtures("openai_credentials")
 class TestCollectionDelete:
     _n_collections = 5
 
     @openai_responses.mock()
     def test_delete_marks_deleted(self, db: Session):
-        client = OpenAI(api_key=settings.OPENAI_API_KEY)
+        client = OpenAI(api_key="sk-test-key")
 
         assistant = OpenAIAssistantCrud(client)
         collection = get_collection(db, client)
@@ -29,7 +27,7 @@ def test_delete_marks_deleted(self, db: Session):
 
     @openai_responses.mock()
     def test_delete_follows_insert(self, db: Session):
-        client = OpenAI(api_key=settings.OPENAI_API_KEY)
+        client = OpenAI(api_key="sk-test-key")
 
         assistant = OpenAIAssistantCrud(client)
         collection = get_collection(db, client)
@@ -41,7 +39,7 @@ def test_delete_follows_insert(self, db: Session):
 
     @openai_responses.mock()
     def test_cannot_delete_others_collections(self, db: Session):
-        client = OpenAI(api_key=settings.OPENAI_API_KEY)
+        client = OpenAI(api_key="sk-test-key")
 
         assistant = OpenAIAssistantCrud(client)
         collection = get_collection(db, client)
@@ -56,7 +54,7 @@ def test_delete_document_deletes_collections(self, db: Session):
         store = DocumentStore(db)
         documents = store.fill(1)
 
-        client = OpenAI(api_key=settings.OPENAI_API_KEY)
+        client = OpenAI(api_key="sk-test-key")
         resources = []
         for _ in range(self._n_collections):
             coll = get_collection(db, client)
diff --git a/backend/app/tests/crud/collections/test_crud_collection_read_all.py b/backend/app/tests/crud/collections/test_crud_collection_read_all.py
index 39eb36e99..b6f63b884 100644
--- a/backend/app/tests/crud/collections/test_crud_collection_read_all.py
+++ b/backend/app/tests/crud/collections/test_crud_collection_read_all.py
@@ -4,11 +4,9 @@
 from sqlmodel import Session
 
 from app.crud import CollectionCrud
-from app.core.config import settings
 from app.models import Collection
 from app.tests.utils.document import DocumentStore
 from app.tests.utils.collection import get_collection
-from app.tests.utils.utils import openai_credentials
 
 
 def create_collections(db: Session, n: int):
@@ -18,7 +16,7 @@ def create_collections(db: Session, n: int):
 
     openai_mock = OpenAIMock()
     with openai_mock.router:
-        client = OpenAI(api_key=settings.OPENAI_API_KEY)
+        client = OpenAI(api_key="sk-test-key")
         for _ in range(n):
             collection = get_collection(db, client)
             if crud is None:
@@ -34,14 +32,10 @@ def refresh(self, db: Session):
     db.commit()
 
 
-@pytest.mark.usefixtures("openai_credentials")
 class TestCollectionReadAll:
     _ncollections = 5
 
-    def test_number_read_is_expected(
-        self,
-        db: Session,
-    ):
+    def test_number_read_is_expected(self, db: Session):
         db.query(Collection).delete()
 
         owner = create_collections(db, self._ncollections)
diff --git a/backend/app/tests/crud/collections/test_crud_collection_read_one.py b/backend/app/tests/crud/collections/test_crud_collection_read_one.py
index 22edba532..ed0d31ad4 100644
--- a/backend/app/tests/crud/collections/test_crud_collection_read_one.py
+++ b/backend/app/tests/crud/collections/test_crud_collection_read_one.py
@@ -8,7 +8,6 @@
 from app.crud import CollectionCrud
 from app.tests.utils.document import DocumentStore
 from app.tests.utils.collection import get_collection, uuid_increment
-from app.tests.utils.utils import openai_credentials
 
 
 def mk_collection(db: Session):
@@ -17,13 +16,12 @@ def mk_collection(db: Session):
 
     openai_mock = OpenAIMock()
     with openai_mock.router:
-        client = OpenAI(api_key=settings.OPENAI_API_KEY)
+        client = OpenAI(api_key="sk-test-key")
         collection = get_collection(db, client)
         crud = CollectionCrud(db, collection.owner_id)
         return crud.create(collection, documents)
 
 
-@pytest.mark.usefixtures("openai_credentials")
 class TestDatabaseReadOne:
     def test_can_select_valid_id(self, db: Session):
         collection = mk_collection(db)
@@ -35,7 +33,6 @@ def test_can_select_valid_id(self, db: Session):
 
     def test_cannot_select_others_collections(self, db: Session):
         collection = mk_collection(db)
-
         other = collection.owner_id + 1
         crud = CollectionCrud(db, other)
         with pytest.raises(NoResultFound):
diff --git a/backend/app/tests/crud/documents/test_crud_document_read_one.py b/backend/app/tests/crud/documents/test_crud_document_read_one.py
index 463ea02ea..a3de8f49d 100644
--- a/backend/app/tests/crud/documents/test_crud_document_read_one.py
+++ b/backend/app/tests/crud/documents/test_crud_document_read_one.py
@@ -33,11 +33,7 @@ def test_cannot_select_invalid_id(self, db: Session, store: DocumentStore):
         assert exc_info.value.status_code == 404
         assert "Document not found" in str(exc_info.value.detail)
 
-    def test_cannot_read_others_documents(
-        self,
-        db: Session,
-        store: DocumentStore,
-    ):
+    def test_cannot_read_others_documents(self, db: Session, store: DocumentStore):
         document = store.put()
         other = DocumentStore(db)
 
diff --git a/backend/app/tests/utils/collection.py b/backend/app/tests/utils/collection.py
index 0a68125c5..411af9947 100644
--- a/backend/app/tests/utils/collection.py
+++ b/backend/app/tests/utils/collection.py
@@ -36,7 +36,7 @@ def get_collection(db: Session, client=None):
     )
 
     if client is None:
-        client = OpenAI(api_key=settings.OPENAI_API_KEY)
+        client = OpenAI(api_key="test_api_key")
 
     vector_store = client.vector_stores.create()
     assistant = client.beta.assistants.create(
diff --git a/backend/app/tests/utils/openai.py b/backend/app/tests/utils/openai.py
index 778d4804f..6f11bbf51 100644
--- a/backend/app/tests/utils/openai.py
+++ b/backend/app/tests/utils/openai.py
@@ -1,6 +1,7 @@
 from typing import Optional
 import time
 
+from unittest.mock import MagicMock
 from openai.types.beta import Assistant as OpenAIAssistant
 from openai.types.beta.assistant import ToolResources, ToolResourcesFileSearch
 from openai.types.beta.assistant_tool import FileSearchTool
@@ -37,3 +38,33 @@ def mock_openai_assistant(
         top_p=1.0,
         reasoning_effort=None,
     )
+
+
+def get_mock_openai_client_with_vector_store():
+    mock_client = MagicMock()
+
+    # Vector store
+    mock_vector_store = MagicMock()
+    mock_vector_store.id = "mock_vector_store_id"
+    mock_client.vector_stores.create.return_value = mock_vector_store
+
+    # File upload + polling
+    mock_file_batch = MagicMock()
+    mock_file_batch.file_counts.completed = 2
+    mock_file_batch.file_counts.total = 2
+    mock_client.vector_stores.file_batches.upload_and_poll.return_value = (
+        mock_file_batch
+    )
+
+    # File list
+    mock_client.vector_stores.files.list.return_value = {"data": []}
+
+    # Assistant
+    mock_assistant = MagicMock()
+    mock_assistant.id = "mock_assistant_id"
+    mock_assistant.name = "Mock Assistant"
+    mock_assistant.model = "gpt-4o"
+    mock_assistant.instructions = "Mock instructions"
+    mock_client.beta.assistants.create.return_value = mock_assistant
+
+    return mock_client
diff --git a/backend/app/tests/utils/utils.py b/backend/app/tests/utils/utils.py
index d48ae5d33..ae4a7beef 100644
--- a/backend/app/tests/utils/utils.py
+++ b/backend/app/tests/utils/utils.py
@@ -3,6 +3,7 @@
 from uuid import UUID
 from typing import Type, TypeVar
 
+
 import pytest
 from pydantic import EmailStr
 from fastapi.testclient import TestClient
@@ -17,11 +18,6 @@
 T = TypeVar("T")
 
 
-@pytest.fixture(scope="class")
-def openai_credentials():
-    settings.OPENAI_API_KEY = "sk-fake123"
-
-
 def random_lower_string() -> str:
     return "".join(random.choices(string.ascii_lowercase, k=32))