Fix vector store create issue (#16804)

litellm/vector_stores/main.py

@@ -200,11 +200,15 @@ def create(
         if custom_llm_provider is None:
             custom_llm_provider = "openai"
 
-        api_type, custom_llm_provider, _, _ = get_llm_provider(
-            model=custom_llm_provider,
-            custom_llm_provider=None,
-            litellm_params=None,
-        )
+        if "/" in custom_llm_provider:
+            api_type, custom_llm_provider, _, _ = get_llm_provider(
+                model=custom_llm_provider,
+                custom_llm_provider=None,
+                litellm_params=None,
+            )
+        else:
+            api_type = None
+            custom_llm_provider = custom_llm_provider
 
         # get provider config - using vector store custom logger for now
         vector_store_provider_config = (

tests/test_litellm/vector_stores/test_vector_store_create_provider_logic.py

@@ -0,0 +1,102 @@
+import os
+import sys
+from unittest.mock import Mock, patch
+
+import pytest
+
+sys.path.insert(
+    0, os.path.abspath("../..")
+)  # Adds the parent directory to the system path
+
+import litellm
+from litellm.utils import ProviderConfigManager
+from litellm.llms.openai.vector_stores.transformation import OpenAIVectorStoreConfig
+from litellm.llms.vertex_ai.vector_stores.rag_api.transformation import VertexVectorStoreConfig
+
+
+def test_vector_store_create_with_simple_provider_name():
+    """
+    Test that vector store create correctly handles simple provider names
+    like "openai" (without "/" separator).
+    
+    This should:
+    - Set api_type to None
+    - Keep custom_llm_provider as "openai"
+    - Not call get_llm_provider (to avoid IndexError)
+    - Return correct OpenAIVectorStoreConfig
+    """
+    custom_llm_provider = "openai"
+    
+    # Simulate the logic from vector_stores/main.py create function
+    if "/" in custom_llm_provider:
+        # This branch should NOT be taken
+        pytest.fail("Should not enter this branch for simple provider name")
+    else:
+        api_type = None
+        custom_llm_provider = custom_llm_provider  # Keep as-is
+    
+    # Verify api_type is None
+    assert api_type is None, "api_type should be None for simple provider names"
+    
+    # Verify custom_llm_provider is unchanged
+    assert custom_llm_provider == "openai", "custom_llm_provider should remain 'openai'"
+    
+    # Verify ProviderConfigManager returns correct config
+    vector_store_provider_config = ProviderConfigManager.get_provider_vector_stores_config(
+        provider=litellm.LlmProviders(custom_llm_provider),
+        api_type=api_type,
+    )
+    
+    assert vector_store_provider_config is not None, "Should return a config for OpenAI"
+    assert isinstance(
+        vector_store_provider_config, OpenAIVectorStoreConfig
+    ), "Should return OpenAIVectorStoreConfig for OpenAI provider"
+    
+    print("✅ Test passed: Simple provider name 'openai' handled correctly")
+
+
+def test_vector_store_create_with_provider_api_type():
+    """
+    Test that vector store create correctly handles provider names with api_type
+    like "vertex_ai/rag_api" (with "/" separator).
+    
+    This should:
+    - Call get_llm_provider to extract api_type and provider
+    - Extract api_type as "rag_api"
+    - Extract custom_llm_provider as "vertex_ai"
+    - Return correct VertexVectorStoreConfig with api_type
+    """
+    from litellm.litellm_core_utils.get_llm_provider_logic import get_llm_provider
+    
+    custom_llm_provider = "vertex_ai/rag_api"
+    
+    # Simulate the logic from vector_stores/main.py create function
+    if "/" in custom_llm_provider:
+        api_type, custom_llm_provider, _, _ = get_llm_provider(
+            model=custom_llm_provider,
+            custom_llm_provider=None,
+            litellm_params=None,
+        )
+    else:
+        # This branch should NOT be taken
+        pytest.fail("Should not enter this branch for provider with api_type")
+    
+    # Verify api_type is extracted correctly
+    assert api_type == "rag_api", f"api_type should be 'rag_api', got '{api_type}'"
+    
+    # Verify custom_llm_provider is extracted correctly
+    assert custom_llm_provider == "vertex_ai", f"custom_llm_provider should be 'vertex_ai', got '{custom_llm_provider}'"
+    
+    # Verify ProviderConfigManager returns correct config
+    vector_store_provider_config = ProviderConfigManager.get_provider_vector_stores_config(
+        provider=litellm.LlmProviders(custom_llm_provider),
+        api_type=api_type,
+    )
+    
+    assert vector_store_provider_config is not None, "Should return a config for Vertex AI"
+    assert isinstance(
+        vector_store_provider_config, VertexVectorStoreConfig
+    ), "Should return VertexVectorStoreConfig for vertex_ai provider with rag_api"
+    
+    print("✅ Test passed: Provider with api_type 'vertex_ai/rag_api' handled correctly")
+