BerriAI/litellm · error · HTTPException

Collection {collection_name} is not a litellm managed vector

Error message

Collection {collection_name} is not a litellm managed vector store index. Only litellm managed vector store indexes are supported.

What it means

The 'collectionName' supplied to the Milvus /vectors pass-through was found in neither the vector store index registry nor the vector store registry, i.e. it does not correspond to a LiteLLM-managed vector store index. Only managed indexes can be proxied through this endpoint because credentials and routing must be resolved server-side.

Source

Thrown at litellm/proxy/pass_through_endpoints/llm_passthrough_endpoints.py:475

    if not collection_name:
        raise HTTPException(
            status_code=400,
            detail=f"Collection name is required. Got {request_body}",
        )

    if not litellm.vector_store_index_registry or not litellm.vector_store_registry:
        raise HTTPException(
            status_code=500,
            detail="Unable to find Milvus vector store index registry or vector store registry.",
        )

    # check if vector store index
    is_vector_store_index: Final = litellm.vector_store_index_registry.is_vector_store_index(
        vector_store_index_name=collection_name
    )

    if not is_vector_store_index:
        raise HTTPException(
            status_code=400,
            detail=f"Collection {collection_name} is not a litellm managed vector store index. Only litellm managed vector store indexes are supported.",
        )

    is_allowed_to_call_vector_store_endpoint(
        index_name=collection_name,
        provider=LlmProviders.MILVUS,
        request=request,
        user_api_key_dict=user_api_key_dict,
    )
    # get the vector store name from index registry

    index_object: Final = (
        (litellm.vector_store_index_registry.get_vector_store_index_by_name(vector_store_index_name=collection_name))
        if litellm.vector_store_index_registry is not None
        else None
    )
    if index_object is None:

View on GitHub (pinned to 77b7c6c40c)

Solutions

1. Use a collection that was created as a litellm managed vector store index; unmanaged Milvus collections are not supported on this route.
2. Create the index via the litellm vector store management API, then retry with that collection name.

When it happens

Trigger: Thrown at litellm/proxy/pass_through_endpoints/llm_passthrough_endpoints.py:475 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of BerriAI/litellm@77b7c6c40c (2026-08-18). Data as JSON: /api/errors/302f22263ca56495. Report an issue: GitHub.