microsoft/semantic-kernel · error · ServiceInvalidRequestError

Collection name can not be empty.

Error message

Collection name can not be empty.

What it means

Raised by USearchMemoryStore.create_collection (ServiceInvalidRequestError, a ServiceResponseException subclass) when `collection_name.lower()` is an empty string. The store validates the name after lowercasing and before registering the collection, so an empty name is rejected up front rather than producing a corrupt in-memory entry.

Source

Thrown at python/semantic_kernel/connectors/memory_stores/usearch/usearch_memory_store.py:197

        Args:
            collection_name (str): Name of the collection. Case-insensitive.
                Must have name that is valid file name for the current OS environment.
            ndim (int, optional): Number of dimensions. Defaults to 0.
            metric (Union[str, MetricKind, CompiledMetric], optional): Metric kind. Defaults to MetricKind.IP.
            dtype (Optional[Union[str, ScalarKind]], optional): Data type. Defaults to None.
            connectivity (int, optional): Connectivity parameter. Defaults to None.
            expansion_add (int, optional): Expansion add parameter. Defaults to None.
            expansion_search (int, optional): Expansion search parameter. Defaults to None.
            view (bool, optional): Viewing flag. Defaults to False.

        Raises:
            ValueError: If collection with the given name already exists.
            ValueError: If collection name is empty string.
        """
        collection_name = collection_name.lower()
        if not collection_name:
            raise ServiceInvalidRequestError("Collection name can not be empty.")
        if collection_name in self._collections:
            raise ServiceInvalidRequestError(f"Collection with name {collection_name} already exists.")

        embeddings_index_path = (
            self._get_collection_path(collection_name, file_type=_CollectionFileType.USEARCH)
            if self._persist_directory
            else None
        )

        embeddings_index = Index(
            ndim=ndim,
            metric=metric,
            dtype=dtype,
            connectivity=connectivity,
            expansion_add=expansion_add,
            expansion_search=expansion_search,
            path=embeddings_index_path,
            view=view,

View on GitHub (pinned to c028a0c7dc)

Solutions

1. Provide a non-empty collection name: `await store.create_collection('my_docs')`.
2. Validate/strip the name before calling: `name = name.strip(); assert name`.
3. Fix the config or env source that yields an empty collection name.

Example fix

// before
await store.create_collection(cfg.get('collection', ''))
// after
name = (cfg.get('collection') or '').strip()
if not name:
    raise ValueError('collection name required')
await store.create_collection(name)

name = (collection_name or '').strip().lower()
if not name:
    raise ValueError('collection name must not be empty')
await store.create_collection(name)

def is_valid_collection_name(name: str | None) -> bool:
    return bool(name) and isinstance(name, str) and name.strip() != ''

from semantic_kernel.exceptions import ServiceInvalidRequestError
try:
    await store.create_collection(name)
except ServiceInvalidRequestError as e:
    if 'empty' in str(e):
        name = fallback_name
        await store.create_collection(name)
    else:
        raise

When it happens

Trigger: Calling `await store.create_collection('')` (or a variable that resolves to an empty string). Note: passing None fails earlier with AttributeError on `.lower()`, so this specifically guards empty strings.

Common situations: Collection name read from config/env that is unset and defaults to ''; whitespace-only names are NOT caught here (they pass the `not` check only if they strip to empty — they do not, since ' '.lower() is truthy); upstream code that builds names dynamically yielding ''.

Related errors

• Collection with name {collection_name} already exists.
• Limit must be less than or equal to {MAX_QUERY_WITHOUT_METAD
• Path of persist directory is not set
• Expected {expected_storage_files} files for collection {coll
• Collection {collection_name} does not exist, cannot insert.

AI-assisted analysis of microsoft/semantic-kernel@c028a0c7dc (2026-08-13). Data as JSON: /api/errors/4bb18316a0917688. Report an issue: GitHub.