microsoft/graphrag · error · ValueError

AzureBlobStorage requires only one of connection_string or a

Error message

AzureBlobStorage requires only one of connection_string or account_url to be specified, not both.

What it means

AzureBlobStorage.__init__ accepts either connection_string (for key-based auth) or account_url (for token/DefaultAzureCredential auth). Supplying both makes the chosen auth path ambiguous, so the constructor logs and raises ValueError before creating the client.

Source

Thrown at packages/graphrag-storage/graphrag_storage/azure_blob_storage.py:47

    _encoding: str
    _account_url: str | None
    _blob_service_client: BlobServiceClient
    _storage_account_name: str | None

    def __init__(
        self,
        container_name: str,
        account_url: str | None = None,
        connection_string: str | None = None,
        base_dir: str | None = None,
        encoding: str = "utf-8",
        **kwargs: Any,
    ) -> None:
        """Create a new BlobStorage instance."""
        if connection_string is not None and account_url is not None:
            msg = "AzureBlobStorage requires only one of connection_string or account_url to be specified, not both."
            logger.error(msg)
            raise ValueError(msg)

        _validate_blob_container_name(container_name)

        logger.info(
            "Creating blob storage at [%s] and base_dir [%s]",
            container_name,
            base_dir,
        )
        if connection_string:
            self._blob_service_client = BlobServiceClient.from_connection_string(
                connection_string
            )
        elif account_url:
            self._blob_service_client = BlobServiceClient(
                account_url=account_url,
                credential=DefaultAzureCredential(),
            )
        else:

View on GitHub (pinned to f40e9a26ce)

Solutions

1. Remove or unset one of the two credentials (usually drop connection_string when moving to DefaultAzureCredential)
2. Audit .env / CI secrets for both variables being populated
3. Default the unused parameter to None explicitly at the call site

Example fix

# before
storage = AzureBlobStorage(
    container_name='mycontainer',
    connection_string=conn_str,
    account_url='https://mystorage.blob.core.windows.net',
)

# after
storage = AzureBlobStorage(
    container_name='mycontainer',
    account_url='https://mystorage.blob.core.windows.net',  # uses DefaultAzureCredential
)

assert not (connection_string and account_url), "pass only one of connection_string / account_url"
if account_url:
    connection_string = None

null

try:
    s = AzureBlobStorage(container_name=c, connection_string=cs, account_url=url)
except ValueError as e:
    if 'not both' in str(e):
        s = AzureBlobStorage(container_name=c, account_url=url)  # prefer managed identity
    else:
        raise

When it happens

Trigger: Instantiating AzureBlobStorage(container_name=..., connection_string=..., account_url=...) with both values non-None, often because settings loaders pass every non-empty env var through.

Common situations: A .env / settings object where both GRAPHRAG_STORAGE_CONNECTION_STRING and a storage account URL variable are set (e.g. leftover from switching from key auth to managed identity), or a generic kwargs-from-config constructor.

Related errors

• AzureBlobStorage requires either a connection_string or acco
• api_key should not be set when using Azure Managed Identity.
• Blob storage does yet not support listing keys.
• Container name must be between 3 and 63 characters long and
• No storage account blob url provided for blob storage.

AI-assisted analysis of microsoft/graphrag@f40e9a26ce (2026-08-27). Data as JSON: /api/errors/4f8b055f7ee35629. Report an issue: GitHub.