microsoft/graphrag · error · ValueError

AzureBlobStorage requires either a connection_string or acco

Error message

AzureBlobStorage requires either a connection_string or account_url to be specified.

What it means

AzureBlobStorage.__init__ requires exactly one auth credential. If both connection_string and account_url are None, the else branch logs and raises ValueError because the BlobServiceClient cannot be constructed anonymously.

Source

Thrown at packages/graphrag-storage/graphrag_storage/azure_blob_storage.py:68

        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:
            msg = "AzureBlobStorage requires either a connection_string or account_url to be specified."
            logger.error(msg)
            raise ValueError(msg)

        self._encoding = encoding
        self._container_name = container_name
        self._connection_string = connection_string
        self._base_dir = base_dir
        self._account_url = account_url
        self._storage_account_name = (
            account_url.split("//")[1].split(".")[0] if account_url else None
        )
        self._create_container()

    def _create_container(self) -> None:
        """Create the container if it does not exist."""
        if not self._container_exists():
            container_name = self._container_name
            container_names = [
                container.name
                for container in self._blob_service_client.list_containers()

View on GitHub (pinned to f40e9a26ce)

Solutions

1. Set the connection string env var or pass connection_string explicitly
2. Alternatively pass account_url and rely on DefaultAzureCredential (managed identity / az login)
3. Verify the settings loader actually maps the env var to the constructor argument
4. Check the variable isn't only defined in a different .env file or shell session

Example fix

# before
storage = AzureBlobStorage(container_name='mycontainer')  # no creds -> ValueError

# after
import os
storage = AzureBlobStorage(
    container_name='mycontainer',
    connection_string=os.environ['AZURE_STORAGE_CONNECTION_STRING'],
)

import os
conn = os.environ.get('AZURE_STORAGE_CONNECTION_STRING')
url = os.environ.get('AZURE_STORAGE_ACCOUNT_URL')
assert conn or url, "set AZURE_STORAGE_CONNECTION_STRING or AZURE_STORAGE_ACCOUNT_URL"

null

try:
    s = AzureBlobStorage(container_name=c)
except ValueError as e:
    if 'either a connection_string or account_url' in str(e):
        raise RuntimeError(f'missing storage credentials: {e}') from e
    raise

When it happens

Trigger: Instantiating AzureBlobStorage with neither connection_string nor account_url, typically because the relevant env vars are missing or were read under the wrong names.

Common situations: Missing AZURE_STORAGE_CONNECTION_STRING (or the graphrag-specific equivalent) in .env, running in a fresh environment/CI without secrets, or renaming settings fields so None is passed through.

Related errors

• AzureBlobStorage requires only one of connection_string or a
• 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/0c27efbd296036b0. Report an issue: GitHub.