Neat! cl = boto3.client( 's3', aws_access_key_id=access_key_id, aws_secret_access_key=secret_access_key, endpoint_url=endpoint,

Neat! cl = boto3.client( 's3', aws_access_key_id=access_key_id, aws_secret_access_key=secret_access_key, endpoint_url=endpoint, config=Config( region_name = endpoints[endpoint_name].get('region', 'auto'), s3={'addressing_style': 'path'}, retries=dict( max_attempts=0 ), ), ) dict "endpoints" is undefined in the example code above, replace that line with: region_name = 'auto', ---- While, an S3-compatible API, which exposes your bucket on a URL of the form bucket.account.r2storage.com. Should be? an S3-compatible API, which exposes your bucket on a URL of the form account.r2.cloudflarestorage.com/bucket