https://github.com/docusign/docusign-esign-python-client/blob/330a500f29e91366766fb8def4947a28e4bcdff3/docusign_esign/client/api_client.py#L810 Correct me if I'm wrong, but this code will never execute. I would like to use this functionality :( It's not a blocker or any critical bug, because I can pass oauth_host_name to ApiClient constructor. Just letting you know this code looks strange.