I asked a question yesterday about API access to setup EBSCO catalog sync, and that is moving forward now, as they will be using the public API. While working on that I also spent some time looking at the other API endpoints. I am able to use the authenticated APIs, but only if I login via our normal SAML SSO process first and then make the API calls on the authenticated session. I would like to eventually be able to use OAuth for some things here. However, I was not able to make OAuth work. Specifically, I am able to successfully request a token and set it with "Bearer " in the Authorization header, but no matter what I try I get 401 response with {"error":"Authentication failure."}. I've tried powershell and Postman from my own machine, and curl while logged into the koha server directly, but nothing I do seems to change anything. The user owning the API keys used with the request definitely has the needed permissions, and I even tried issuing an API key for a superlibrarian just to be sure. The RestPublicAPI and RESTOAuth2ClientCredentials system preferences are both enabled. What could I be missing? *Joel Coehoorn* Director of Information Technology *York University* Office: 402-363-5603 | jcoehoorn@york.edu | york.edu *Please contact helpdesk@york.edu <helpdesk@york.edu> for technical assistance.* The mission of York University is to transform lives through Christ-centered education and to equip students for lifelong service to God, family, and society