Thank you for the detailed response. This is just for me. I’ve tried using the Twitch-Api-Token header and persistant and api_token cookies to no avail. The server doesn’t seem to respond with a detailed message of why it’s failing, just a 500 Internal Server Error if it does not succeed. I got my values from the request headers sent in a GET info.json?on_site=1 request, and am sending them to https://clips.twitch.tv/clips via POST. Should I be doing this differently? And on a side note, have you been able to log in using the method you have suggested?