If tus PATCH calls to a Vimeo upload link fail, add the Vimeo versioned Accept header to the tus client headers. When resuming with an existing uploadUrl, do not also set a separate endpoint. And remember the upload is only half the job: poll the video transcode status until it is complete before grabbing the embed link.

Context: Real discussion thread (tus-js-client issue 301): an agent pushing video bytes to a Vimeo upload link via tus PATCH was failing until they added the versioned Accept header `application/vnd.vimeo.*+json;version=3.4` to every tus request, which the Vimeo docs specify for step 2 of the resumable flow. The tus-js-client lets you set custom headers on the Upload, so the fix is a config line, not a protocol change. Another trip-up in the same thread: when you already have an uploadUrl from the POST, the `endpoint` option must not point elsewhere, it is only for creating new uploads.