TikTok url_ownership_unverified with a media.sume.com URL

url_ownership_unverified is a 403 returned when you start a TikTok post with source=PULL_FROM_URL and the URL is not on a domain or URL prefix you verified in the TikTok for Developers portal. A media.sume.com URL is on Sume's host, not a domain you control, so you cannot verify it and should not expect it to pass. Either download the file and send it with FILE_UPLOAD, or copy it to a domain you control and verify that.

TikTok's rules are from its media transfer guide and Direct Post reference; Sume's facts from Video generation and Structured output, read 2026-10-01.

What does TikTok require for PULL_FROM_URL?

The guide says the media URL must belong to a path you own, confirmed by adding a Domain or URL Prefix property to your app in the portal; you need manage or write access. The URL must use https and should not redirect. Redirects are not followed, and a 3xx response is treated as invalid.

How does domain versus prefix verification differ?

Why can I not verify media.sume.com?

Sume serves generated files from media.sume.com, with a durable URL whose expires_at is null. That host is Sume's, so you cannot add its DNS record, and the URL is public by design: the docs note a durable URL is also a public URL. Sume's own tools run the other way too; Video Trim rejects a video_url that is not on the Sume media host with unsupported_media_source.

What are the two ways around it?

First, FILE_UPLOAD: poll the Sume job, download the video from the content URL, and send the bytes to the upload_url TikTok returns. Second, host a copy on your own verified domain and give TikTok that URL. Either way, keep your own copy rather than relying on a third party host. For chunking limits see TikTok chunk sizes.