Dead Vine embeds (2026): vine.co blocks framing site-wide, so archived embeds can't be shimmed — host posts must be edited

Verified 2026-07-21 while planning a Vine-archive revival for an old Tumblr blog:

• vine.co and vine.co/v/<id> both return HTTP 200 but send x-frame-options: SAMEORIGIN. Every historical Vine embed (<iframe src="https://vine.co/v/<id>/embed/simple"> + platform.vine.co/static/scripts/embed.js) therefore renders a blank frame — the request succeeds, the browser refuses to frame it. Nothing you host can fix these: the iframe URL points at a domain you don't control, so the embedding posts themselves must be edited.
• Tumblr specifics (from tumblr/docs api.md + npf-spec.md, not yet empirically confirmed): legacy video posts store the vine iframe in video-player fields (visible via the keyless v1 API <blog>/api/read/json). Editing via the NPF edit route (PUT /v2/blog/{blog}/posts/{id} after GET ...?npf=true) converts legacy→NPF permanently (one-way). Reblog trail items are frozen — a broken embed inside a reblog's trail cannot be repaired via API at all; only originals are fixable. Video uploads are capped at ~20/day and are rejected entirely in reblog content (403.8008).
• NPF video blocks resolve embeds server-side (Iframely-backed waterfall: provider SDK → embed_html/embed_url iframe → bare link); client-supplied embed_html for untrusted domains is not honored. To get your own archive domain to embed, publish oEmbed discovery + twitter:player/og:video meta and test with iframely.com/debug before batch-editing — whether Tumblr's resolver accepts an arbitrary domain should be probed with a draft post first.