beehiiv Content Import skips video posts: rebuild with Sume

beehiiv's Content Import tool does not import audio or video posts, so a Substack archive of those posts has to be recreated by hand. beehiiv's migration page names three ways to carry the content: the YouTube block, an HTML snippet embed for third-party players, and the native audio block. Sume can supply two of the pieces: a poster still from the video, and a detached audio file for the audio block.

beehiiv's side is from Ways to migrate audio and video posts from Substack to beehiiv, read 2026-10-03. Sume's is from Video frames and Audio detach.

What does beehiiv's page say?

That last point shapes the plan: video has to live elsewhere, and the post carries a link or an embed.

• The Content Import tool does not support importing audio or video posts; you recreate them.
• You can embed a video with the YouTube block.
• For third-party platforms such as Vimeo, paste the host's iframe code into an HTML snippet.
• The native audio block supports multiple file formats for self-hosted audio.
• iframe embeds will not display in email clients, so beehiiv suggests YouTube or Spotify embeds, or visibility settings that send email subscribers to the web version.
• beehiiv does not natively host video files in posts.

What can Sume rebuild for a video post?

Two things. First, a poster still, so the email has an image that stands in for the video. Video frames returns durable stills from a clip at source size, 1 to 24 per call. Second, the audio: audio detach turns the video's audio track into a wav (default) or mp3 at 128 kbps, for $0.01 a job, which fits the native audio block's self-hosted path.

Both need the source video on media.sume.com, so import it first with POST /v1/media-imports. The video itself still needs a home such as YouTube, as beehiiv's page says.

curl -X POST https://api.sume.com/v1/audio-detach \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: beehiiv-audio-001" \
  -d '{
    "video_url": "https://media.sume.com/artifacts/artf_demo/old-post.mp4",
    "format": "mp3",
    "channels": "mono"
  }'

What are the limits to plan around?

Audio detach accepts sources up to 1800 seconds, but output is capped at 900 seconds, so a longer track needs a range. A source with no audio track fails as detach_source_has_no_audio; check probe.has_audio first with video inspect. Video frames needs a time inside the clip, or the job fails as frame_time_out_of_range.

What does Sume not do for a migration?

Sume does not import posts, does not publish into beehiiv, and does not host a video player page. It makes the files you attach. Read each result's URL from GET /v1/jobs/:id/result (Jobs and results) and download or reference it in the beehiiv editor. Test how the post looks in an email preview before you send.