TikTok comment poll, two endings: branch one last frame for $11.56

Two 10 second alternative endings from the same last frame cost $11.56 on Seedance 2.5 at 720p and 9:16, at $5.778 each. Pull the final frame with the video-frames endpoint, use it as the first frame of two different prompts, then let viewers pick in the comments. Metricool's TikTok news page reports comments now take polls of up to five options.

Only two options are made here, which keeps the cost bounded. Add a third ending only if the first two get a response.

The poll format as reported

The roundup lists, for comments, voice notes up to 60 seconds, polls with up to 5 options, photo carousels of 9 images and Live Photos. It also gives a figure of over 1.7 billion comments a day. It does not describe who can start a poll or whether creators can edit one. Check the TikTok app for that.

Cost of branching

Seedance 2.5 bills 720p at $0.5778 per second, so a 10 second ending is $5.778. Each branch is an independent generation. The frame extraction is billed by compute, with no fixed price, and is small next to the video jobs.

Get the last frame

Ask for a time just before the end. Every value in at must satisfy 0 <= t < duration, so for a 30 second episode, use 29.9. The request is always asynchronous; the submit returns 202 and you read the result later.

curl -X POST https://api.sume.com/v1/video-frames \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: poll-last-frame-ep4" \
  -d '{"video_url":"https://media.sume.com/artifacts/artf_ep4/ep4.mp4","at":[29.9]}'
# then GET /v1/video-frames/$REQUEST_ID and read frames[0].url once resource_status is ready

Generate both endings

Send two requests to POST /v1/videos with model seedance-2.5, duration 10, aspect_ratio 9:16, and a frame_images entry whose frame_type is first_frame and image_url.url is the frame. Use a different prompt and a different Idempotency-Key for each ending. Media inputs must live on media.sume.com, which the frame URL already does.

Ask viewers to vote in the comments, then publish the winner as the next episode or the pinned ending.

What Sume does not do

Sume does not create the poll or read votes. It also does not promise the new clip will match the old frame exactly; check the first second against the previous episode before posting.