Back in stock announcement video for a sold-out product

For a back-in-stock announcement, make a 4 to 6 second vertical clip from the product's own photo, burn "Back in stock" and the availability facts onto it as cues, and attach it to whatever sends your restock message. Sume produces the clip; it does not collect waitlist sign-ups or send notifications. That belongs to your store platform or an email tool.

Shopify's Help Center, in its Flow workflow examples, lists a template named "Email waitlisted customers when a product is back in stock", so on Shopify the sending side is covered by Shopify's own tooling. The clip is the creative that goes inside that email or a social post.

Where the clip fits

The announcement has three jobs: say the item is back, say how many are available, and send people to the page. Only the first is video. For the general photo-to-clip route, see Product photo to video API. Keep stock counts out of the clip unless you will re-render when they change, because a burned-in "only 12 left" is stale the next hour.

• Photo: the same packshot used on the product page, hosted at a public HTTPS URL.
• Clip: Seedance image-to-video, first_frame, 9:16, 4 to 6 seconds.
• Text: cues like "BACK IN STOCK" and "Restocked today", burned by the caption job.
• Send: your own email, SMS or social tool, with the link.

Generate the clip

POST /v1/videos takes frame_images with frame_type first_frame; seedance-2.5 supports 4 to 30 seconds. Use an Idempotency-Key containing the SKU so a retry replays the same job instead of billing a second one. The price is reserved on submit at provider list times 1.25.

curl -X POST https://api.sume.com/v1/videos \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: back-in-stock-sku-4821" \
  -d '{
    "model": "seedance-2.5",
    "prompt": "Gentle turntable move around the product, soft studio light",
    "duration": 5,
    "aspect_ratio": "9:16",
    "frame_images": [{
      "type": "image_url",
      "image_url": {"url": "https://media.sume.com/artifacts/example/sku-4821.png"},
      "frame_type": "first_frame"
    }]
  }'

Add the words

Send the finished video URL to POST /v1/video-captions with cues (text, start, end). Authored cues skip speech-to-text and work on a silent clip; the job is $0.20 for videos up to 60 seconds (see the Video captions docs). If a restock is for twenty SKUs, run twenty jobs with twenty keys.

One honest limit: image-to-video animates the photo, it does not prove the stock exists. Only publish the clip after the inventory is actually available.