Symphony Seedance 2.5 is invite-only: the API route today

TikTok Symphony with Dreamina Seedance 2.5, dated August 3, 2026, is offered only to select paid advertisers in select markets. If you are not one of them, the Sume API accepts seedance-2.5 for 4 to 30 seconds at 480p, 720p or 1080p through POST /v1/videos.

What TikTok announced

The figures below come from the TikTok for Business post, read on 2026-10-03. Check availability for your account and market there.

What Sume documents for the same model family

Limits on Sume are per model. seedance-2.5 accepts 4 to 30 seconds at 480p, 720p and 1080p; seedance-2 tops out at 15 seconds. Audio and video references are honored by the Seedance 2.x models. The reference counts above are TikTok's and Sume does not claim the same: the legacy Video 1.0 docs list 1 to 9 image, 1 to 3 video and 1 to 3 audio references, with audio requiring at least one image or video reference. Read supported_input_references from GET /v1/videos/models for a model's real inputs.

Sume does not describe a watermark or label on its outputs in these docs. If your channel requires disclosure, add it yourself.

Submit a clip

Use Idempotency-Key so a retry returns the original job. Poll the returned polling_url until the status is completed, then download from unsigned_urls.

curl -X POST https://api.sume.com/v1/videos \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: seedance-25-001" \
  -d '{
    "model": "seedance-2.5",
    "prompt": "A vertical UGC-style product clip on a desk, natural light",
    "resolution": "720p",
    "duration": 15
  }'

Cost and queueing

The workspace USD balance is reserved on submit at provider list price times 1.25, and usage.cost on the poll response is the billable amount. Extra jobs beyond your processing concurrency are accepted as queued while queue capacity remains.