bytedance/seedance-2.5

Seedance 2.5 — the large-input, long-output member of the family.

Up to 30 reference images, 10 reference clips and 10 audio tracks, audio-only input, and output up to 30 seconds.

Not a cheaper successor to 2.0 — the most expensive model in the family.

Slug	bytedance/seedance-2.5
Kind	video
Vendor	bytedance
Endpoint	POST /v1/byteplus/contents/generations/tasks

Charged per job from what the generator reports it rendered — your Logs show the exact figure for each one; see balance and billing.

Calling it

curl https://api.sociaro.com/v1/byteplus/contents/generations/tasks \
  -H "Authorization: Bearer $SOCIARO_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
        "model": "bytedance/seedance-2.5",
        "prompt": "a paper boat on a rain-soaked street",
        "resolution": "720p",
        "duration": 5
      }'

# then poll the job id it returns:
curl https://api.sociaro.com/v1/byteplus/contents/generations/tasks/JOB_ID \
  -H "Authorization: Bearer $SOCIARO_API_KEY"

Parameters

Seedance 2.5 — the large-input, long-output tier

Anything not listed here is refused rather than ignored, so a typo fails loudly instead of quietly producing something else.

Worked example

# extend an existing clip — duration is the length of the ADDITION
curl https://api.sociaro.com/v1/spicy/generations \
  -H "Authorization: Bearer $SOCIARO_API_KEY" -H "Content-Type: application/json" \
  -d '{ "model": "spicy/seedance-2-5",
        "content": [
          { "type": "text", "text": "the camera drifts on past the lantern" },
          { "type": "video_url", "video_url": {"url": "https://your-cdn.example.com/clip.mp4"},
            "role": "reference_video" }
        ],
        "omni_reference_task_type": "extend",
        "resolution": "1080p", "duration": 6 }'

Not a cheaper successor to 2.0 — the most expensive model in the family. What it buys is scale of input and length of output:

Metered per token, with the same minimum cost on video-input jobs as the rest of the family.

1080p arrived on 2026-08-14 and 4K is still unpriced by the vendor, so 4K is a 400. The tier list on this page is read from what BytePlus prices, so it changes when they publish one.

omni_reference_task_type exists on this model alone. The 2.0 rows accept it and ignore it, which buys you a clip that never used the setting and no error saying so.

How a job runs

These routes are a pass-through: you send BytePlus's own body and get their own response back, with our additions beside it. Generation takes longer than a request should wait, so it goes in three moves — submit, poll, collect.

# 1. submit — the id comes back as `id`. There is NO `job_id` on THIS response
curl -sS https://api.sociaro.com/v1/byteplus/contents/generations/tasks \
  -H "Authorization: Bearer $SOCIARO_API_KEY" -H "Content-Type: application/json" \
  -d '{ "model": "…", "content": [ … ] }'
# -> { "id": "cgt-…" }

# 2. poll every 5-10 s
curl -sS https://api.sociaro.com/v1/byteplus/contents/generations/tasks/cgt-… \
  -H "Authorization: Bearer $SOCIARO_API_KEY"
# -> { "status": "running", … }
# -> { "status": "succeeded", "content": { "video_url": "<the vendor's own link>" },
#      "media_url": "https://api.sociaro.com/v1/media/<media_id>" }

# 3. collect — the opaque id IS the credential, no header needed
curl -sSL "https://api.sociaro.com/v1/media/<media_id>" -o out.mp4

Images use POST /v1/byteplus/images/async and its poll in the same shape, and the faster models also answer synchronously at POST /v1/byteplus/images/generations — one request, the picture in the response. A model whose render outlasts the gateway's ~2-minute ceiling is refused there by name, telling you to use the async route.

Reading the poll

Two differences will bite a client written against the poll-style routes. The SUBMIT returns id, not job_id — code reading job_id there gets nothing and cannot poll at all. And status is the VENDOR'S vocabulary: running, succeeded, failed — not processing, completed, failed. A check for completed on this route never becomes true, which reads as a job that never finishes rather than as an error.

The POLL response does carry job_id beside the vendor's id, as a convenience, and it returns the vendor's whole body — around twenty fields — rather than the five-field shape the other routes use. Gate on status rather than on the poll's HTTP code.

Prefer media_url over the vendor's raw link. Both are returned: content.video_url (or data[].url for images) is theirs, kept for compatibility and due to be removed once nobody reads it; media_url is ours. Ours points at our host, hides the vendor's storage, and expires. A second asset arrives on the same terms — return_last_frame gives content.last_frame_url with last_frame_media_url beside it.

Collecting the result

media_url is a capability: the opaque id is the credential, so no Authorization header is needed and anyone holding the link can fetch it. It expires within the hour — download rather than store the link.

Rules the gateway adds

Your key must be granted this model — 403 otherwise — and either spelling satisfies the grant: our catalogue id or the vendor's own native one.

Because this is a pass-through, unknown fields go to the generator rather than being refused here, and it is the generator that decides. The exception is resolution, which we check ourselves: an unsupported tier is silently ignored upstream, so you would ask for the higher one, be handed a lower one, and be charged. A tier we cannot price is refused at submit, before any money is spent, with a message naming the ones this model has.

Ranges and enums are the generator's own, so an out-of-range value comes back as its rejection, in its wording and with its numbers.