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POST
Seedance 2.5 Extend
seedance-2.5-extend is the video extension mode model of Seedance 2.5: it continues one to three source clips, up to 1080p. Confirm live rates on the models page.
string
required
Set to seedance-2.5-extend.
string
required
Describe the subject, action, camera movement, lighting, and audio intent.
string
default:"10"
Output length: 4 to 30 seconds.
string
One of adaptive. adaptive follows the input image or video. Send it explicitly; do not send a pixel size.
string
default:"720p"
One of 480p, 720p, 1080p. The price depends on the resolution.
string[]
required
One to 3 public source or reference clips, each up to 50 MB (MP4, MOV). The gateway reads each clip’s length from its MP4/MOV header with HTTP range requests and bills that length, rounded up to whole seconds (up to 15 s). Host clips where range requests work, such as S3, R2, or most CDNs; a clip that cannot be measured bills 15 s.
boolean
default:"true"
Set to false for a silent video.

Request

The response returns a queued task id. Poll and download with the same model:
See the Video API workflow for polling intervals, webhooks, and failure handling.

Price examples

Media inputs must be public http or https URLs. Private network addresses and local files are rejected. Failed generations are not charged.