Seedance 2.5 Serverless API

Generate cinematic multi-shot AI videos up to 30 seconds with synchronized native audio from text, images, or references.

~312.98s

POST /v2/seedance-2.5 · submit + poll

 1# pip install "segmind>=1.1.0"
 2# export SEGMIND_API_KEY="YOUR_API_KEY"
 3from segmind import SegmindClient, InferenceFailed, InferenceTimeout
 4
 5# Async (v2) — recommended for long-running / video models.
 6# run() blocks up to 600s; submit_async + job.wait(timeout=...) sets a longer
 7# deadline and keeps the request_id so you can re-poll later.
 8client = SegmindClient()                      # reads SEGMIND_API_KEY
 9payload = {
10    "prompt": "The camera slowly pushes in toward the powerful cascading waterfall. Mist drifts and swirls through the golden sunlight, water rushes and splashes over the mossy rocks, and lush ferns sway gently in the breeze while a few birds glide across the gorge. Smooth, steady cinematic camera motion, photorealistic, natural ambient sound of rushing water, gentle wind, and distant birdsong.",
11    "first_frame_url": "https://segmind-resources.s3.amazonaws.com/input/seedance-2.5-firstframe.jpg",
12    "last_frame_url": "",
13    "reference_images": [],
14    "reference_videos": [],
15    "reference_audios": [],
16    "duration": 5,
17    "resolution": "720p",
18    "aspect_ratio": "adaptive",
19    "generate_audio": True,
20    "seed": 42,
21    "return_last_frame": False,
22    "skip_moderation": False,
23    "bitrate_mode": "standard",
24}
25job = client.submit_async("seedance-2.5", **payload)
26print(job.request_id)                         # available immediately
27try:
28    result = job.wait(timeout=900, interval=2.0)
29    print(result["status"])                  # COMPLETED
30    print(result.get("output"))              # model output (e.g. video URL)
31except InferenceTimeout as e:
32    print("still running:", e.request_id)    # re-poll later with this id
33except InferenceFailed as e:
34    print("failed:", e.detail)
35
36# Fast models (<=600s) can use the one-liner instead:
37# result = segmind.run("seedance-2.5", **payload)

 1# pip install "segmind>=1.1.0"
 2# export SEGMIND_API_KEY="YOUR_API_KEY"
 3from segmind import SegmindClient, InferenceFailed, InferenceTimeout
 4
 5# Async (v2) — recommended for long-running / video models.
 6# run() blocks up to 600s; submit_async + job.wait(timeout=...) sets a longer
 7# deadline and keeps the request_id so you can re-poll later.
 8client = SegmindClient()                      # reads SEGMIND_API_KEY
 9payload = {
10    "prompt": "The camera slowly pushes in toward the powerful cascading waterfall. Mist drifts and swirls through the golden sunlight, water rushes and splashes over the mossy rocks, and lush ferns sway gently in the breeze while a few birds glide across the gorge. Smooth, steady cinematic camera motion, photorealistic, natural ambient sound of rushing water, gentle wind, and distant birdsong.",
11    "first_frame_url": "https://segmind-resources.s3.amazonaws.com/input/seedance-2.5-firstframe.jpg",
12    "last_frame_url": "",
13    "reference_images": [],
14    "reference_videos": [],
15    "reference_audios": [],
16    "duration": 5,
17    "resolution": "720p",
18    "aspect_ratio": "adaptive",
19    "generate_audio": True,
20    "seed": 42,
21    "return_last_frame": False,
22    "skip_moderation": False,
23    "bitrate_mode": "standard",
24}
25job = client.submit_async("seedance-2.5", **payload)
26print(job.request_id)                         # available immediately
27try:
28    result = job.wait(timeout=900, interval=2.0)
29    print(result["status"])                  # COMPLETED
30    print(result.get("output"))              # model output (e.g. video URL)
31except InferenceTimeout as e:
32    print("still running:", e.request_id)    # re-poll later with this id
33except InferenceFailed as e:
34    print("failed:", e.detail)
35
36# Fast models (<=600s) can use the one-liner instead:
37# result = segmind.run("seedance-2.5", **payload)

API Endpoint

POSThttps://api.segmind.com/v1/seedance-2.5

Parameters

promptrequired

string

Text describing the video. Use Shot 1:, Shot 2: for multi-shot sequences. Reference uploaded assets as '@Image 1', '@Video 1', '@Audio 1' in your prompt.

aspect_ratiooptional

string

Output aspect ratio. Use 16:9 for landscape, 9:16 for vertical social video, 21:9 for ultrawide cinematic.

Default: "16:9"

Allowed values :

"16:9""9:16""1:1""4:3""3:4""21:9""adaptive"

bitrate_modeoptional

string

Output video encoding bitrate. 'standard' gives smaller files and faster downloads; 'high' produces ~5-6x higher bitrate for better visual fidelity and fewer compression artifacts (larger files). Does not affect price.

Default: "standard"

Allowed values :

Standard→"standard"

High→"high"

durationoptional

integer

Video length in seconds (4-30). Use 5s for quick clips, longer durations for cinematic narratives. Cost scales with duration (token-based).

Default: 5Range: 4 - 30

first_frame_urloptional

string (uri)

Starting frame image URL for image-to-video. Animates outward from this reference. Note: images with real human faces are blocked by ByteDance content policy. Cannot be used together with reference_images.

generate_audiooptional

boolean

Co-generate synchronized audio (dialogue, SFX, ambient, music) in the same pass. Best for scenes with speech, nature sounds, or music.

Default: false

last_frame_urloptional

string (uri)

Ending frame; requires first_frame_url. Guides transitions between two frames.

reference_audiosoptional

string[]

Up to 10 reference audio files (MP3, 2-30 seconds each, 30 seconds combined, max 15MB each). Cite as '@Audio 1' in your prompt. Audio-only reference is supported on seedance-2.5.

reference_imagesoptional

string[]

Up to 30 reference images (max 30MB each) for character/style consistency. Cite as '@Image 1', '@Image 2' in your prompt. Cannot be used together with first_frame_url.

reference_videosoptional

string[]

Up to 10 reference videos (2-30 seconds each, 30 seconds combined, mp4/mov, max 200MB each) for motion/style transfer. Cite as '@Video 1' in your prompt. Requests with reference videos are billed at the video-input token rate.

resolutionoptional

string

Output resolution. seedance-2.5 supports 480p and 720p (24fps). Use 480p for drafts and fast iteration, 720p for final renders. Higher resolution costs more (token-based).

Default: "720p"

Allowed values :

"480p""720p"

return_last_frameoptional

boolean

Returns the final video frame as an image URL. Use to chain clip sequences by passing each final frame as the next first_frame_url.

Default: false

seedoptional

integer

Reproducibility seed. Use -1 for random output, set a fixed value to iterate on the same scene.

Default: 42Range: -1 - 2147483647

skip_moderationoptional

boolean

Bypass BytePlus content moderation pre-filter. Useful when generating artistic content or faces that may trigger false positives. Baseline BytePlus safety policies still apply.

Default: false

Response Type

Returns: Video

Asynchronous requests (v2)

Use Async for video, long-running (>~60s), or high-concurrency workloads; Sync is simplest for fast image & LLM calls. Async submits a request and you poll it to completion.

1
POST /v2/seedance-2.5
Submit — returns request_id, status_url, response_url
2
GET /v2/requests/{id}/status
Poll — until COMPLETED or FAILED
3
GET /v2/requests/{id}
Result — final response body

Status states

QUEUED— Accepted, waiting for a worker

PROCESSING— Running on a worker

COMPLETED— Done — result body is ready

FAILED— Errored (incl. content/RAI blocks)

A FAILED request is served as HTTP 422 — the body still carries the error detail.
An unknown or expired request_id returns HTTP 404.
Results are retained for 1 hour, then expire.
Content / RAI blocks surface as FAILED, not a separate state.
Track completion by polling the status endpoint.

Common Error Codes

The API returns standard HTTP status codes. Detailed error messages are provided in the response body.

400

Bad Request

Invalid parameters or request format

401

Unauthorized

Missing or invalid API key

403

Forbidden

Insufficient permissions

404

Not Found

Model or endpoint not found

406

Insufficient Credits

Not enough credits to process request

429

Rate Limited

Too many requests

500

Server Error

Internal server error

502

Bad Gateway

Service temporarily unavailable

504

Timeout

Request timed out