Seedance 2.5 Flash

Not yet available. Generate 4–30 second videos at 480p or 720p from text, a first and last frame, or up to 10 reference images and 5 audio clips; a faster, lower-cost sibling of Seedance 2.5.

• A separate model with its own ID, seedance-2.5-flash: a faster, lower-cost sibling of Seedance 2.5, not a mode of seedance-2.5.
• Asynchronous: the create call returns a task ID; the video arrives when the task succeeds.
• Three ways in: text only, a first frame or a first and last frame, or reference images with optional reference audio.
• Reference videos are not supported for now, so there is no video editing or extending; use seedance-2.5 for those.
• Sound is generated by default; MP4 by default, MOV on request.
• Pricing will be announced at launch.

Opens this model in the API Explorer. Enter your BeatAPI API key to create a task: the call is real and is billed to your own balance.

Model IDs

Both Seedance 2.5 models use this endpoint. The values below come from each model’s request contract; Seedance 2.5 Flash does not accept reference_videos or task_type.

Endpoint and authentication

POST https://api.beatapi.io/v1/videos/tasks

Send the body as JSON with Content-Type: application/json. Idempotency-Key is optional: send a unique value (at most 255 characters) per logical request and reuse it only to retry that exact body. Within 24 hours a retry with the same key and body returns the first response again with Idempotent-Replayed: true; the same key with a different body returns 409 idempotency_conflict. Responses other than 2xx are not stored, so a retry after a 400 or 402 runs again.

How a request works

Input modes

Request parameters

The gateway also checks these combinations before creating the task:

• images cannot be combined with reference inputs
• reference_audios need at least one image in reference_images

Input media limits

The gateway reads every input before the task is created and refuses one outside these limits with a 400 bad_request that names the input. Nothing is charged.

• Image size is checked when the host reports it. Use JPEG, PNG or WebP; a file the model cannot use fails the task after submission with bad_request, and the task is refunded.
• Image and audio links are refused at create only when the host answers with a 4xx error or returns an empty file, for example images[1] could not be downloaded: the URL returned HTTP 404.; other problems with them surface after submission.
• Reference videos are not supported for now.
• Have a local file? Upload it with POST /v1/files and pass the returned data.url.

Writing the prompt

Describe the shot: subject, action, camera movement, style and sound. With references, say what each one is for and refer to it by position: @image1 for the first reference image, @image2 for the second, @audio1 for the first reference audio. With frames, @image1 is the first frame and @image2 the last.

Fields this model does not accept

Sending one of these is refused before anything is charged, instead of being ignored:

• reference_videos: reference videos are not supported for now, so a video cannot be edited or extended. Use seedance-2.5 for that.
• task_type: without reference videos there is nothing to edit or extend.
• watermark, quality, sound, multi_shots or character_orientation.
• A name no BeatAPI video model uses → unknown field: <name>.
• duration: -1 (model-chosen length) → "duration" is outside its supported range; send a whole number of seconds.

Request examples

curl --request POST \
  --url https://api.beatapi.io/v1/videos/tasks \
  --header "Authorization: Bearer $BEATAPI_API_KEY" \
  --header 'Content-Type: application/json' \
  --data '{
  "model": "seedance-2.5-flash",
  "prompt": "A slow tracking shot through a rain-lit night market, neon reflections on wet stone, ambient crowd sound",
  "duration": 5,
  "aspect_ratio": "16:9",
  "resolution": "720p"
}'

Text to video

A 5-second 720p landscape clip with sound.

curl --request POST \
  --url https://api.beatapi.io/v1/videos/tasks \
  --header "Authorization: Bearer $BEATAPI_API_KEY" \
  --header 'Content-Type: application/json' \
  --data '{
  "model": "seedance-2.5-flash",
  "prompt": "A slow tracking shot through a rain-lit night market, neon reflections on wet stone, ambient crowd sound",
  "duration": 5,
  "aspect_ratio": "16:9",
  "resolution": "720p"
}'

First and last frame

The video moves from the first image to the second.

curl --request POST \
  --url https://api.beatapi.io/v1/videos/tasks \
  --header "Authorization: Bearer $BEATAPI_API_KEY" \
  --header 'Content-Type: application/json' \
  --data '{
  "model": "seedance-2.5-flash",
  "prompt": "The camera pushes in from the bottle on the table to the singer on a neon stage in one continuous move",
  "images": [
    "https://cdn.beatapi.io/samples/smart-bottle.png",
    "https://cdn.beatapi.io/samples/neon-singer.png"
  ],
  "duration": 6,
  "resolution": "720p"
}'

Image and audio references

A performance that follows a character image and a music clip.

curl --request POST \
  --url https://api.beatapi.io/v1/videos/tasks \
  --header "Authorization: Bearer $BEATAPI_API_KEY" \
  --header 'Content-Type: application/json' \
  --data '{
  "model": "seedance-2.5-flash",
  "prompt": "The singer from @image1 performs on stage in time with @audio1, warm spotlights, slow orbiting camera",
  "reference_images": [
    "https://cdn.beatapi.io/samples/neon-singer.png"
  ],
  "reference_audios": [
    "https://cdn.beatapi.io/samples/neon-singer-preview.mp3"
  ],
  "duration": 8,
  "resolution": "480p"
}'

Responses

Create a task (201)

The task object. output is null until the task succeeds. Fields marked “while running” disappear once the task finishes.

{
  "data": {
    "id": "task_7Qm2Xc9LpR4vT8sKa1Nf6YbH3eWdJ0uZ",
    "object": "task",
    "task_kind": "video",
    "capability_id": "seedance-2.5-flash",
    "capability_version": 1,
    "media_type": "video",
    "model": "seedance-2.5-flash",
    "status": "queued",
    "stage": "queued",
    "created_at": 1791993600,
    "updated_at": 1791993600,
    "completed_at": null,
    "poll_after_seconds": 8,
    "output": null,
    "request_id": "req_5f0c2a9e4b7d4e31",
    "error_code": null,
    "error_message": null
  }
}

Finished task

GET /v1/tasks/{task_id} returns HTTP 200 with status: "succeeded" and the result in data.output.

{
  "data": {
    "id": "task_7Qm2Xc9LpR4vT8sKa1Nf6YbH3eWdJ0uZ",
    "object": "task",
    "task_kind": "video",
    "capability_id": "seedance-2.5-flash",
    "capability_version": 1,
    "media_type": "video",
    "model": "seedance-2.5-flash",
    "status": "succeeded",
    "stage": "succeeded",
    "created_at": 1791993600,
    "updated_at": 1791993690,
    "completed_at": 1791993690,
    "output": {
      "media": [
        {
          "type": "video",
          "url": "https://media.beatapi.io/outputs/task_7Qm2Xc9LpR4vT8sKa1Nf6YbH3eWdJ0uZ/0.mp4",
          "mime_type": "video/mp4"
        }
      ],
      "r2_url": "https://media.beatapi.io/outputs/task_7Qm2Xc9LpR4vT8sKa1Nf6YbH3eWdJ0uZ/0.mp4"
    },
    "request_id": "req_5f0c2a9e4b7d4e31",
    "error_code": null,
    "error_message": null
  }
}

Output fields

Failed task

A failed task is still HTTP 200 on GET /v1/tasks/{task_id}: the failure is in the body. The reservation is returned in full, so nothing is charged.

{
  "data": {
    "id": "task_7Qm2Xc9LpR4vT8sKa1Nf6YbH3eWdJ0uZ",
    "object": "task",
    "task_kind": "video",
    "capability_id": "seedance-2.5-flash",
    "capability_version": 1,
    "media_type": "video",
    "model": "seedance-2.5-flash",
    "status": "failed",
    "stage": "failed",
    "created_at": 1791993600,
    "updated_at": 1791993690,
    "completed_at": 1791993690,
    "output": null,
    "retryable": true,
    "request_id": "req_5f0c2a9e4b7d4e31",
    "error_code": "processing_failed",
    "error_message": "The task failed during processing on our side. Retry; a failed task is refunded."
  }
}

Complete example

Create a task, wait for it with the server’s polling hint, and print the result URLs. Set BEATAPI_API_KEY in your environment and install requests.

import os
import time
import uuid
import requests
API = "https://api.beatapi.io"
HEADERS = {"Authorization": f"Bearer {os.environ['BEATAPI_API_KEY']}"}
def create_task(body: dict) -> dict:
    # One Idempotency-Key per logical request: a retry with the same key cannot create a second task.
    headers = {**HEADERS, "Idempotency-Key": str(uuid.uuid4())}
    for attempt in range(3):
        response = requests.post(f"{API}/v1/videos/tasks", headers=headers, json=body, timeout=60)
        if response.status_code in (429, 503) and attempt < 2:
            time.sleep(int(response.headers.get("Retry-After", 10)))
            continue
        break
    try:
        payload = response.json()
    except ValueError:  # an edge error page is not JSON
        response.raise_for_status()
        raise
    if not response.ok:
        error = payload["error"]
        raise RuntimeError(f"{response.status_code} {error['code']}: {error['message']} (request_id={error.get('request_id')})")
    return payload["data"]
def wait_for_task(task_id: str, timeout_seconds: int = 1800) -> dict:
    deadline = time.monotonic() + timeout_seconds
    while time.monotonic() < deadline:
        response = requests.get(f"{API}/v1/tasks/{task_id}", headers=HEADERS, timeout=30)
        if response.status_code == 429 or response.status_code >= 500:
            time.sleep(int(response.headers.get("Retry-After", 10)))
            continue
        response.raise_for_status()
        task = response.json()["data"]
        if task["status"] in ("succeeded", "failed"):
            return task
        time.sleep(task.get("poll_after_seconds", 5))
    raise TimeoutError(f"task {task_id} is still running; keep polling later")
task = create_task({
  "model": "seedance-2.5-flash",
  "prompt": "A slow tracking shot through a rain-lit night market, neon reflections on wet stone, ambient crowd sound",
  "duration": 5,
  "aspect_ratio": "16:9",
  "resolution": "720p"
})
print("created", task["id"])
task = wait_for_task(task["id"])
if task["status"] == "failed":
    raise SystemExit(f"{task['error_code']}: {task['error_message']}")
for item in task["output"]["media"]:
    print(item["url"])

Billing

• Pricing will be announced at launch. Until then no price is listed here, and requests for this model are not accepted.
• A failed task, including one refused by moderation after submission, is refunded in full.

Common errors

HTTP errors at a glance

Errors before a task exists arrive as a non-2xx response, and nothing is charged. Branch on error.code or error.retryable; message names the problem. The full list and retry policy are on Errors.

{
  "error": {
    "code": "bad_request",
    "message": "\"prompt\" is required",
    "retryable": false,
    "request_id": "req_5f0c2a9e4b7d4e31"
  }
}