Seedance 2.0 Fast

Capabilities

Pricing & credits

Video generation is charged in credits based on the billable duration in seconds. Without video input, the billable duration is the output duration; with video input, it also includes the reference video duration.

The table below lists the credits charged per second, not the total cost of a task. The rate depends on the model, output resolution, and whether reference videos are supplied in reference-to-video mode. See the formulas and examples below the table for the total cost calculation.

• Without video input: output seconds × no-video rate.
• With video input: (output seconds + measured reference-video seconds) × with-video rate. The server measures the total reference-video duration and rounds it up to whole seconds before billing.
• Image or audio references alone use the no-video rate. The reference-video billing rate applies only in reference-to-video mode when video references are supplied.

Credits are reserved on submission and charged on success. Failed or timed-out tasks enter the refund flow. A refund_failed billing status means the refund did not complete; check the API logs or contact support.

Authentication

Create an API key in the dashboard. The complete key is shown only once. Keep it on your server and send it as a Bearer token on every request.

https://api.seevio.ai

Authorization: Bearer sk_live_your_api_key
Content-Type: application/json

Set the SEEVIO_API_KEY environment variable before running these examples. JavaScript examples run on your server with Node.js; Python examples use the requests package.

Quickstart

Submit this minimal request, save the returned taskId, then use the task query example below. The credits value in the create response is the reserved amount.

curl --fail-with-body https://api.seevio.ai/v1/videos/generations \
  -H "Authorization: Bearer $SEEVIO_API_KEY" \
  -H "Content-Type: application/json" \
  --data '{
  "model": "seedance-2-0-fast",
  "input": {
    "prompt": "A cat surfing at sunset, cinematic lighting",
    "duration": 5,
    "resolution": "720p",
    "generation_type": "text-to-video",
    "aspect_ratio": "16:9",
    "generate_audio": true
  }
}'

Create task response example

After the request above is accepted, the API returns this JSON response. taskId is the task identifier used for subsequent status queries; credits is the number of credits reserved for this task. This response confirms task creation, not that the video is ready. You need to poll the task status or use a Webhook to receive the video results.

{
  "taskId": "3f2aK9mR7xQp4TnZ8bLc6YwH",
  "credits": 50
}

Create a task

Send a JSON object containing model and input, plus an optional callback_url. Always specify the model ID shown on this page; omitting model selects seedance-2-0.

Request body

Input parameters

Provide image_urls, video_urls and audio_urls as arrays of URL strings (string[]). Every supplied URL must be publicly accessible over HTTPS, including media ignored by the selected mode.

Boolean fields must be JSON true or false, not strings or numbers.

Create response

HTTP 200 returns taskId (string) and credits (number). This acknowledges task creation, not completion. The amount below corresponds to the 5-second 720p quickstart.

{
  "taskId": "3f2aK9mR7xQp4TnZ8bLc6YwH",
  "credits": 50
}

Generation modes & examples

Text to video

Generate from a text prompt. Media URLs are not forwarded in this mode.

curl --fail-with-body https://api.seevio.ai/v1/videos/generations \
  -H "Authorization: Bearer $SEEVIO_API_KEY" \
  -H "Content-Type: application/json" \
  --data '{
  "model": "seedance-2-0-fast",
  "input": {
    "prompt": "A cat surfing at sunset, cinematic lighting",
    "duration": 5,
    "resolution": "720p",
    "generation_type": "text-to-video",
    "aspect_ratio": "16:9",
    "generate_audio": true
  }
}'

First frame

Provide one image as the first frame, then describe the motion in your prompt.

curl --fail-with-body https://api.seevio.ai/v1/videos/generations \
  -H "Authorization: Bearer $SEEVIO_API_KEY" \
  -H "Content-Type: application/json" \
  --data '{
  "model": "seedance-2-0-fast",
  "input": {
    "prompt": "A cat surfing at sunset, cinematic lighting",
    "duration": 5,
    "resolution": "720p",
    "generation_type": "image-to-video",
    "image_urls": [
      "https://example.com/first-frame.jpg"
    ],
    "aspect_ratio": "adaptive"
  }
}'

First and last frames

Provide two image URLs in order: first frame, then last frame. This example also requests the generated video's last frame.

curl --fail-with-body https://api.seevio.ai/v1/videos/generations \
  -H "Authorization: Bearer $SEEVIO_API_KEY" \
  -H "Content-Type: application/json" \
  --data '{
  "model": "seedance-2-0-fast",
  "input": {
    "prompt": "A cat surfing at sunset, cinematic lighting",
    "duration": 5,
    "resolution": "720p",
    "generation_type": "image-to-video",
    "image_urls": [
      "https://example.com/first-frame.jpg",
      "https://example.com/last-frame.jpg"
    ],
    "aspect_ratio": "adaptive",
    "return_last_frame": true
  }
}'

Multimodal reference

Combine image, video and audio references. The prompt remains required. Reference-video input changes the billing formula.

curl --fail-with-body https://api.seevio.ai/v1/videos/generations \
  -H "Authorization: Bearer $SEEVIO_API_KEY" \
  -H "Content-Type: application/json" \
  --data '{
  "model": "seedance-2-0-fast",
  "input": {
    "prompt": "Follow the reference camera movement and keep the character consistent. Use the audio for ambience.",
    "duration": 5,
    "resolution": "720p",
    "generation_type": "reference-to-video",
    "image_urls": [
      "https://example.com/character.jpg"
    ],
    "video_urls": [
      "https://example.com/camera.mp4"
    ],
    "audio_urls": [
      "https://example.com/ambience.mp3"
    ],
    "aspect_ratio": "adaptive"
  }
}'

Query a task

Replace the example ID with the taskId returned by creation. Queries only return tasks owned by the API key's user; inaccessible or unknown IDs return HTTP 404.

Poll every 10–20 seconds as a starting point, back off on HTTP 429 and stop when the status is completed or failed. Prefer webhooks for production. Each code example below performs one query.

curl --fail-with-body https://api.seevio.ai/v1/tasks/3f2aK9mR7xQp4TnZ8bLc6YwH \
  -H "Authorization: Bearer $SEEVIO_API_KEY"

Completed task: query response with video results

When the query returns status=completed, video generation has finished. Read the video URLs from data.results and download them before data.video_expires_at. billing_status=charged indicates that the reserved credits have been charged.

{
  "id": "3f2aK9mR7xQp4TnZ8bLc6YwH",
  "created_at": 1788652800,
  "model": "seedance-2-0-fast",
  "status": "completed",
  "billing_status": "charged",
  "credits": 50,
  "failed_reason": null,
  "data": {
    "results": [
      "https://cdn.seevio.ai/api/videos/example.mp4"
    ],
    "video_expires_at": "2026-09-07T00:00:00Z",
    "last_frame_url": null,
    "processing_time": 48
  }
}

Failed task: query response with failure and billing details

When the query returns status=failed, generation has ended unsuccessfully. Read failed_reason for the cause and billing_status for the refund outcome. In this example, refunded means the credits were returned. credits retains the original reserved amount, and the response does not include data.

{
  "id": "3f2aK9mR7xQp4TnZ8bLc6YwH",
  "created_at": 1788652800,
  "model": "seedance-2-0-fast",
  "status": "failed",
  "billing_status": "refunded",
  "credits": 50,
  "failed_reason": "provider_failed"
}

Webhooks

Set callback_url in the create request to receive a JSON POST when the task completes or fails. Return a 2xx response within 15 seconds. Failed deliveries are retried; process repeated deliveries idempotently by task ID.

Your callback endpoint must accept POST requests with a JSON request body (Content-Type: application/json).

Create a task with a callback

curl --fail-with-body https://api.seevio.ai/v1/videos/generations \
  -H "Authorization: Bearer $SEEVIO_API_KEY" \
  -H "Content-Type: application/json" \
  --data '{
  "model": "seedance-2-0-fast",
  "input": {
    "prompt": "A cat surfing at sunset, cinematic lighting",
    "duration": 5,
    "resolution": "720p",
    "generation_type": "text-to-video",
    "aspect_ratio": "16:9",
    "generate_audio": true
  },
  "callback_url": "https://example.com/webhooks/seevio"
}'

Webhook payloads differ from task query responses: they omit billing_status and credits; failure details are inside data.failed_reason and data.credits_refunded. Webhook created_at is the event creation time in Unix seconds.

Task completed: successful callback payload

When generation succeeds, the callback contains status=completed. Use id to identify the task and data.results to retrieve the video URLs. Download and save the results before data.video_expires_at.

{
  "id": "3f2aK9mR7xQp4TnZ8bLc6YwH",
  "created_at": 1788652800,
  "model": "seedance-2-0-fast",
  "status": "completed",
  "data": {
    "results": [
      "https://cdn.seevio.ai/api/videos/example.mp4"
    ],
    "video_expires_at": "2026-09-07T00:00:00Z",
    "last_frame_url": null,
    "processing_time": 48
  }
}

Task failed: failure callback payload

When generation fails, the callback contains status=failed. Use id to identify the task, data.failed_reason for the failure reason and data.credits_refunded for the number of credits refunded.

{
  "id": "3f2aK9mR7xQp4TnZ8bLc6YwH",
  "created_at": 1788652800,
  "model": "seedance-2-0-fast",
  "status": "failed",
  "data": {
    "failed_reason": "provider_failed",
    "credits_refunded": 50
  }
}

Receiver example

export async function POST(request: Request) {
  const callbackData = await request.json();

  if (callbackData.status === "completed") {
    const videoUrls = callbackData.data.results;
    // Save the video URLs and mark this task as completed in your application.
    console.log(callbackData.id, videoUrls);
  }

  if (callbackData.status === "failed") {
    const { failed_reason, credits_refunded } = callbackData.data;
    // Record the failure reason and refunded credits for this task.
    console.error(callbackData.id, failed_reason, credits_refunded);
  }

  return new Response(null, { status: 200 });
}

This Next.js example reads the JSON callback body and handles completed and failed tasks directly. Add persistence and task-ID deduplication for your application; queue slow work before acknowledging the callback.

Media requirements & limitations

• All media and callback URLs must be public HTTPS URLs. Avoid localhost, private IPs and files that require cookies or login. Reference video/audio URLs must resolve to directly readable media.
• In reference-to-video, provide at least one reference, with no more than 9 images, 3 videos, 3 audio files and 12 materials combined. Total video duration and total audio duration must each be at most 15 seconds.
• text-to-video ignores all media references. image-to-video forwards only the first/last-frame images and ignores video and audio references. Use reference-to-video to combine media.
• For Seedance 2.0 models, use audio with at least one image or video for model compatibility. Audio-only examples are provided on the Seedance 2.5 page.
• Fast and Mini support 480p and 720p. Do not rely on higher resolution strings being accepted at request validation: they are not supported output tiers for this model.

Errors

HTTP errors have an error object with code and message. A successfully accepted task can still fail later; query the task or handle its failure callback.

{
  "error": {
    "code": "invalid_request",
    "message": "input.prompt is required."
  }
}

Rate limits

Create tasks: each API key allows up to 100 requests per minute by default. Custom rate limits are not currently available.

Query tasks: each API key allows up to 120 requests per minute by default. Query requests and task creation requests are counted separately.