Name: Seedance 1.5 Pro API: Text to Video with Audio
Brand: magicapi
SKU: api-magicapi-audio-video-follow-instructions-bytedance-seedance-1-5-pro
Availability: InStock
Author: API Market

Shashank Agarwal

# 🎬 Text-to-Video and Image-to-Video Generator with Audio API (ByteDance Seedance 1.5 Pro)

## Overview
Seedance 1.5 Pro is a video generation model from ByteDance. Its developer describes it as a joint audio-video model that accurately follows complex instructions.

Send a text `prompt` to generate a video, or add a start frame `image` (and optionally a `last_frame_image`) for image-to-video. With `generate_audio` on (the default), the video comes with audio that matches the visuals, such as music, sound effects and dialogue described in the prompt. Choose a `duration` from 2 to 12 seconds and a `resolution` of 480p, 720p or 1080p. Each request returns the URL of one MP4 video.

## Features
- **Video with audio**: `generate_audio` (default `true`) adds synchronized music, sound effects and speech; set it to `false` for a silent, cheaper video.
- **Text to video and image to video**: start from a prompt alone or from a start frame `image`.
- **First and last frame**: add `last_frame_image` together with `image` to set how the clip ends.
- **Duration**: 2 to 12 seconds (default 5), at 24 fps.
- **Resolution**: `480p`, `720p` (default) or `1080p`.
- **Aspect ratios**: `16:9` (default), `4:3`, `1:1`, `3:4`, `9:16`, `21:9`, `9:21`; ignored when an image is used.
- **Camera and seed**: `camera_fixed` keeps the camera still; `seed` makes results reproducible.

## Use Cases
1. **Short ads and social clips**: vertical `9:16` or square videos with music and voice lines.
2. **Storyboards and trailers**: cinematic scenes with camera moves, sound design and dialogue.
3. **Animating images**: bring a product photo or illustration to life from a start frame.
4. **Scene transitions**: control the opening and closing frames with `image` and `last_frame_image`.

## Visual Examples
### Example Input
Prompt: "A young astronaut in a worn spacesuit sits in the dim cockpit of a spacecraft. The helmet visor is covered with fog and scratches, and the control panel flickers with orange-yellow lights, creating a tense and lonely atmosphere. The video begins with this static opening frame. The camera then rapidly zooms into the astronaut’s face before cutting to the exterior, revealing the spacecraft racing through a blizzard-like storm of cosmic debris. Sci-fi thriller style. Background music: low electronic synthesizers paired with rapidly swelling strings to build suspense. Sound effects: urgent engine hums and howling space-storm noise. Dialogue: \"In the void of space, one wrong move...\" followed by a brief silence, ending with: \"Mayday... systems failing.\""

Sent with `duration` `5`, `aspect_ratio` `16:9`, `fps` `24`, `camera_fixed` `false` and `generate_audio` `true`; `resolution` was left at `720p` and no image was sent.

### Example Output
[Watch the example output](https://blog.api.market/wp-content/uploads/2026/10/seedance-1-5-pro-output-cpna5r1x-api-market.mp4) (5 seconds, 720p, with audio)

## Input Parameters
| Field | Type | Required | Default | Allowed values | Description |
| --- | --- | --- | --- | --- | --- |
| `prompt` | string | Yes |  |  | Text prompt for video generation. Describe the scene, camera, music, sound effects and dialogue |
| `image` | string (URL) | No | none |  | Start frame image URL for image-to-video generation |
| `last_frame_image` | string (URL) | No | none |  | Last frame image URL. Only works when a start frame image is given too |
| `duration` | integer | No | `5` | `2` to `12` | Video duration in seconds |
| `resolution` | string | No | `720p` | `480p`, `720p`, `1080p` | Video resolution |
| `aspect_ratio` | string | No | `16:9` | `16:9`, `4:3`, `1:1`, `3:4`, `9:16`, `21:9`, `9:21` | Video aspect ratio. Ignored if an image is used |
| `fps` | integer | No | `24` | `24` | Frame rate (frames per second) |
| `camera_fixed` | boolean | No | `false` |  | Whether to fix the camera position |
| `generate_audio` | boolean | No | `true` |  | Generate audio synchronized with the video. When enabled, the output video has audio that matches the visuals |
| `seed` | integer | No | none |  | Random seed. Set it for reproducible generation |

`fps` accepts only `24`. `aspect_ratio` is ignored when `image` is set.

## Pricing
- **Pay As You Go (PAYG) pricing**: you only pay for what you use.
- **Price**: $0.017 per API unit.
- **1 API unit = 1 second of output video, times the factor of the matching tier**, billed on the requested `duration`. Each request is rounded up to a whole API unit.
- The tier depends on `resolution` and `generate_audio`. Price per second of video:

  | `resolution` | `generate_audio`: `false` | `generate_audio`: `true` |
  | --- | --- | --- |
  | `480p` | $0.017 (factor 1) | $0.032691 (factor 1.923) |
  | `720p` | $0.034 (factor 2) | $0.068 (factor 4) |
  | `1080p` | $0.078455 (factor 4.615) | $0.156927 (factor 9.231) |

- When the fields are omitted, `resolution` is `720p` and `generate_audio` is `true`, so the default price is **$0.068 per second** ($0.34 for the default 5 seconds).
- **Example cost**: the example asked for 5 seconds at 720p with audio: 5 x 4 = 20 API units = **$0.34**.
- **Failed or cancelled predictions are not billed.**
- **GET requests to check prediction status** are free and don't count toward API unit usage.
- **No monthly subscription fee.**

## API Documentation

### Base URL
All API requests go to: `https://prod.api.market/api/v1/magicapi/audio-video-follow-instructions-bytedance-seedance-1-5-pro`

### Authentication
Send your api.market API key in the `x-api-market-key` header:
```
x-api-market-key: YOUR_API_MARKET_KEY
```

### Asynchronous Processing
**IMPORTANT**: This API is asynchronous. The flow is:
1. Send a POST request to `/predictions`. A successful request returns **201 Created** with a prediction `id` and a `status` of `starting` or `processing`.
2. Poll GET `/predictions/{id}` with that ID.
3. Keep polling while `status` is `starting` or `processing`.
4. Stop when `status` is `succeeded` (read `output`), `failed` or `canceled` (read `error`).

A polling interval of 5 seconds and an overall timeout of 900 seconds (15 minutes) work well. The example 5-second 720p video with audio took about 59 seconds.

### Endpoints

#### Create a Prediction
```bash
curl -X POST "https://prod.api.market/api/v1/magicapi/audio-video-follow-instructions-bytedance-seedance-1-5-pro/predictions" \
  -H "Content-Type: application/json" \
  -H "x-api-market-key: YOUR_API_MARKET_KEY" \
  -d '{
    "version": "bytedance/seedance-1.5-pro",
    "input": {
      "fps": 24,
      "prompt": "A young astronaut in a worn spacesuit sits in the dim cockpit of a spacecraft. The helmet visor is covered with fog and scratches, and the control panel flickers with orange-yellow lights, creating a tense and lonely atmosphere. The video begins with this static opening frame. The camera then rapidly zooms into the astronaut’s face before cutting to the exterior, revealing the spacecraft racing through a blizzard-like storm of cosmic debris. Sci-fi thriller style. Background music: low electronic synthesizers paired with rapidly swelling strings to build suspense. Sound effects: urgent engine hums and howling space-storm noise. Dialogue: \"In the void of space, one wrong move...\" followed by a brief silence, ending with: \"Mayday... systems failing.\"",
      "duration": 5,
      "aspect_ratio": "16:9",
      "camera_fixed": false,
      "generate_audio": true
    }
  }'
```

Response (201 Created):
```json
{
  "id": "cpna5r1xn1rmw0d1c6rbvy90m4",
  "version": "bytedance/seedance-1.5-pro",
  "status": "starting",
  "created_at": "2026-10-22T03:38:22.672Z"
}
```

#### Check Prediction Status
```bash
curl -X GET "https://prod.api.market/api/v1/magicapi/audio-video-follow-instructions-bytedance-seedance-1-5-pro/predictions/{id}" \
  -H "x-api-market-key: YOUR_API_MARKET_KEY"
```

Response when the prediction has finished (200 OK):
```json
{
  "id": "cpna5r1xn1rmw0d1c6rbvy90m4",
  "status": "succeeded",
  "output": "https://blog.api.market/wp-content/uploads/2026/10/seedance-1-5-pro-output-cpna5r1x-api-market.mp4",
  "error": null,
  "created_at": "2026-10-22T03:38:22.672Z",
  "started_at": "2026-10-22T03:38:23.672Z",
  "completed_at": "2026-10-22T03:39:22.283Z"
}
```

`output` is a single URL string pointing to the generated MP4 video.

### Status Codes
- **201 Created**: prediction created (POST `/predictions`). This is the normal success response.
- **200 OK**: prediction details returned (GET `/predictions/{id}`).
- **400 Bad Request**: invalid input, for example a missing `prompt`, a `duration` outside 2 to 12, or a `resolution` that is not in the list.
- **401 Unauthorized**: missing or invalid API key.
- **404 Not Found**: no prediction with that ID.
- **429 Too Many Requests**: rate limit exceeded.
- **500 Internal Server Error** or **503 Service Unavailable**: temporary server problem; retry later.

## Rate Limits
All plans allow 10 requests per second. Requests above that return `429 Too Many Requests`; back off before retrying and honour any `Retry-After` header. Polling a prediction with GET is free but still counts toward the per-second limit, so poll every 1 to 5 seconds rather than in a tight loop.
## Error Handling
- Check the HTTP status code of every request and read the response body for the error message.
- A prediction can also end with `status` set to `failed`; the `error` field then explains why. Failed predictions are not billed.
- Retry 429, 500 and 503 responses with exponential backoff. Fix the input before retrying a 400.

## Implementation Guide
### Example Code

#### JavaScript
```javascript
const apiKey = "YOUR_API_MARKET_KEY";
const baseUrl = "https://prod.api.market/api/v1/magicapi/audio-video-follow-instructions-bytedance-seedance-1-5-pro";

async function createAndWaitForPrediction(input) {
  const response = await fetch(`${baseUrl}/predictions`, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      "x-api-market-key": apiKey
    },
    body: JSON.stringify({ version: "bytedance/seedance-1.5-pro", input })
  });

  if (response.status !== 201) {
    throw new Error(`API error: ${response.status} ${await response.text()}`);
  }

  const prediction = await response.json();
  return pollForResults(prediction.id);
}

const delay = (ms) => new Promise((resolve) => setTimeout(resolve, ms));

async function pollForResults(predictionId) {
  const maxTimeout = 900000;
  const pollInterval = 5000;
  const startTime = Date.now();

  while (Date.now() - startTime < maxTimeout) {
    const response = await fetch(`${baseUrl}/predictions/${predictionId}`, {
      headers: { "x-api-market-key": apiKey }
    });

    if (!response.ok) {
      throw new Error(`API error: ${response.status} ${await response.text()}`);
    }

    const prediction = await response.json();

    if (prediction.status === "succeeded") {
      return prediction.output;
    }

    if (prediction.status === "failed" || prediction.status === "canceled") {
      throw new Error(`Prediction ${prediction.status}: ${prediction.error || "Unknown error"}`);
    }

    await delay(pollInterval);
  }

  throw new Error("Prediction timed out after 15 minutes");
}

createAndWaitForPrediction({
  "fps": 24,
  "prompt": "A young astronaut in a worn spacesuit sits in the dim cockpit of a spacecraft. The helmet visor is covered with fog and scratches, and the control panel flickers with orange-yellow lights, creating a tense and lonely atmosphere. The video begins with this static opening frame. The camera then rapidly zooms into the astronaut’s face before cutting to the exterior, revealing the spacecraft racing through a blizzard-like storm of cosmic debris. Sci-fi thriller style. Background music: low electronic synthesizers paired with rapidly swelling strings to build suspense. Sound effects: urgent engine hums and howling space-storm noise. Dialogue: \"In the void of space, one wrong move...\" followed by a brief silence, ending with: \"Mayday... systems failing.\"",
  "duration": 5,
  "aspect_ratio": "16:9",
  "camera_fixed": false,
  "generate_audio": true
}).then((output) => console.log(output));
```

#### Python
```python
import time
import requests

API_KEY = "YOUR_API_MARKET_KEY"
BASE_URL = "https://prod.api.market/api/v1/magicapi/audio-video-follow-instructions-bytedance-seedance-1-5-pro"


def create_and_wait_for_prediction(input_data):
    headers = {"Content-Type": "application/json", "x-api-market-key": API_KEY}
    response = requests.post(
        f"{BASE_URL}/predictions",
        headers=headers,
        json={"version": "bytedance/seedance-1.5-pro", "input": input_data},
    )

    if response.status_code != 201:
        raise Exception(f"API error: {response.status_code} {response.text}")

    return poll_for_results(response.json()["id"])


def poll_for_results(prediction_id):
    max_timeout = 900
    poll_interval = 5
    headers = {"x-api-market-key": API_KEY}
    start_time = time.time()

    while time.time() - start_time < max_timeout:
        response = requests.get(f"{BASE_URL}/predictions/{prediction_id}", headers=headers)

        if response.status_code != 200:
            raise Exception(f"API error: {response.status_code} {response.text}")

        prediction = response.json()

        if prediction["status"] == "succeeded":
            return prediction["output"]

        if prediction["status"] in ("failed", "canceled"):
            raise Exception(f"Prediction {prediction['status']}: {prediction.get('error') or 'Unknown error'}")

        time.sleep(poll_interval)

    raise Exception("Prediction timed out after 15 minutes")


output = create_and_wait_for_prediction({
    "fps": 24,
    "prompt": "A young astronaut in a worn spacesuit sits in the dim cockpit of a spacecraft. The helmet visor is covered with fog and scratches, and the control panel flickers with orange-yellow lights, creating a tense and lonely atmosphere. The video begins with this static opening frame. The camera then rapidly zooms into the astronaut’s face before cutting to the exterior, revealing the spacecraft racing through a blizzard-like storm of cosmic debris. Sci-fi thriller style. Background music: low electronic synthesizers paired with rapidly swelling strings to build suspense. Sound effects: urgent engine hums and howling space-storm noise. Dialogue: \"In the void of space, one wrong move...\" followed by a brief silence, ending with: \"Mayday... systems failing.\"",
    "duration": 5,
    "aspect_ratio": "16:9",
    "camera_fixed": False,
    "generate_audio": True
})
print(output)
```

## FAQ
- **How much does a video cost?**
  - Price per second times `duration`: from $0.017 per second (480p, no audio) to $0.156927 per second (1080p, with audio). A default request (5 seconds, 720p, with audio) costs $0.34.
- **How do I make a cheaper video?**
  - Set `generate_audio` to `false` (half the price at 720p and 1080p), lower `resolution`, or shorten `duration`.
- **Can I control the first and last frame?**
  - Yes. Pass the opening frame in `image` and the closing frame in `last_frame_image`. `last_frame_image` only works when `image` is also set.
- **Why is my aspect ratio ignored?**
  - When you send an `image`, the video follows the image and `aspect_ratio` is ignored.
- **How do I add dialogue or sound effects?**
  - Keep `generate_audio` on and describe them in the prompt, for example background music, sound effects and quoted dialogue lines, as in the example.
- **Is the 201 response from POST an error?**
  - No. 201 Created means the prediction was accepted. Use the returned `id` to poll GET `/predictions/{id}` until `status` is `succeeded`, `failed` or `canceled`.

## Contact Us
If you have any questions or need assistance, you can reach out to us through the embedded chat on the bottom right corner of the page or send an email to hello@magicapi.com.


Seedance 1.5 Pro API by ByteDance: text to video and image to video with synced audio, dialogue and sound effects, 2 to 12 seconds at up to 1080p.