HappyHorse - reference-to-video API reference

The HappyHorse reference-to-video model lets you provide multiple reference images and a text prompt to generate a video that combines subjects from the images into a scene based on the prompt.

Usage notes

To ensure successful API calls, you must use a model , endpoint URL , and API key that all belong to the same region. Cross-region calls will fail.

Select a model: Confirm the region where your model is located.
Select a URL: Choose the corresponding endpoint URL. Both HTTP and DashScope SDK URLs are supported.
Configure an API key : Select a region, get an API key, and then configure the API key as an environment variable.

Note

The sample code in this topic applies to the Singapore region.

HTTP calls

Because reference-to-video tasks are time-consuming (typically 1--5 minutes), the API uses an asynchronous call. The workflow consists of two core steps: "Create a task -> Poll for the result".

Step 1: Create a task

Singapore

POST https://dashscope-intl.aliyuncs.com/api/v1/services/aigc/video-generation/video-synthesis

US (Virginia)

POST https://dashscope-us.aliyuncs.com/api/v1/services/aigc/video-generation/video-synthesis

China (Beijing)

POST https://dashscope.aliyuncs.com/api/v1/services/aigc/video-generation/video-synthesis

Germany (Frankfurt)

POST https://{WorkspaceId}.eu-central-1.maas.aliyuncs.com/api/v1/services/aigc/video-generation/video-synthesis

Replace WorkspaceId with your Workspace ID. Note

After the task is created, use the returned task_id to query the result. The task_id is valid for 24 hours. Do not create duplicate tasks. Instead, use polling to retrieve the result.
For guidance for beginners, see Postman.

Request parameters

## Reference-to-video (multi-image)

curl

curl --location 'https://dashscope-intl.aliyuncs.com/api/v1/services/aigc/video-generation/video-synthesis' \\
 -H 'X-DashScope-Async: enable' \\
 -H "Authorization: Bearer $DASHSCOPE_API_KEY" \\
 -H 'Content-Type: application/json' \\
 -d '{
 "model": "happyhorse-1.0-r2v",
 "input": {
 "prompt": "A woman in a red qipao from \[Image 1\] is first shown in a profile medium shot, highlighting the tailored cut and S-curve of the dress. The camera then switches to a low-angle shot, capturing her unfolding the fan from \[Image 2\] while the tassel earrings from \[Image 3\] sway with her head movement. The scene ends with a close-up of her face, focusing on the charm in her eyes as her fingertips touch the fan, showcasing Eastern elegance from multiple angles.",
 "media": \[
 {
 "type": "reference_image",
 "url": "https://help-static-aliyun-doc.aliyuncs.com/file-manage-files/zh-CN/20260424/mvzfud/hh-v2v-girl.jpg"
 },
 {
 "type": "reference_image",
 "url": "https://help-static-aliyun-doc.aliyuncs.com/file-manage-files/zh-CN/20260424/fvuihk/hh-v2v2-folding-fan.jpg"
 },
 {
 "type": "reference_image",
 "url": "https://help-static-aliyun-doc.aliyuncs.com/file-manage-files/zh-CN/20260424/imerii/hh-v2v-earrings.jpg"
 }
 \]
 },
 "parameters": {
 "resolution": "720P",
 "ratio": "16:9",
 "duration": 5
 }
}'

Request headers

Content-Type *string* (Required) The content type of the request. Must be application/json.

Authorization *string* (Required) Authenticates the request with a Model Studio API key. Example: Bearer sk-xxxx.

X-DashScope-Async *string* (Required) Enables asynchronous processing. HTTP requests support only asynchronous calls. Must be enable.

**Important ** If this request header is missing, the error "current user api does not support synchronous calls" is returned.

Request body

model *string* (Required) The name of the model. Set to: happyhorse-1.0-r2v.

input *object* (Required) The model input, which includes the reference images and text prompt. Properties

prompt *string* (Required) A description of the desired elements and visual style for the generated video. Input in any language is supported. The length is limited to 5,000 non-Chinese characters or 2,500 Chinese characters. Content exceeding this limit is automatically truncated. Image referencing: In the prompt, use "[Image 1]" and "[Image 2]" to refer to the corresponding reference image in the media array. The order must be consistent with the order in the media array. When using a reference, specify the object in the image, such as "the woman in a red qipao in [Image 1]".

media *array* (Required) A list of reference images. Each element in the array is a media object that contains type and url fields.

The order of elements in this array defines the order of subject references in the prompt.
The first reference_image in the array corresponds to [Image 1], the second to [Image 2], and so on.

Element properties

type *string* (Required) The type of media asset. Set this to:

reference_image: A reference image. Asset limits:
Number of reference images: 1 to 9.

url *string* (Required) The URL or Base64-encoded data of a reference image. Image requirements:

Formats: JPEG, JPG, PNG, WEBP.
Resolution: The shortest side must be at least 400 pixels. A clear image with a resolution of 720P or higher is recommended. Avoid using images that are too small, blurry, or overly compressed, as this can degrade the output quality.
Maximum file size: 20 MB. Supported input formats:
Public URL: <li> Supports HTTP or HTTPS protocols.
Example: https://xxx/xxx.jpg. </li>
Base64-encoded image string: <li> Data format: data:{MIME_type};base64,{base64_data}.
Example: data:image/png;base64,GDU7MtCZzEbTbmRZ...... (truncated for display purposes). Base64-encoded data format Format: data:{MIME_type};base64,{base64_data} . <li> {base64_data}: The Base64-encoded string of the image file.
{MIME_type}: The media type of the image, which must match the file format.

Image format	MIME Type
JPEG	image/jpeg
JPG	image/jpeg
PNG	image/png
WEBP	image/webp

</li> </li>

parameters *object* (Optional) Parameters for video generation, such as video resolution, aspect ratio, and duration. Properties

resolution *string* (Optional) The resolution tier of the generated video. Valid values:

1080P: Default value.
720P

ratio *string* (Optional) The aspect ratio of the generated video. Valid values:

16:9: Default value.
9:16
3:4
4:3
4:5
5:4
1:1

duration *integer* (Optional) The duration of the generated video, in seconds. Value range: An integer from 3 to 15. Default value: 5.

watermark *boolean* (Optional) Specifies whether to add a watermark to the generated video. The watermark is placed in the bottom-right corner with the fixed text "Happy Horse".

true: Default value. A watermark is added.
false: No watermark is added.

seed *integer* (Optional) The random number seed must be an integer in the range \[0, 2147483647\]. If not specified, a random seed is generated. A fixed seed improves reproducibility. Because model generation is probabilistic, the same seed does not guarantee identical results.

Response parameters

Successful response

Save the task_id to query the task status and result.

json

{
 "output": {
 "task_status": "PENDING",
 "task_id": "0385dc79-5ff8-4d82-bcb6-xxxxxx"
 },
 "request_id": "4909100c-7b5a-9f92-bfe5-xxxxxx"
}

Error response

Task creation failed. See Error messages.

json

{
 "code": "InvalidApiKey",
 "message": "No API-key provided.",
 "request_id": "7438d53d-6eb8-4596-8835-xxxxxx"
}

     **output** `*object*`  The output information for the task.

Properties

task_id *string* The task ID. Valid for queries for 24 hours.

task_status *string* The status of the task. Enumeration values

PENDING
RUNNING
SUCCEEDED
FAILED
CANCELED
UNKNOWN: The task does not exist or its status is unknown.

request_id *string* Unique request identifier for tracing and troubleshooting.

code *string* Error code. Returned only for failed requests. See Error messages.

message *string* Detailed error message. Returned only for failed requests. See Error messages.

Step 2: Get the task result

Singapore

GET https://dashscope-intl.aliyuncs.com/api/v1/tasks/{task_id}

US (Virginia)

GET https://dashscope-us.aliyuncs.com/api/v1/tasks/{task_id}

China (Beijing)

GET https://dashscope.aliyuncs.com/api/v1/tasks/{task_id}

Germany (Frankfurt)

GET https://{WorkspaceId}.eu-central-1.maas.aliyuncs.com/api/v1/tasks/{task_id}

Replace WorkspaceId with your Workspace ID. Note

Polling recommendation : Video generation can take several minutes. We recommend that you implement a polling mechanism with a reasonable query interval (for example, 15 seconds) to retrieve the result.
Task status flow: PENDING (Queued) → RUNNING (Processing) → SUCCEEDED (Succeeded) or FAILED (Failed).
Task ID validity : The task ID is valid for 24 hours . After this period, you can no longer query the result, and the API returns a task status of UNKNOWN.

Request parameters

## Query task result

Replace {task_id} with the task_id value returned by the previous API call. The task_id is valid for queries for 24 hours.

curl

curl -X GET https://dashscope-intl.aliyuncs.com/api/v1/tasks/{task_id} \\
--header "Authorization: Bearer $DASHSCOPE_API_KEY"

Request headers

Authorization *string* (Required) Authenticates the request with a Model Studio API key. Example: Bearer sk-xxxx.

URL path parameters

task_id *string* (Required) The ID of the task.

Response parameters

Task succeeded

Video URLs are valid for only 24 hours and then automatically purged. Save generated videos promptly.

json

{
 "request_id": "35137489-2862-96cb-b6f2-xxxxxx",
 "output": {
 "task_id": "1469cfc3-3004-4d9e-ab10-xxxxxx",
 "task_status": "SUCCEEDED",
 "submit_time": "2026-04-25 15:03:25.848",
 "scheduled_time": "2026-04-25 15:03:25.884",
 "end_time": "2026-04-25 15:04:05.882",
 "orig_prompt": "A woman in a red qipao from \[Image 1\] is first shown in a profile medium shot, highlighting the dress'\\''s tailored cut and S-curve. The camera then switches to a low-angle shot, capturing her unfolding the fan from \[Image 2\] while the tassel earrings from \[Image 3\] sway with her head movement. The scene ends with a close-up of her face, focusing on the charm in her eyes as her fingertips touch the fan, showcasing Eastern elegance from multiple angles.",
 "video_url": "https://dashscope-result-intl.oss-ap-southeast-1.aliyuncs.com/xxxx.mp4"
 },
 "usage": {
 "duration": 5,
 "input_video_duration": 0,
 "output_video_duration": 5,
 "video_count": 1,
 "SR": 720,
 "ratio": "16:9"
 }
}

## Task failed

When a task fails, task_status is FAILED with an error code and message. See Error messages.

json

{
 "request_id": "e5d70b02-ebd3-98ce-9fe8-759d7d7b107d",
 "output": {
 "task_id": "86ecf553-d340-4e21-af6e-a0c6a421c010",
 "task_status": "FAILED",
 "code": "InvalidParameter",
 "message": "The resolution is not valid xxxxxx"
 }
}

## Task query expired

The task_id is valid for 24 hours. After this period, queries return the following error.

json

{
 "request_id": "a4de7c32-7057-9f82-8581-xxxxxx",
 "output": {
 "task_id": "502a00b1-19d9-4839-a82f-xxxxxx",
 "task_status": "UNKNOWN"
 }
}

     **output **`*object*`* * The output information for the task.

Properties

task_id *string* The task ID. Valid for queries for 24 hours.

task_status *string* The status of the task. Enumeration values

PENDING
RUNNING
SUCCEEDED
FAILED
CANCELED
UNKNOWN: The task does not exist or its status is unknown.

State transitions during polling:

PENDING → RUNNING → SUCCEEDED or FAILED.
The initial query status is usually PENDING or RUNNING.
When the status changes to SUCCEEDED, the response contains the generated video URL.
If the status is FAILED, check the error message and retry the task.

submit_time *string* The time when the task was submitted. The time is in UTC+8 and the format is YYYY-MM-DD HH:mm:ss.SSS.

scheduled_time *string* The time when the task was executed. The time is in UTC+8 and the format is YYYY-MM-DD HH:mm:ss.SSS.

end_time *string* The time when the task was completed. The time is in UTC+8 and the format is YYYY-MM-DD HH:mm:ss.SSS.

video_url *string* URL of the generated video. Returned only when task_status is SUCCEEDED. Valid for 24 hours. The video is in MP4 format with H.264 encoding.

orig_prompt *string* The original input prompt, corresponding to the request parameter prompt.

code *string* Error code. Returned only for failed requests. See Error messages.

message *string* Detailed error message. Returned only for failed requests. See Error messages.

usage *object* Usage statistics for the task. You are only billed for successful tasks. Properties

duration *integer* The billable duration of the generated video, in seconds.

input_video_duration *integer* The total duration of the input video, in seconds. This is always 0 for reference-to-video tasks.

output_video_duration *integer* The total duration of the output video, in seconds.

ratio *string* The aspect ratio of the generated video.

SR *integer* The resolution tier of the generated video.

video_count *integer* The number of generated videos. This is always 1.

request_id *string* Unique request identifier for tracing and troubleshooting.

Error codes

If the model call fails and returns an error message, see Error messages for resolution.

HappyHorse - reference-to-video API reference ​

Usage notes ​

HTTP calls ​

Step 1: Create a task ​

Singapore ​

US (Virginia) ​

China (Beijing) ​

Germany (Frankfurt) ​

Request parameters ​

## Reference-to-video (multi-image) ​

Request headers ​

Request body ​

Response parameters ​

Successful response ​

Error response ​

Step 2: Get the task result ​

Singapore ​

US (Virginia) ​

China (Beijing) ​

Germany (Frankfurt) ​

Request parameters ​

## Query task result ​

Request headers ​

URL path parameters ​

Response parameters ​

Task succeeded ​

## Task failed ​

## Task query expired ​

Error codes ​

HappyHorse - reference-to-video API reference

Usage notes

HTTP calls

Step 1: Create a task

Singapore

US (Virginia)

China (Beijing)

Germany (Frankfurt)

Request parameters

## Reference-to-video (multi-image)

Request headers

Request body

Response parameters

Successful response

Error response

Step 2: Get the task result

Singapore

US (Virginia)

China (Beijing)

Germany (Frankfurt)

Request parameters

## Query task result

Request headers

URL path parameters

Response parameters

Task succeeded

## Task failed

## Task query expired

Error codes