HappyHorse-1.1-R2V - Generate Video (AI Model · By )

API Documentation

API Reference

Videos

Generate Video

Supported Model Code

Loading models...

HappyHorse-1.1-R2V (happyhorse-1.1-r2v)

happyhorse-1.1-r2v0 models support this endpoint

HappyHorse 1.1 Reference-to-Video composes a video from the characters, objects, and styles you supply. Upload 1 to 9 reference images and weave them into one scene through your prompt, calling each out in order with tags like [Image 1], [Image 2] — "the woman in the red qipao from [Image 1] sways the tassel earrings from [Image 3] while unfolding the fan from [Image 2]." HappyHorse keeps each subject consistent while it stages their actions and interactions into coherent motion. Choose from nine aspect ratios, output at 720P or 1080P for 3 to 15 seconds with an optional watermark — perfect for character-driven storytelling, virtual try-on, and bringing your own assets together in a single shot.

Generate video

https://api.modelstream.ai

POST/v1/video/generations

Authentication

BearerAuth

AuthenticationBearer <token>

All API requests must be authenticated using a Bearer token in the Authorization header. Please ensure your API key is active.Authorization: Bearer sk-xxxxxx

Parameter Location: Header Param

Request Body

application/json

These parameters come from the selected model form_schema. Switching models updates this list and the request example.

images*array

Required. Upload 1-9 reference images and reference them in order with [Image 1], [Image 2]... in the prompt. Supports JPEG, JPG, PNG, WEBP; short edge ≥400px (720P+ recommended), each image ≤20MB.

RequiredExample Value: ["https://static.modelstream.ai/demo/happyhorse/happyhorse-1.0-r2v_Reference.png","https://help-static-aliyun-doc.aliyuncs.com/file-manage-files/zh-CN/20260424/fvuihk/hh-v2v2-folding-fan.jpg","https://help-static-aliyun-doc.aliyuncs.com/file-manage-files/zh-CN/20260424/imerii/hh-v2v-earrings.jpg"]Value Range: 1 ≤ value ≤ 9

prompt*string

Required. Describe the actions and scene details of the reference subjects; reference images in order with [Image 1], [Image 2].... Up to 2500 Chinese characters or 5000 non-Chinese characters.

RequiredExample Value: The woman in a red cheongsam from [Image 1] gracefully sways her tassel earrings from [Image 3] as she turns her head while unfolding a folding fan from [Image 2], exuding an oriental charm.Placeholder: Describe the actions of the reference subjects in the scene, referencing with [Image 1]...

ratio?string

Video aspect ratio; options 16:9, 9:16, 1:1, 4:3, 3:4, 4:5, 5:4, 21:9, 9:21. Default 16:9.

Example Value: 16:9

Enum/Options:

16:99:161:14:33:44:55:421:99:21

resolution?string

Video output resolution; options 720P, 1080P, default 1080P.

Example Value: 1080P

Enum/Options:

1080P720P

duration?number

Video duration in seconds; range 3-15 seconds, default 5.

Example Value: 5Value Range: 3 ≤ value ≤ 15step: 1

watermark?boolean

Whether to add the "Happy Horse" watermark to the bottom-right of the video. Enabled by default.

Example Value: true

seed?number

Random seed, range [0, 2147483647]. A fixed integer improves reproducibility; leave empty for a random seed.

Placeholder: Empty for randomValue Range: 0 ≤ value ≤ 2147483647

Response Parameters

application/json

200apiDocs.responses.successCreateVideoGenTask

task_id?string

Parameter description for Task Id

status?string

Parameter description for Status

400apiDocs.responses.badRequestParams

error?object

Parameter description for Error

message?string

Error Message

type?string

Error Type

param?string

Related Parameters

code?string

Error Code

curl -X POST "https://api.modelstream.ai/v1/video/generations" \
  -H "Authorization: Bearer <token>" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "happyhorse-1.1-r2v",
  "prompt": "The woman in a red cheongsam from [Image 1] gracefully sways her tassel earrings from [Image 3] as she turns her head while unfolding a folding fan from [Image 2], exuding an oriental charm.",
  "size": "1080P",
  "duration": 5,
  "metadata": {
    "input": {
      "media": [
        {
          "type": "reference_image",
          "url": "https://static.modelstream.ai/demo/happyhorse/happyhorse-1.0-r2v_Reference.png"
        },
        {
          "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": {
      "ratio": "16:9",
      "watermark": true
    }
  }
}'

{
  "task_id": "abcd1234efgh",
  "status": "queued"
}

API Documentation

API Reference

Videos

Generate Video

Supported Model Code

Loading models...

HappyHorse-1.1-R2V (happyhorse-1.1-r2v)

happyhorse-1.1-r2v0 models support this endpoint

Generate video

https://api.modelstream.ai

POST/v1/video/generations

Authentication

BearerAuth

AuthenticationBearer <token>

All API requests must be authenticated using a Bearer token in the Authorization header. Please ensure your API key is active.Authorization: Bearer sk-xxxxxx

Parameter Location: Header Param

Request Body

application/json

These parameters come from the selected model form_schema. Switching models updates this list and the request example.

images*array

prompt*string

Required. Describe the actions and scene details of the reference subjects; reference images in order with [Image 1], [Image 2].... Up to 2500 Chinese characters or 5000 non-Chinese characters.

ratio?string

Video aspect ratio; options 16:9, 9:16, 1:1, 4:3, 3:4, 4:5, 5:4, 21:9, 9:21. Default 16:9.

Example Value: 16:9

Enum/Options:

16:99:161:14:33:44:55:421:99:21

resolution?string

Video output resolution; options 720P, 1080P, default 1080P.

Example Value: 1080P

Enum/Options:

1080P720P

duration?number

Video duration in seconds; range 3-15 seconds, default 5.

Example Value: 5Value Range: 3 ≤ value ≤ 15step: 1

watermark?boolean

Whether to add the "Happy Horse" watermark to the bottom-right of the video. Enabled by default.

Example Value: true

seed?number

Random seed, range [0, 2147483647]. A fixed integer improves reproducibility; leave empty for a random seed.

Placeholder: Empty for randomValue Range: 0 ≤ value ≤ 2147483647

Response Parameters

application/json

200apiDocs.responses.successCreateVideoGenTask

task_id?string

Parameter description for Task Id

status?string

Parameter description for Status

400apiDocs.responses.badRequestParams

error?object

Parameter description for Error

message?string

Error Message

type?string

Error Type

param?string

Related Parameters

code?string

Error Code

curl -X POST "https://api.modelstream.ai/v1/video/generations" \
  -H "Authorization: Bearer <token>" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "happyhorse-1.1-r2v",
  "prompt": "The woman in a red cheongsam from [Image 1] gracefully sways her tassel earrings from [Image 3] as she turns her head while unfolding a folding fan from [Image 2], exuding an oriental charm.",
  "size": "1080P",
  "duration": 5,
  "metadata": {
    "input": {
      "media": [
        {
          "type": "reference_image",
          "url": "https://static.modelstream.ai/demo/happyhorse/happyhorse-1.0-r2v_Reference.png"
        },
        {
          "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": {
      "ratio": "16:9",
      "watermark": true
    }
  }
}'

{
  "task_id": "abcd1234efgh",
  "status": "queued"
}

HappyHorse-1.1-R2V - Generate Video (AI Model · By ) | ModelStream