ModelStream LogoModelStream Logo
Models
Video API
Image API
Chat API
Audio API
Studio
Pricing
Docs
Menu
IntroductionQuickstartAPI KeysUse with Hermes AgentUse with OpenClaw
Model ListBilling Guide
ModelStream

Video API

  • Seedance 2.0
  • Happyhorse 1.0
  • Vidu Q3
  • Kling V3.0
  • Veo 3.1
  • Wan 2.7
  • More Video Models →

Image API

  • GPT Image 2
  • Nano Banana 2
  • Seedream 5.0
  • Imagen 4
  • Qwen Image 2.0
  • Z-Image Turbo
  • More Image Models →

Audio API

  • Suno Music
  • Qwen3 TTS Flash
  • More Audio Models →

Chat API

  • GLM-5.2
  • Claude Opus 4.8
  • Gemini 3.5 Flash
  • Qwen 3.7 Max
  • GPT 5.5
  • More Chat Models →

About Us

  • Privacy Policy
  • Terms of Service
  • Support
  • Enterprise

© 2026 ModelStream Inc. All rights reserved.

API Documentation
API Reference
Videos
Generate Video

Generate Video

Loading models...
H
HappyHorse-1.0-I2V (happyhorse-1.0-i2v)
happyhorse-1.0-i2v0 models support this endpoint

HappyHorse-1.0-I2V enables image-to-video generation, featuring highly realistic dynamic rendering. It accurately comprehends both text and image semantics to produce high-quality videos that are fluid, natural, and rich in detail. https://bailian.console.alibabacloud.com/cn-beijing?tab=model#/model-market/detail/happyhorse-1.0-i2v?serviceSite=asia-pacific-china

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.

img_url*string

Required. The first frame image; the video aspect ratio automatically follows this image. Supports JPEG, JPG, PNG, WEBP; resolution at least 300×300px, aspect ratio 1:2.5 to 2.5:1, up to 20MB.

RequiredExample Value: https://static.modelstream.ai/demo/happyhorse/happyhorse-1.0-i2v_Reference.pngValue Range: 0 ≤ value ≤ 1
prompt?string

Optional. Describe how you want the image to move. Up to 2500 Chinese characters or 5000 non-Chinese characters.

Example Value: The character slightly turns their head to look at the camera, eyes brimming with emotion, a gentle breeze tousling their hair, the background softly blurred with scattered bokeh lights, as the lens slowly zooms in.Placeholder: Example: Animate the character to gently turn toward the camera. Hair and clothes move softly in the wind, with a slight camera push-in and cinematic lighting.
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: Leave empty for a random seedValue 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-1.0-i2v",
  "prompt": "The character slightly turns their head to look at the camera, eyes brimming with emotion, a gentle breeze tousling their hair, the background softly blurred with scattered bokeh lights, as the lens slowly zooms in.",
  "size": "1080P",
  "duration": 5,
  "metadata": {
    "input": {
      "media": [
        {
          "type": "first_frame",
          "url": "https://static.modelstream.ai/demo/happyhorse/happyhorse-1.0-i2v_Reference.png"
        }
      ]
    },
    "parameters": {
      "watermark": true
    }
  }
}'
{
  "task_id": "abcd1234efgh",
  "status": "queued"
}