happyhorse-1.1-r2v API

Use the exact model ID happyhorse-1.1-r2v. The model field must match this page exactly.

Sample outputhappyhorse-1.1-r2vPOST /v1/videos5.2s

Parameters: duration=5resolution=1080pratio=16:9Input image

Prompt: One continuous take, no cuts. Keep the woman in the crimson satin coat and the peeling carpet ribbons from the reference and move the event outdoors: she walks out of a revolving door onto a wet plaza and the patterned ribbons keep tearing up behind her, now lifting off the paving stones and streaming out across the square in a long coloured wake. The camera tracks backward ahead of her at waist height and cranes up as the wake spreads. One hard green sign light above the door, warm street lamps across the plaza. Real weight and inertia, satin and wet stone, no text.

Request that produced this sample, with the input media URL replaced

{
  "model": "happyhorse-1.1-r2v",
  "prompt": "One continuous take, no cuts. Keep the woman in the crimson satin coat and the peeling carpet ribbons from the reference and move the event outdoors: she walks out of a revolving door onto a wet plaza and the patterned ribbons keep tearing up behind her, now lifting off the paving stones and streaming out across the square in a long coloured wake. The camera tracks backward ahead of her at waist height and cranes up as the wake spreads. One hard green sign light above the door, warm street lamps across the plaza. Real weight and inertia, satin and wet stone, no text.",
  "seconds": "5",
  "duration": 5,
  "resolution": "1080p",
  "ratio": "16:9",
  "aspect_ratio": "16:9",
  "image": "https://example.com/input-image.png"
}

Authentication and endpoint

Use a Modelflare API key with https://modelflare.dev/v1. The gateway entry point is POST /v1/videos.

HTTP

Authorization: Bearer YOUR_MODELFLARE_API_KEY

Create a task

bash

curl https://modelflare.dev/v1/videos \
  -H "Authorization: Bearer YOUR_MODELFLARE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "happyhorse-1.1-r2v",
    "input": {"prompt": "The person in [Image 1] picks up [Image 2].", "media": [{"type": "reference_image", "url": "https://example.com/person.jpg"}, {"type": "reference_image", "url": "https://example.com/object.jpg"}]},
    "parameters": {"resolution": "1080P", "ratio": "16:9", "duration": 5, "watermark": false}
  }'

Poll and download

Save the task ID. Poll GET /v1/videos/{task_id} and download with GET /v1/videos/{task_id}/content. Result URLs may expire, so transfer the file promptly.

bash

curl https://modelflare.dev/v1/videos/TASK_ID \
  -H "Authorization: Bearer YOUR_MODELFLARE_API_KEY"

Request notes

HappyHorse uses input.prompt; choose the input.media shape that matches the t2v, i2v, or r2v model ID.

Request parameters

HappyHorse R2V places 1–9 reference_image items in input.media and references them in order from the prompt.

Field	Required	Notes
model	Yes	happyhorse-1.1-r2v
input.prompt	Yes	Text description or reference instructions, up to 5,000 non-Chinese or 2,500 Chinese characters
input.media[]	Yes	1–9 reference_image items; public URL or Base64, under 20 MB, minimum 400px short side
parameters.resolution	No	720P / 1080P, default 1080P
parameters.ratio	No	16:9 / 9:16 / 1:1 / 4:3 / 3:4 / 4:5 / 5:4 / 9:21 / 21:9, default 16:9
parameters.duration	No	3–15 seconds, default 5
parameters.watermark	No	Whether to add the HappyHorse watermark
parameters.seed	No	Optional seed from 0 to 2,147,483,647

Input and output limits

R2V uses 1–9 reference_image items and refers to them in prompt order as Image 1, Image 2, and so on. Prompts are limited to 5,000 non-Chinese or 2,500 Chinese characters; images are under 20 MB with a 400px minimum short side.

Errors and failed tasks

Invalid model parameters return a 4xx with a request ID. An asynchronous task can also enter failed after creation succeeds; use error_code and error_message from the poll response as the final task reason. Do not retry the same request with a different JSON shape.

Supported scope

This page covers Modelflare model generation and editing calls. Search or map enrichment, voice management, and element-library management are resource APIs outside this public model-call surface and are not required request fields.

Pricing and billing

This model uses per-second video billing. See the model pricing page for the current customer price, reference list price, and complete specification.

Note

This page documents Modelflare’s public interface; the fields and limits shown here are the current contract.