Use HappyHorse 1.1 through Rivya Public API v1 with model id happyhorse-1-1, supported inputs, parameters, Files API rules, credits, and response examples.

Available via APIText or URL ready; reference modes use Files APIVideo

API model id

happyhorse-1-1

Inputs

text, file

Files API

Required for reference modes

Base credits

per_output_second · 720p=22.5 · 1080p=29 · ⌈total⌉

Capability

Video

Billing

METERED

Prompt limit

5000 characters

Request contract

Send the model id at the top level. Model-specific controls belong in params.

Key	Type	Required	Default	Description
model	string	Yes	happyhorse-1-1	Use the happyhorse-1-1 API model id.
prompt	string	No	-	Maximum 5000 characters for this model.
params	object	No	-	Model-specific parameter object. Use the rows below for allowed keys.
client_request_id	string	No	-	Optional client-side id for tracing requests in your system.

Model parameters

Key	Type	Required	Default	Range	Options	Description
resolution	select	No	1080p	-	720p, 1080p	The selected resolution sets the per-second credit rate.
aspect_ratio	select	No	16:9	-	16:9, 9:16, 1:1, 4:3, 3:4, 4:5, 5:4, 9:21, 21:9	Used for prompt-only and multi-reference runs; a single-image run follows its first frame.
duration	number	No	5	min 3 / max 15 / step 1	-	Choose a whole-number output duration from 3 to 15 seconds.

Upload policy

Upload reference files first, then place the returned URL and duration token inside params.referenceMediaItems.

Reference rule

First frame or reference images: Upload one JPEG, PNG, or WebP image for first-frame animation, or 2 to 9 images for reference-led video. Each file can be up to 20 MB.

Max files

Accepted file kinds

image

Duration token

Video and audio references should carry durationToken from /api/v1/files when duration verification is required.

kind	Max size	MIME types
image	20 MB	image/jpeg, image/png, image/webp

Minimal request

{
  "model": "happyhorse-1-1",
  "prompt": "A cinematic product reveal with smooth camera movement",
  "params": {
    "resolution": "1080p",
    "aspect_ratio": "16:9",
    "duration": 5
  }
}

Reference-file request

{
  "model": "happyhorse-1-1",
  "prompt": "A cinematic product reveal with smooth camera movement",
  "params": {
    "resolution": "1080p",
    "aspect_ratio": "16:9",
    "duration": 5,
    "referenceMediaItems": [
      {
        "url": "https://cdn.example.com/reference-image.png",
        "kind": "image",
        "name": "reference-image.png",
        "mimeType": "image/png",
        "width": 1024,
        "height": 1024,
        "sizeBytes": 1048576,
        "imageDimensionsToken": "image_dimensions_token_from_original_files_api_upload_response"
      }
    ]
  }
}

Create response

The create endpoint returns a public task id. Poll the status endpoint until the task succeeds or fails.

{
  "id": "task_happyhorse_1_1_example",
  "status": "queued",
  "model": "happyhorse-1-1",
  "reserved_credits": 145,
  "final_credits": 0,
  "settlement_status": "RESERVED",
  "created_at": "2026-05-11T00:00:00.000Z",
  "updated_at": "2026-05-11T00:00:00.000Z",
  "result": null,
  "error": null
}

Common errors

validation_failed, insufficient_credits, idempotency_conflict, rate_limited, not_found

Some modes require Files API reference uploads.

HappyHorse 1.1 API Integration