Use HappyHorse 1.0 through Rivya Public API v1 with model id happyhorse-1-0, 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-1-0

Inputs

text, file

Files API

Required for reference modes

Base credits

per_output_second · 720p=28 · 1080p=48 · ⌈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-1-0	Use the happyhorse-1-0 API model id.
prompt	string	Yes	-	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	Resolution
aspect_ratio	select	No	16:9	-	16:9, 9:16, 1:1, 4:3, 3:4	Aspect ratio
duration	number	No	5	min 3 / max 15	-	Duration
seed	number	No	0	min 0 / max 2147483647	-	Leave it empty for a new random result each time. Reusing the same integer makes it easier to reproduce or fine-tune a previous result. It stays closer only when the prompt and other key settings also remain similar, and it is not a guaranteed 1:1 match.

Upload policy

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

Reference rule

Reference media: Use exactly 1 image for image-to-video or 2 to 9 images for reference video. Images must be JPEG, PNG, or WebP and no larger than 10 MB; single-image mode requires both dimensions to be at least 300 px, while reference mode requires the shortest side to be at least 400 px.

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	10 MB	image/jpeg, image/png, image/webp

Minimal request

{
  "model": "happyhorse-1-0",
  "prompt": "A cinematic product reveal with smooth camera movement",
  "params": {
    "resolution": "1080p",
    "aspect_ratio": "16:9",
    "duration": 5,
    "seed": 0
  }
}

Reference-file request

{
  "model": "happyhorse-1-0",
  "prompt": "A cinematic product reveal with smooth camera movement",
  "params": {
    "resolution": "1080p",
    "aspect_ratio": "16:9",
    "duration": 5,
    "seed": 0,
    "referenceMediaItems": [
      {
        "url": "https://cdn.example.com/reference-image.png",
        "kind": "image",
        "name": "reference-image.png",
        "mimeType": "image/png"
      }
    ]
  }
}

Create response

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

{
  "id": "task_happyhorse_1_0_example",
  "status": "queued",
  "model": "happyhorse-1-0",
  "reserved_credits": 28,
  "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 1.0 API Integration