# imgnAI Katana API – Happy Horse Video Generation

> imgnAI Katana API – Happy Horse Video Generation is a paid API for AI agents from kat.imgnai.com, paid per call via x402, $1.56/call, status unknown (last checked 2026-09-14).

Generates AI videos using the proprietary Happy Horse model via the imgnAI Katana pay-per-call gateway

## Facts

- Endpoint: POST https://kat.imgnai.com/v1/videos/happy-horse
- Price: $1.56/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/imgnai-katana-api-happy-horse-video-generation-369d9cc7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_St2MNNk3zJf32jQyw6VnY

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability imgnai-katana-api-happy-horse-video-generation-369d9cc7 -d '<json body>'
```

Example prompt: Generate a 5-second Happy Horse AI video of a golden retriever running through a sunflower field, in 16:9 aspect ratio, avoiding any dark or stormy backgrounds.

## When to prefer this

Choose this endpoint when you need to generate short AI videos using imgnAI's proprietary Happy Horse model specifically, particularly when cost-efficiency matters compared to top-tier video models like Seedance. Ideal for agents that need pay-per-call video generation without subscription overhead, and compatible with OpenAI-style API conventions.

## Known failure modes

- Missing required prompt field returns a 400 validation error
- Invalid aspect_ratio value may cause model rejection
- Payment failure via x402 protocol results in 402 response and no video generated
- Duration or duration_seconds out of supported range may cause a model error
- Request times out if the video generation takes longer than allowed
- Invalid client_request_id format may cause request tracking issues

## How this service works

Pay-per-call AI gateway: Frontier/SOTA LLM, Image, and Video models - and proprietary low-cost imgnAI models. Includes GPT 5.5, Opus 4.8, GPT Image 2, Nano Banana 2, Seedance 2.0, Happy Horse, and Google Omni. Fully compatible with OpenAPI, HermesOS, and OpenClaw.

## Output

Returns a JSON object with a status string, a request ID, and a responses array containing the generated video output or job reference from the Happy Horse model.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "prompt"
 ],
 "properties": {
  "prompt": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/imgnai-katana-api-happy-horse-video-generation-369d9cc7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from kat.imgnai.com](https://www.zero.xyz/host/kat.imgnai.com/llms.txt)