HappyHorse 1.0 API

Unifically: one endpoint, one API key, USD billing.

What is HappyHorse 1.0?

HappyHorse 1.0 is a video generation model that produces video and matching audio in a single pass. The same endpoint covers three input modes: text-to-video for prompt-only generation, image-to-video that animates a first-frame image, and reference-to-video that takes 1 to 9 character images and locks them into the clip via characterN tags in the prompt. Output runs at 720p or 1080p across five aspect ratios (16:9, 9:16, 1:1, 4:3, 3:4) with clip lengths from 3 to 15 seconds. Because audio and video come back from the same render, sound and on-screen action stay in sync without a separate audio pipeline.

Key features of HappyHorse 1.0

Five features cover how HappyHorse 1.0 fits into a production pipeline.

Joint audio and video in one pass

The model generates the picture and the soundtrack together, so dialogue, footsteps, ambient noise, and on-screen events stay locked. No second TTS or foley pass, no manual lip sync, no drift between two pipelines.

Three input modes on one endpoint

Text-to-video for fresh briefs. Image-to-video for animating a still. Reference-to-video for character continuity. Switch by setting the `mode` field; everything else stays the same.

Up to nine reference images for character work

Reference-to-video takes 1 to 9 images. Refer to each in the prompt as `character1`, `character2`, and so on, and the model holds identity, costume, and silhouette across the clip.

Five aspect ratios and 720p or 1080p output

16:9, 9:16, 1:1, 4:3, and 3:4 cover horizontal hero, vertical social, square feed, and the older broadcast ratios in one model. Choose 720p for fast drafts or 1080p for delivery.

3 to 15 second clips with seed control

Clip length is a single integer field. Pair it with an integer seed (0 to 2,147,483,647) to get the same render back across re-runs. Useful for A/B prompts and locking a clip you want to keep.

Best for

Ads and marketing with native audio

Cinematic clips from text or product images that come back with matching audio in the same render. No second pass for voice or foley.

E-commerce hero shots

Animate a product still with image-to-video. The first frame anchors the look while the prompt drives the camera move and ambient sound.

Short-form drama and serialized clips

Reference-to-video keeps a character consistent across scenes. Use `character1`, `character2` tags in the prompt to lock identity over a sequence.

Social campaigns with multiple ratios

Five aspect ratios in one model means a 16:9 cut, a 9:16 cut, and a 1:1 cut all come from the same prompt without re-prompting per platform.

Brand-aligned reference work

Up to nine references per call lets you carry brand colours, costume, and product geometry across an entire campaign without retraining a custom model.

Quick turnaround dialogue scenes

Joint audio means a clip with spoken lines or beat-driven cuts works in one shot. Useful when audio sync is the part that has historically slowed a render.

Use cases

Build a product hero in one call by passing the packaging shot as first_frame_url and a 5-second camera-move prompt; the result lands at 1080p with matching ambient audio. Make a vertical TikTok cut by switching ratio to 9:16 and re-running the same prompt. Run a serialized story by uploading 2 or 3 character references and writing prompts that mention character1 and character2 directly, so the cast stays consistent across scenes. Lock a winning result with a seed and an integer between 0 and 2,147,483,647 so you can re-render at a different duration without losing the look.

API examples

Call HappyHorse 1.0 from any language by POSTing to /v1/tasks. Full parameter docs live at docs.unifically.com/models/video/alibaba/happyhorse-1.0-video.

curl -X POST https://api.unifically.com/v1/tasks \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "alibaba/happyhorse-1.0-video",
    "input": {
      "mode": "t2v",
      "prompt": "A golden retriever running through a field of wildflowers at sunset",
      "resolution": "1080P",
      "ratio": "16:9",
      "duration": 5
    }
  }'

Successful submission returns a task_id. Poll GET /v1/tasks/<task_id> or set a callback_url on the request to receive the finished video URL.

FAQs