Happy Horse 1.0 Reference to Video is Alibaba's reference-to-video model on Versely. This page is its structured prompting reference: the 5 parameters its schema actually exposes, the reference-to-video technique that applies to it, copy-ready templates.
Everything here is grounded in the same sources Versely's agent reads — the model's input schema. Where a line is general craft advice rather than a documented fact about Happy Horse 1.0 Reference to Video, the page says so.
What Happy Horse 1.0 Reference to Video wants
The exact input surface, from the same schema the Versely agent fetches with get_model_input_schema before every generation.
| Parameter | What it does | Values |
|---|---|---|
promptreq | Text prompt (max 2500 chars; reference subjects via character1..character9) | string (max 2500) |
image_urlsreq | 1-9 reference images | array (min 1, max 9) |
duration | Seconds (integer enum 3-15) | 3 · 4 · 5 · 6 · 7 · 8 · 9 · 10 · 11 · 12 · 13 · 14 · 15default: 5 |
aspect_ratio | Aspect ratio | 16:9 · 9:16 · 1:1 · 4:3 · 3:4default: 16:9 |
resolution | Resolution | 720p · 1080pdefault: 1080p |
- — Verified against fal OpenAPI — no negative_prompt; resolution is 720p/1080p only
Technique that applies here
Reference-images-to-video: multi-image identity/style consistency
- Reference-to-video models take a prompt PLUS a set of reference images (sometimes videos and audio too), and the single most model-specific thing in this family is HOW each schema wants you to point at those references from inside the prompt text. Happy Horse 1.0's prompt description says to reference subjects via character1..character9 — positional tokens matched to the order of the 1-9 required image_urls. Seedance 2.0 Fast's prompt description says to reference assets via @Image1, @Video1, @Audio1 — typed, numbered tokens spanning all three reference arrays. VEO 3.1, Kling O3, and Wan 2.7 define no token syntax at all in their schemas — on those, describe the subject in plain language and let the references carry identity.
- Reference caps are hard schema limits, not suggestions, and they differ by an order of magnitude across the family: VEO 3.1's image_urls tops out at 3 reference images, Kling O3 Standard's at 4 (combined with elements), Happy Horse and Seedance take up to 9 images, Seedance adds up to 3 videos (combined 2-15s, under 50MB total, 480p-720p) and 3 audios (combined ≤15s) with a total of 12 reference files across modalities, and Wan 2.7 caps reference_image and reference_video at 5 each. Budget your identity, style, and product references to the model you're actually calling.
- Only some of these schemas expose a negative_prompt. VEO 3.1's variant has one ('Exclusions'), and Wan 2.7 gives you 500 characters of negative_prompt next to a 5,000-character main prompt. Happy Horse's schema notes are explicit the other way: 'no negative_prompt' — verified against the fal OpenAPI. On models without the field, exclusions have to be phrased positively in the main prompt or dropped.
Copy-ready templates
Replace the bracketed slots; each template says when it's the right shape.
character1 [ACTION — what the person/subject from image 1 does] while character2 [ROLE OF SECOND REFERENCE — e.g. 'stands beside them holding the product']. Setting: [ENVIRONMENT]. [ONE CAMERA OR MOOD SENTENCE].
Use when: Happy Horse 1.0 Reference to Video — its prompt schema defines character1..character9 tokens mapped to the order of your 1-9 image_urls, with up to 2,500 characters to work with.
@Image1 [SUBJECT ROLE — e.g. 'the presenter'] [ACTION], styled to match @Image2. Motion: [MOVEMENT PATTERN / CHOREOGRAPHY — what moves and how]. [Optional: sync the cut to @Audio1 / continue the motion of @Video1.]
Use when: Seedance 2.0 Fast Reference to Video — the schema's own token syntax is @Image1/@Video1/@Audio1 across its three reference arrays, and the Seedance family tip rewards motion-focused, choreography-first description.
How the Versely agent does this automatically
You can use this page by hand, or let the agent apply the same knowledge. Four real mechanisms — no more, no less:
get_model_input_schema— before generating, the agent looks up Happy Horse 1.0 Reference to Video's exact input fields, required fields, allowed values, defaults, and min/max bounds. The parameter table above is that same surface.- The prompt enhancer's family rules — 12 per-family rewrite rules (this model's family isn't one of the 12, so only general enhancement applies) shape how a rough prompt gets rewritten.
- The per-provider speech guide — for TTS scripts, the agent follows a provider-specific tag scheme — not relevant to this model, but it's why voiceover scripts come out marked up correctly.
expand_movie_scene— in movie flows, brief scene ideas are rewritten into detailed cinematic descriptions before generation.
Mistakes that waste generations
- Pointing at references with prose ('the woman from the second photo') on a model whose schema defines a token syntax. Happy Horse wants character1..character9 and Seedance wants @Image1/@Video1/@Audio1 — the tokens are part of the input contract, not a stylistic choice.
- Using one model's token syntax on another. @Image1 means nothing to Happy Horse, and character1 means nothing to Seedance — and neither means anything to VEO, Kling O3, or Wan, whose schemas define no reference tokens at all.
- Writing 'no text, no watermark, no extra people' into the MAIN prompt on VEO or Wan, which both expose a dedicated negative_prompt field — or conversely, expecting a negative_prompt to exist on Happy Horse, whose schema notes explicitly say it has none.
Frequently asked questions
How long can a Happy Horse 1.0 Reference to Video prompt be?+
Happy Horse 1.0 Reference to Video's schema caps the prompt at 2,500 characters. Spend them on the subject, motion, and the register its family rewards rather than restating parameters the schema already controls.
Does Happy Horse 1.0 Reference to Video support negative prompts?+
No — Happy Horse 1.0 Reference to Video's published schema has no negative_prompt parameter. Exclusions have to be phrased positively inside the main prompt, or dropped.
Which aspect ratios does Happy Horse 1.0 Reference to Video support?+
The aspect_ratio parameter is an enum: 16:9, 9:16, 1:1, 4:3, 3:4. Set the parameter — describing the frame shape in prose does nothing on its own.
How long can a Happy Horse 1.0 Reference to Video generation be?+
Duration is a hard enum: 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15. Write one continuous beat sized to the window you pick, not a script the model will compress.
How does the Versely agent know Happy Horse 1.0 Reference to Video's parameters?+
Before generating, the agent calls its get_model_input_schema tool, which looks up the exact input fields, required fields, allowed values, defaults, and min/max bounds for the model. Nothing on this page is guessed — it is the same schema surface those tools read.
Related prompting guides
Generate with Happy Horse 1.0 Reference to Video
Happy Horse 1.0 Reference to Video is live in Versely — paste a template above, or just describe what you want and let the agent map it onto the schema for you.