Kling O3 Standard Reference to Video is Kling'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, the kling family rule its prompt enhancer applies. Where a line is general craft advice rather than a documented fact about Kling O3 Standard Reference to Video, the page says so.
What Kling O3 Standard 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 |
|---|---|---|
prompt | Required unless `multi_prompt` provided | string (max 2500) |
image_urls | Reference subject images (optional, max 4 combined with elements). fal field is `image_urls`. | array |
duration | 3-15 seconds (string enum) | string (min 3, max 15)default: 5 |
aspect_ratio | Aspect ratio | 16:9 · 9:16 · 1:1default: 16:9 |
generate_audio | O3 default false | booleandefault: false |
- — Verified against fal.ai/models/fal-ai/kling-video/o3/pro/reference-to-video — `negative_prompt` not in docs; `elements`, `start_image_url`, `end_image_url`, `multi_prompt` not yet modeled
The rule Versely's enhancer applies
Versely's prompt enhancer carries a per-family rule for kling models, applied automatically whenever it rewrites a prompt for Kling O3 Standard Reference to Video. Verbatim:
“Kling video models work best with clear scene descriptions including camera movement (pan, zoom, tracking shot), subject action, and environment details. Specify motion direction and pacing.”
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.
- The family MODEL_TIPS rules the prompt enhancer applies still fire here, because they match on the model name substring: a Kling O3 reference job gets the Kling tip ('clear scene descriptions including camera movement (pan, zoom, tracking shot), subject action, and environment details... motion direction and pacing'), VEO 3.1 Reference to Video gets the VEO tip ('camera angles, movement types (dolly, crane, steadicam), lighting setup, and temporal flow'), Seedance gets 'motion-focused descriptions... movement patterns, choreography, and dynamic visual elements', and Wan gets 'straightforward scene descriptions and style keywords'. Write the prompt in the register the family tip already rewards; spend the references on identity.
- Audio defaults diverge quietly: Kling O3's generate_audio description says 'O3 default false', while VEO 3.1 and Seedance expose generate_audio as a normal toggle. If a reference-to-video clip comes back silent on Kling O3, that's the documented default, not a failure.
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.
[SUBJECT — plain-language description matching your reference images] [ACTION] in [ENVIRONMENT]. Camera: [pan / zoom / tracking shot], moving [DIRECTION] at [PACING].
Use when: Kling O3 Standard Reference to Video — no token syntax in the schema; the Kling family tip asks for named camera movement, subject action, environment detail, and explicit motion direction and pacing. Remember generate_audio defaults to false on O3.
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 Kling O3 Standard 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, including the kling rule quoted on this page, 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
- 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.
- Sending more references than the schema takes: 4th image to VEO 3.1 (cap 3), 5th to Kling O3 (cap 4 combined with elements), 13th file to Seedance (total cap 12 across images, videos, and audio), 6th image to Wan 2.7 (5 per array).
- Treating a silent Kling O3 result as a bug — generate_audio's documented O3 default is false, so audio has to be switched on explicitly.
The long-form guide
This page is the structured reference. For the essay treatment — worked examples, failure modes, and narrative — read Kling O3 Prompting: Camera, Motion, and Reasoning.
Frequently asked questions
How long can a Kling O3 Standard Reference to Video prompt be?+
Kling O3 Standard 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 Kling O3 Standard Reference to Video support negative prompts?+
No — Kling O3 Standard 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 Kling O3 Standard Reference to Video support?+
The aspect_ratio parameter is an enum: 16:9, 9:16, 1:1. Set the parameter — describing the frame shape in prose does nothing on its own.
How long can a Kling O3 Standard Reference to Video generation be?+
Duration is bounded (min 3, max 15). Write one continuous beat sized to that window rather than a multi-act script.
How does the Versely agent know Kling O3 Standard 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; separately, the prompt enhancer applies the kling family rule quoted on this page to the prompt text itself. Nothing on this page is guessed — it is the same schema surface those tools read.
Related prompting guides
Generate with Kling O3 Standard Reference to Video
Kling O3 Standard 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.