curl-X POST 'https://pollo.ai/api/platform/v1/generation/kling-ai/kling-v4/video'\-H'Content-Type: application/json'\-H'x-api-key: YOUR_API_KEY'\-d'{ "input": { "prompt": "A cinematic shot of a golden retriever running through a field of sunflowers at sunset, warm rim light, shallow depth of field", "aspectRatio": "16:9", "duration": 10, "resolution": "1080p" }}'
Optionally include webhookUrl to receive a callback when the task succeeds or fails.
Optional request field
{"input":{"prompt":"A cinematic shot of a golden retriever running through a field of sunflowers at sunset, warm rim light, shallow depth of field","aspectRatio":"16:9","duration":10,"resolution":"1080p"},"webhookUrl":"https://example.com/webhooks/pollo"}
Schema
Input fields for the selected endpoint and mode.
Field
Type
Required
Description
prompt
string
Yes
Text prompt describing the content to generate.
aspectRatio
string
No
Output aspect ratio, as width:height (e.g. 16:9).
duration
integer
No
The duration of the generated video, in seconds.
resolution
string
No
Output resolution of the generated media (e.g. 720p, 1080p, 2K, 4K). Values are case-insensitive.
Kling 4.0 gives video creators control over how a scene unfolds, combining multiple keyframes, mixed-media references, and coordinated camera movement with native audiovisual generation.
Run Kling 4.0 on Pollo API to bring directed video generation into creative applications, storyboard tools, and workflows that turn existing assets into new scenes.
Key Features of Kling 4.0 API
Multiple Keyframe Control
Define important visual moments throughout a sequence, including character poses, scene changes, and final compositions. Keyframes guide the progression between those moments.
Omni Reference Guidance
Combine image, video, subject, and voice references to guide appearance, movement, and sound. Different assets can contribute distinct creative instructions within the same generation.
Complex Motion and Camera Direction
Direct tracking shots, orbits, and continuous action with greater motion stability. Subjects and camera movements can develop together through demanding scenes and changing compositions.
Native Stereo Audio
Generate visuals with stereo sound and synchronized speech. Dialogue, vocal performance, and surrounding audio help establish a scene’s atmosphere alongside the visible action.
Longer Narrative Development
Give a scene room for setup, interaction, and resolution within one generation. Longer takes support gradual reactions, connected actions, and more deliberate narrative pacing.
Use Cases of Kling 4.0 API
Storyboard Animation: Use keyframe images to guide a character’s entrance, turning point, and closing composition.
Character-Based Series: Reuse subject references to guide recognizable appearances across separately generated scenes.
Sports Sequence Prototypes: Explore continuous movement, tracking cameras, and changes in viewpoint before planning a physical shoot.
Creative Adaptation: Reference an existing clip’s pacing and camera work while introducing different subjects or products.
Dialogue Scene Development: Combine spoken lines, character reactions, and ambient sound when prototyping short dramatic exchanges.
Campaign Scene Revisions: Produce alternate backgrounds, gestures, or expressions from existing footage for creative review.
Stylized Animation: Pair visual references with ordered story beats to develop felt, pixel-art, or animated sequences.
How to Use Kling 4.0 on Pollo API
Get an API Key: Create a Pollo API account and generate your API key from the developer dashboard.
Choose the Model: Send requests to the Kling 4.0 video endpoint at /generation/kling-ai/kling-v4/video.
Add Your Inputs: Enter your text prompt and include reference assets or keyframe guidance where supported. Follow the endpoint’s request schema to configure available generation settings.
Generate and Retrieve: Submit the task, poll the returned task status, and download the finished video once processing succeeds.
Prompting Best Practices for Kling 4.0 API
Describe the scene as a sequence of observable events. Explain what each reference contributes, how the camera moves, and which visual details should persist.
A Simple Prompt Formula
Reference roles + subject and setting + ordered actions + camera movement + key visual moments + dialogue and sound + continuity requirements
What You Should Notice
Reference Roles: Distinguish assets that guide identity, appearance, movement, or style.
Visual Milestones: Establish the opening, important changes, and intended ending before adding smaller details.
Movement Between Frames: Explain how the subject travels or changes between key visual states.
Camera Intent: Specify whether the camera follows the subject, stays fixed, or changes position.
Audio Direction: Attribute dialogue to individual speakers and describe the surrounding sound.
Editing Boundaries: For revisions, identify both the requested change and the details to preserve.
Example Prompts
Storyboard-Guided Mystery Scene
“Use the supplied keyframes as visual milestones. A museum caretaker notices muddy footprints, follows them past a display cabinet, and discovers a tiny mechanical bird beneath a bench. Connect the moments with slow tracking movement. Preserve the caretaker’s green uniform and the gallery’s warm evening lighting.”
Continuous Sports Action
“A skateboarder approaches a shallow concrete bowl, drops in, carves around its curved wall, and rolls toward the exit. The camera tracks alongside at waist height without cutting. Keep the board and clothing consistent throughout. Include wheel rumble, a brief scrape, and distant park ambience.”
Reference-Guided Felt Animation
“Use the character image for the felt rabbit’s appearance and the workshop image for the setting. The rabbit sorts oversized buttons, discovers one glowing blue button, and holds it toward the window. Preserve visible fabric fibers. Use gentle stop-motion movement and soft wooden percussion.”
Targeted Scene Revision
“In the supplied greenhouse clip, change the gardener’s expression from concern to relief when the seedling opens its first leaf. Preserve the gardener’s identity, clothing, hand placement, camera movement, and background. Keep the watering-can sound and surrounding ambience. Make the expression change gradual.”
Kling 4.0 vs Kling 3.0 vs Veo 3.1
Capability
Kling 4.0
Kling 3.0
Veo 3.1
Visual timing control
Multiple keyframes throughout a sequence
Start and end frames; multi-shot direction
First and last frame guidance
Reference guidance
Images, videos, subjects, and voice styles
Reference capabilities vary across standard and Omni workflows
Asset-image references
Native sound
Stereo audio with synchronized speech
Native audio with single-channel output
Native sound generation
Story structure
Longer takes with intermediate visual milestones
Compact multi-shot sequences
Short audiovisual clips with extension support
Recommended For
Scenes requiring reference control and planned visual progression
Short sequences within an established Kling workflow
Image-guided clips with generated sound
Why Choose Kling 4.0 API?
Choose Kling 4.0 when a scene needs specific visual milestones, recognizable subjects, and coordinated movement. Its references and keyframes address different parts of that creative direction.
Pollo API provides access to 300+ image and video models, helping teams explore alternative outputs through a shared platform with centralized documentation.
Explore Kling 4.0 for storyboard-driven generation, reference-based scenes, and targeted revisions, then build the supported capabilities into your application using Pollo’s developer documentation.
Kling 4.0 API FAQs
What is Kling 4.0?
Kling 4.0 is Kling AI’s multimodal video model. It combines generation and editing with reference guidance, multiple keyframes, complex motion handling, and synchronized audiovisual output.
Can Kling 4.0 generate videos from text and images?
Yes. The model supports text-led and image-guided generation, alongside broader reference workflows. Pollo’s endpoint schema determines which inputs are available through this integration.
How do keyframes help control Kling 4.0 videos?
Keyframes establish visual states at important points in a sequence. They help direct poses, compositions, and scene changes, while the prompt describes the movement connecting them.
Does Kling 4.0 generate audio with video?
Yes. Kling 4.0 supports native stereo audio and synchronized speech. Specify speakers, dialogue, delivery, and ambient sound to give the model clearer audiovisual direction.
When should I choose Kling 4.0 over Kling 3.0?
Choose Kling 4.0 when intermediate keyframes, broader reference combinations, stereo audio, or longer narrative development matter. Kling 3.0 remains an option for shorter multi-shot sequences.
Why run Kling 4.0 through Pollo API?
Pollo API gives one integration for Kling 4.0 and 300+ other image and video models, with clear documentation and task tracking.
