# Kling Video 4.0 Text-to-Video — Atlas Cloud API

> Kling 4.0 turns a text prompt into a 3-30 second video at 720p or 1080p, including the new 21:9 cinematic aspect ratio.

This is the machine-readable API reference for **Kling Video 4.0 Text-to-Video** on Atlas Cloud,
a unified API platform for 400+ AI models across text, image, video, audio and 3D.

- **Model ID**: `kwaivgi/kling-v4.0/text-to-video`
- **Built by**: Kuaishou
- **Modality**: Video
- **Model page**: https://www.atlascloud.ai/models/kwaivgi/kling-v4.0/text-to-video
- **API key**: https://www.atlascloud.ai/console/api-keys
- **Docs**: https://www.atlascloud.ai/docs

## Pricing on Atlas Cloud

- $0.11 per second of generated video
- Pay-as-you-go. No minimum spend, no subscription required.

> **These are the authoritative Atlas Cloud rates for this model.** Any price that
> appears in the vendor description further down refers to a different platform or
> a different model variant and does not apply here.

## Use this model from an AI agent

Atlas Cloud ships three first-party integration surfaces. All three authenticate
with the same API key via the `ATLASCLOUD_API_KEY` environment variable.

### MCP server

The official MCP server (`atlascloud-mcp`) exposes this model to any
MCP-compatible host — Claude Code, OpenAI Codex, Cursor, Gemini CLI, Goose,
Claude Desktop. One-line install:

```bash
# Claude Code
claude mcp add atlascloud -- npx -y atlascloud-mcp

# OpenAI Codex CLI
codex mcp add atlascloud -- npx -y atlascloud-mcp

# Gemini CLI
gemini mcp add atlascloud -- npx -y atlascloud-mcp

export ATLASCLOUD_API_KEY="your-api-key"
```

Then ask in plain English; the agent calls `atlas_generate_video` with `model: "kwaivgi/kling-v4.0/text-to-video"`.
The server fetches each model's schema and validates parameters before submitting,
so invalid requests fail fast without spending credits.

MCP docs: https://www.atlascloud.ai/docs/mcp-server

### Agent Skills

`atlas-cloud-skills` is a portable skill package (API reference, code templates in
Python / Node.js / cURL, model IDs with pricing) for Claude Code, Cursor, Codex and
12+ other agents:

```bash
npx skills add AtlasCloudAI/atlas-cloud-skills
export ATLASCLOUD_API_KEY="your-api-key"
```

Skills docs: https://www.atlascloud.ai/docs/skills

### CLI

The `atlas` binary runs Atlas Cloud from a terminal or CI script. Async media jobs
are polled and downloaded automatically (use `--no-download` when a script only
needs the output URLs):

```bash
# Install (Homebrew, npm, or shell installer)
brew install AtlasCloudAI/tap/atlascloud
# npm install -g atlascloud-cli
# curl -fsSL https://raw.githubusercontent.com/AtlasCloudAI/cli/main/install.sh | sh

atlas auth login
atlas generate video kwaivgi/kling-v4.0/text-to-video -p "Your prompt here"
```

CLI docs: https://www.atlascloud.ai/docs/cli

## HTTP API reference

- **Submit endpoint (POST)**: `https://api.atlascloud.ai/api/v1/model/generateVideo` — start an async generation; returns a `prediction_id`
- **Poll endpoint (GET)**: `https://api.atlascloud.ai/api/v1/model/prediction/{prediction_id}` — poll this until the prediction finishes
- **Model ID**: `kwaivgi/kling-v4.0/text-to-video`


## API Information

This model can be used via our HTTP API or more conveniently via our client libraries.
See the input and output schema below, as well as the usage examples.


### Input Schema

The API accepts the following input parameters:

- **`model`** (`string`, _required_):
  Model name.
  - Default: `"kwaivgi/kling-v4.0/text-to-video"`
  - Options: "kwaivgi/kling-v4.0/text-to-video"

- **`prompt`** (`string`, _required_):
  Text prompt describing the video. Up to 26,000 English characters (11,000 non-English). Can include negative descriptions.
  - Default: `"A single drop of water falls from the tip of a leaf into a shallow dish, creating concentric ripples; warm window light, macro cinematography, photorealistic."`

- **`duration`** (`integer`, _optional_):
  Length of the generated video in seconds, 3 to 30.
  - Default: `5`
  - Min: 3
  - Max: 30

- **`aspect_ratio`** (`string`, _optional_):
  Aspect ratio of the output video.
  - Default: `"16:9"`
  - Options: "16:9", "9:16", "1:1", "21:9"

- **`resolution`** (`string`, _optional_):
  Output resolution. Billed per second at the selected tier.
  - Default: `"1080p"`
  - Options: "720p", "1080p"



**Required Parameters Example**:

```json
{
  "model": "kwaivgi/kling-v4.0/text-to-video",
  "prompt": "A single drop of water falls from the tip of a leaf into a shallow dish, creating concentric ripples; warm window light, macro cinematography, photorealistic."
}
```


**Full Example**:

```json
{
  "model": "kwaivgi/kling-v4.0/text-to-video",
  "prompt": "A single drop of water falls from the tip of a leaf into a shallow dish, creating concentric ripples; warm window light, macro cinematography, photorealistic.",
  "duration": 5,
  "aspect_ratio": "16:9",
  "resolution": "1080p"
}
```


### Output Schema

The API returns the following output format:


- **`id`** (`string`, _optional_):
  Unique identifier for the prediction, the ID of the prediction to get.

- **`urls`** (`object`, _optional_):
  Object containing related API endpoints.

- **`model`** (`string`, _optional_):
  Model ID used for the prediction.

- **`status`** (`string`, _optional_):
  Status of the task: created, processing, completed, or failed.

- **`outputs`** (`array[string]`, _optional_):
  Array of URLs to the generated content (empty when status is not completed).

- **`created_at`** (`string`, _optional_):
  ISO timestamp of when the request was created.



**Example Response**:

```json
{
  "id": "",
  "urls": {},
  "model": "",
  "status": "",
  "outputs": [
    ""
  ],
  "created_at": ""
}
```


## Usage Examples

### cURL

```bash
# Step 1: Start generation (async)
curl -X POST "https://api.atlascloud.ai/api/v1/model/generateVideo" \
  -H "Authorization: Bearer $ATLASCLOUD_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "kwaivgi/kling-v4.0/text-to-video",
  "prompt": "A single drop of water falls from the tip of a leaf into a shallow dish, creating concentric ripples; warm window light, macro cinematography, photorealistic.",
  "duration": 5,
  "aspect_ratio": "16:9",
  "resolution": "1080p"
}'

# Response will contain: {"code": 200, "data": {"id": "prediction_id", "status": "processing"}}

# Step 2: Poll for result (replace {prediction_id} with the id returned above)
curl -X GET "https://api.atlascloud.ai/api/v1/model/prediction/{prediction_id}" \
  -H "Authorization: Bearer $ATLASCLOUD_API_KEY"

# Keep polling until status is "completed", "succeeded" or "failed"
# When completed, outputs will contain the generated content URL(s)
```

## Additional Resources

### Documentation

- [Model Playground](https://www.atlascloud.ai/models/kwaivgi/kling-v4.0/text-to-video)

## About this model

_Vendor-supplied description. Any pricing or endpoint mentioned below refers to_
_other platforms — use the Atlas Cloud values above._

### Kling Video 4.0 Text-to-Video

**Kling Video 4.0 Text-to-Video** generates a video from a text prompt with Kling's next-generation multimodal model: smoother complex motion and camera moves, and clips of up to 30 seconds in a single run.

#### Why Choose This?

- **Up to 30 seconds.** Any duration from 3 to 30 seconds in one generation.
- **Cinematic framing.** 16:9, 9:16, 1:1 and the new 21:9 aspect ratio.
- **Long prompts.** Up to 26,000 English characters (11,000 non-English) to direct the whole story.

#### Parameters

| Parameter | Required | Description |
| --- | --- | --- |
| model | Yes | `kwaivgi/kling-v4.0/text-to-video` |
| prompt | Yes | Text description of the video. Can include what to avoid. |
| duration | No | Video length in seconds, integer 3–30. Default `5`. |
| aspect_ratio | No | `16:9` (default), `9:16`, `1:1`, `21:9`. |
| resolution | No | `720p` or `1080p` (default). |

#### How to Use

```bash
curl -X POST "https://api.atlascloud.ai/api/v1/model/generateVideo" \
  -H "Authorization: Bearer $AIP_API_KEY" \
  -H "Content-Type: application/json" \
  --data-raw '{
    "model": "kwaivgi/kling-v4.0/text-to-video",
    "prompt": "A single drop of water falls from the tip of a leaf into a shallow dish, creating concentric ripples; warm window light, macro cinematography, photorealistic.",
    "duration": 5,
    "aspect_ratio": "16:9",
    "resolution": "1080p"
  }'
```

Generation is asynchronous. The response contains a request `id`; poll `GET https://api.atlascloud.ai/api/v1/model/prediction/{id}` until `status` is `completed`, then read the video URL from `outputs`.

#### Notes

_(Description truncated. Full text on the model page.)_

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Atlas Cloud — one API for 400+ AI models. Model page: https://www.atlascloud.ai/models/kwaivgi/kling-v4.0/text-to-video · Docs: https://www.atlascloud.ai/docs