# Kling v2.1 i2v Master — Atlas Cloud API

> Delivers professional-grade image-to-video generation with precise motion continuity and visual depth.

This is the machine-readable API reference for **Kling v2.1 i2v Master** on Atlas Cloud,
a unified API platform for 400+ AI models across text, image, video, audio and 3D.

- **Model ID**: `kwaivgi/kling-v2.1-i2v-master`
- **Built by**: Kuaishou
- **Modality**: Video
- **Model page**: https://www.atlascloud.ai/models/kwaivgi/kling-v2.1-i2v-master
- **API key**: https://www.atlascloud.ai/console/api-keys
- **Docs**: https://www.atlascloud.ai/docs

## Pricing on Atlas Cloud

- $0.238 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-v2.1-i2v-master"`.
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-v2.1-i2v-master -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-v2.1-i2v-master`


## 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-v2.1-i2v-master"`

- **`prompt`** (`string`, _required_):
  Text prompt for generation; Positive text prompt; Cannot exceed 2500 characters.
  - Default: `"The scene opens with a small fishing boat caught in the midst of a raging storm. The sky is dark and ominous, filled with swirling clouds and flashes of lightning. The sea is tumultuous, with massive waves crashing against the boat, threatening to capsize it. The boat's deck is slick with rain, and the crew members are struggling to maintain control."`

- **`negative_prompt`** (`string`, _optional_):
  Negative text prompt; Cannot exceed 2500 characters.
  - Default: `"blur, distort, and low quality"`

- **`image`** (`string`, _required_):
  First frame of the video; Supported image formats include.jpg/.jpeg/.png; The image file size cannot exceed 10MB, and the image resolution should not be less than 300*300px.
  - Default: `"https://static.atlascloud.ai/media/images/1749522950129341275_kHvrnkgd.jpeg"`

- **`guidance_scale`** (`number`, _optional_):
  The guidance scale to use for the generation.
  - Default: `0.5`
  - Min: 0
  - Max: 1

- **`duration`** (`string`, _optional_):
  The duration of the generated media in seconds.
  - Default: `"5"`
  - Options: "5", "10"



**Required Parameters Example**:

```json
{
  "model": "kwaivgi/kling-v2.1-i2v-master",
  "prompt": "The scene opens with a small fishing boat caught in the midst of a raging storm. The sky is dark and ominous, filled with swirling clouds and flashes of lightning. The sea is tumultuous, with massive waves crashing against the boat, threatening to capsize it. The boat's deck is slick with rain, and the crew members are struggling to maintain control.",
  "image": "https://static.atlascloud.ai/media/images/1749522950129341275_kHvrnkgd.jpeg"
}
```


**Full Example**:

```json
{
  "model": "kwaivgi/kling-v2.1-i2v-master",
  "prompt": "The scene opens with a small fishing boat caught in the midst of a raging storm. The sky is dark and ominous, filled with swirling clouds and flashes of lightning. The sea is tumultuous, with massive waves crashing against the boat, threatening to capsize it. The boat's deck is slick with rain, and the crew members are struggling to maintain control.",
  "negative_prompt": "blur, distort, and low quality",
  "image": "https://static.atlascloud.ai/media/images/1749522950129341275_kHvrnkgd.jpeg",
  "guidance_scale": 0.5,
  "duration": "5"
}
```


### 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 (e.g., “2023-04-01T12:34:56.789Z”).

- **`has_nsfw_contents`** (`array[boolean]`, _optional_):
  Array of boolean values indicating NSFW detection for each output.



**Example Response**:

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


## 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-v2.1-i2v-master",
  "prompt": "The scene opens with a small fishing boat caught in the midst of a raging storm. The sky is dark and ominous, filled with swirling clouds and flashes of lightning. The sea is tumultuous, with massive waves crashing against the boat, threatening to capsize it. The boat's deck is slick with rain, and the crew members are struggling to maintain control.",
  "negative_prompt": "blur, distort, and low quality",
  "image": "https://static.atlascloud.ai/media/images/1749522950129341275_kHvrnkgd.jpeg",
  "guidance_scale": 0.5,
  "duration": "5"
}'

# 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-v2.1-i2v-master)

## About this model

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

### Kling 2.1

**Kling 2.1** is Kuaishou's advanced image-to-video generation model released in 2025. Designed for high-fidelity cinematic output, Kling 2.1 transforms reference images — with optional text prompts — into visually rich, lifelike video clips.

#### 🔧 Key Technology

- **3D Spatiotemporal Attention Architecture**  

  Enables realistic motion and coherent visual progression across frames.

- **Real-World Physics Simulation**  

  Produces natural, fluid, and intricate character movements and scene dynamics.

#### 🎬 Core Features

- **Image-to-Video Transformation**  

  Generates cinematic sequences from static images, optionally guided by user text.

- **AI-Assisted Prompting**  

  Offers intelligent prompt suggestions to help users craft effective input instructions.

- **Multiple Video Variants**  

  Capable of producing diverse outputs from the same prompt for greater creative flexibility.

#### 🚀 Performance

Kling 2.1 marks a major leap over Kling 2.0 in:

- **Visual Realism**

- **Motion Coherence**

- **Prompt Adherence**

In comparative evaluations, it rivals the quality of top-tier closed-source video generation models.

---

**Kling 2.1** sets a new benchmark for generative video, blending artistry, physics, and AI precision.

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Atlas Cloud — one API for 400+ AI models. Model page: https://www.atlascloud.ai/models/kwaivgi/kling-v2.1-i2v-master · Docs: https://www.atlascloud.ai/docs