# Kling v2.1 | Master | Text to Video

Kling 2.1 Master A premium text-to-video model that delivers smooth motion, cinematic visuals, and highly accurate prompt results for top-quality video generation.

## API Information

- **Model Slug:** kling-v2-1-master-text-to-video
- **Branded URL:** https://www.eachlabs.ai/kling/kling-v2-1/kling-v2-1-master-text-to-video
- **Provider:** Kling
- **Category:** Text to Video
- **Output Type:** video
- **Status:** active
- **Version:** 0.0.1
- **Base Cost:** A 5-second video costs $1.40. Each additional second costs $0.28.
- **Estimated Processing Time:** 180 seconds
- **Last Updated:** 2026-06-17
- **Interactive Demo:** https://www.eachlabs.ai/ai-models/kling-v2-1-master-text-to-video

## Pricing

- **Charge Type:** dynamic
- **Pricing Details:** A 5-second video costs $1.40. Each additional second costs $0.28.

### Pricing Rules

| Condition | Pricing |
| --- | --- |
| Rule 1 | A 5-second video costs $1.40. Each additional second costs $0.28. |

## Input Schema

| Parameter | Type | Required | Default | Constraints | Description |
|-----------|------|----------|---------|-------------|-------------|
| prompt | string | Yes | - | - | - |
| duration | integer | Yes | 5 | 5,10 | - |
| aspect_ratio | string | No | 16:9 | 16:9,9:16,1:1 | - |
| negative_prompt | string | No | - | - | - |
| cfg_scale | number | No | 0.5 | 0–1 | - |

## Example Request

```bash
curl -X POST https://api.eachlabs.ai/v1/prediction/ \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "kling-v2-1-master-text-to-video",
  "input": {
    "duration": 5,
    "prompt": "Golden sunlight spills into the quiet bookshop, illuminating dust motes that drift like delicate fireflies through the warm air; the soft flutter of turning pages, paired with the distant hiss of a steaming espresso machine, forms a gentle counterpoint to the murmured conversations, capturing the soul of this serene literary haven."
  }
}'
```

## Output Schema

Response returned by `GET /v1/prediction/{id}` when the job completes:

```json
{
  "status": "success",
  "predictionID": "string",
  "output": "string (URL of generated video)",
  "metrics": {
    "predict_time": "number (seconds)"
  }
}
```

## Polling

```bash
curl https://api.eachlabs.ai/v1/prediction/{PREDICTION_ID} \
  -H "Authorization: Bearer YOUR_API_KEY"
```

| Status | Meaning |
|--------|---------|
| `processing` | Still running — poll again |
| `success` | Done — read `output` |
| `error` | Failed — read `message` / `details` |

## Webhook (alternative to polling)

Pass `"webhook_url": "https://your.host/path"` in the create request. Eachlabs POSTs this payload when the job ends:

```json
{
  "exec_id": "prediction-uuid",
  "status": "succeeded",
  "output": "https://...",
  "error": ""
}
```

`status` is `"succeeded"` or `"failed"`. `exec_id` equals the `predictionID` from create. Return 2xx within 30 seconds.

## Errors

Error body: `{ "status": "error", "message": "...", "details": "..." }`

| Code | Meaning |
|------|---------|
| `400` | Invalid input |
| `401` | Missing / invalid `Authorization` bearer token |
| `404` | Unknown model or prediction id |
| `429` | Rate limit — 100 creates / min, 10 concurrent per key |
| `5xx` | Retry with backoff |

## Overview

**kling-v2-1-master-text-to-video — Text to Video AI Model**

Developed by Kling as part of the **kling-v2.1** family, **kling-v2-1-master-text-to-video** is a premium text-to-video AI model that transforms detailed text prompts into cinematic videos with smooth motion, realistic physics, and synchronized sound effects. This Kling text-to-video powerhouse solves the challenge of creating high-quality, professional-grade videos without expensive production teams, delivering up to 1080p resolution at 30fps for durations of 5-10 seconds or more. Ideal for creators seeking a **text-to-video AI model** with advanced simulation, it excels in generating lifelike animations from simple descriptions, making it a top choice for **Kling text-to-video** applications.

## Usage Notes

- API Base URL: `https://api.eachlabs.ai/v1`
- Authentication: send `Authorization: Bearer YOUR_API_KEY`. Generate a key from the Eachlabs dashboard at https://www.eachlabs.ai/dashboard/api-keys.
- File-typed parameters (`*_url`, `image_url`, `video_url`, `audio_url`, etc.) accept publicly-reachable HTTPS URLs only. Upload your asset first (GCS / S3 / your CDN) and pass the resulting URL. Data-URIs and localhost URLs are rejected.
- For structured parameters (arrays / objects) send real JSON values, not stringified payloads.
- Monetary values are reported in USD; per-token / per-megapixel rates may be billed in micro-cents internally.
- Prefer `webhook_url` over polling for long-running predictions — see the Webhook Callback section.