# Kling 3.0

> Kling 3.0 by Kuaishou: 3 to 15 second clips in 720p, 1080p and 4K, from a description or the first and last frame, with optional sound.

Kling 3.0 is a Kuaishou video model. It makes 3 to 15 second clips from a description or from a photo — the first and, optionally, the last frame.

Quality: Standard (720p), Pro (1080p) or 4K. Sound is optional: effects, music and voices are made together with the picture; with sound costs more (same price in 4K). You pay per second of the clip.

One model, `kling-3.0` · ~4 min. The result follows the `input` fields (prompt, frames, references, `video_mode`, duration) — there are no separate «animate / edit» endpoints.



## Features

- `generate_audio` — audio in the clip

## Price

| Resolution | No sound, per second | With sound, per second |
|---|---|---|
| 720p | $0.088 | $0.132 |
| 1080p | $0.117 | $0.175 |
| 4k | $0.558 | $0.558 |

- Price = per-second price × clip length, rounded up to $0.001. Charged when the task is created and fully refunded if it fails.
- `generate_audio` defaults to `false`. In 4K the price is the same with or without sound.



## Parameters (field `input`)

| Parameter | Description | Values (default in bold) |
|---|---|---|
| `prompt` | What happens in the clip: scene, motion, camera, light, style | text, up to 2500 chars |
| `first_frame_url` | First frame: a photo link (https); the video starts from it | `"https://…"` |
| `last_frame_url` | Last frame (optional, only together with the first one) | `"https://…"` |
| `resolution` | Quality = the Kling mode: `720p` — Standard (std), `1080p` — Pro (pro), `4k` — 4K. You can also send `mode`: `std` / `pro` / `4k` | **`720p`** · `1080p` · `4k` |
| `aspect_ratio` | Aspect ratio | **`16:9`** · `9:16` · `1:1` |
| `duration` | Clip length in seconds | 3 to 15 (default **`5`**) |
| `generate_audio` | Sound in the clip (effects, music, voices). Default `false`; with sound costs more — see the price | `true` `false` (default `false`) |

## Examples

### Prompt only

```bash
curl -X POST https://mixmedia.tech/api/v1/jobs/createTask \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"kling-3.0","input":{"prompt":"A drone flies over an autumn forest at sunrise, fog, cinematic","resolution":"720p","aspect_ratio":"16:9","duration":"5"}}'
```

```python
import os, requests

r = requests.post(
    "https://mixmedia.tech/api/v1/jobs/createTask",
    headers={"Authorization": f"Bearer {os.environ['API_KEY']}"},
    json={
      "model": "kling-3.0",
      "input": {
        "prompt": "A drone flies over an autumn forest at sunrise, fog, cinematic",
        "resolution": "720p",
        "aspect_ratio": "16:9",
        "duration": "5"
      }
    },
)
print(r.json())  # {"code": 200, "data": {"taskId": "..."}}
```

```javascript
const r = await fetch("https://mixmedia.tech/api/v1/jobs/createTask", {
  method: "POST",
  headers: { Authorization: `Bearer ${process.env.API_KEY}`, "Content-Type": "application/json" },
  body: JSON.stringify({
    "model": "kling-3.0",
    "input": {
      "prompt": "A drone flies over an autumn forest at sunrise, fog, cinematic",
      "resolution": "720p",
      "aspect_ratio": "16:9",
      "duration": "5"
    }
  }),
});
console.log(await r.json()); // { code: 200, data: { taskId: "..." } }
```

### With a first frame

```bash
curl -X POST https://mixmedia.tech/api/v1/jobs/createTask \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"kling-3.0","input":{"prompt":"The character slowly turns to the camera, the wind moves the hair","first_frame_url":"https://mixmedia.tech/static/img/previews/gpt-t2i.jpg","resolution":"720p","duration":"5"}}'
```

```python
import os, requests

r = requests.post(
    "https://mixmedia.tech/api/v1/jobs/createTask",
    headers={"Authorization": f"Bearer {os.environ['API_KEY']}"},
    json={
      "model": "kling-3.0",
      "input": {
        "prompt": "The character slowly turns to the camera, the wind moves the hair",
        "first_frame_url": "https://mixmedia.tech/static/img/previews/gpt-t2i.jpg",
        "resolution": "720p",
        "duration": "5"
      }
    },
)
print(r.json())  # {"code": 200, "data": {"taskId": "..."}}
```

```javascript
const r = await fetch("https://mixmedia.tech/api/v1/jobs/createTask", {
  method: "POST",
  headers: { Authorization: `Bearer ${process.env.API_KEY}`, "Content-Type": "application/json" },
  body: JSON.stringify({
    "model": "kling-3.0",
    "input": {
      "prompt": "The character slowly turns to the camera, the wind moves the hair",
      "first_frame_url": "https://mixmedia.tech/static/img/previews/gpt-t2i.jpg",
      "resolution": "720p",
      "duration": "5"
    }
  }),
});
console.log(await r.json()); // { code: 200, data: { taskId: "..." } }
```

## Create and result

1. `POST /api/v1/jobs/createTask` with `model` and `input`.
2. Poll `GET /api/v1/jobs/recordInfo?taskId=…` every 3–5 s (or a [callback](https://docs.mixmedia.tech/en/callbacks)).

### Successful createTask (HTTP 200)

```json
{
  "code": 200,
  "msg": "success",
  "data": {
    "taskId": "task_...",
    "task_id": "task_...",
    "status": "submitted"
  }
}
```

### Completed task (recordInfo)

```json
{
  "code": 200,
  "msg": "success",
  "data": {
    "taskId": "task_...",
    "task_id": "task_...",
    "state": "success",
    "status": "completed",
    "costUsd": "0.384",
    "refunded": false,
    "resultJson": {
      "videos": [
        {
          "url": "https://…/out.mp4"
        }
      ],
      "duration": 8
    }
  }
}
```

Aliases: `task_id` = `taskId`; `status`: `pending` / `processing` / `completed` / `failed` alongside `state`. Clip URL is in `resultJson`. `size` is an alias of `aspect_ratio` in `input`.


Photos can be any public https links or uploads via [files/upload](https://docs.mixmedia.tech/en/endpoints/upload). Videos and audio — via files/upload only.

## Error handling

API responses are JSON `{"code", "msg", "data"}`; errors also have a string `error` field (type). **On `/api/v1/*` the HTTP status matches body `code`.**

### Example response bodies

**400**

```json
{
  "code": 400,
  "msg": "input.duration: must be between 4 and 30, or \"auto\" / -1",
  "data": null,
  "error": "invalid_request_error"
}
```

**401**

```json
{
  "code": 401,
  "msg": "Authentication failed. Please check your API key",
  "data": null,
  "error": "authentication_error"
}
```

**402**

```json
{
  "code": 402,
  "msg": "Insufficient balance. Please top up and try again. Available: $0.01, required: $0.015. Top up at https://mixmedia.tech/cabinet/billing",
  "data": {
    "balance": "0.0100",
    "required": "0.0150",
    "currency": "USD",
    "topUpUrl": "https://mixmedia.tech/cabinet/billing"
  },
  "error": "payment_required"
}
```

**429**

```json
{
  "code": 429,
  "msg": "Rate limit exceeded: 10 createTask/upload requests per 10 s per key. Retry after 8s",
  "data": null,
  "error": "rate_limit_error"
}
```

**500**

```json
{
  "code": 500,
  "msg": "Internal server error",
  "data": null,
  "error": "server_error"
}
```

### Codes on createTask / upload

| code | error | Meaning | What to do |
|---|---|---|---|
| 400 | `invalid_request_error` | Invalid parameter or body | See `msg` |
| 400 | `unsupported_model` | Unknown model | [Model list](https://docs.mixmedia.tech/en/models) |
| 400 | `nsfw_content_detected` | Moderation / content policy — `msg` / `failMsg` is the upstream text verbatim | Read the refusal text, change the prompt or files |
| 401 | `authentication_error` | Missing or invalid key | Check the key |
| 402 | `payment_required` | Not enough balance | Top up |
| 403 | `permission_error` | No access | Contact support |
| 429 | `rate_limit_error` | Too many requests | Wait for `Retry-After` |
| 505 | `model_disabled` | Model temporarily disabled | Pick another |
| 500 | `server_error` | Our failure | Retry later |

Example `msg` values: `Authentication failed. Please check your API key` (401); `Insufficient balance. Please top up and try again…` (402).

### Task errors (recordInfo)

If the task was created and then failed: `state: "fail"` (alias `status: "failed"`), `failCode` / `failMsg`, and `error: { code, message, type }`. Money is refunded (`refunded: true`).

| failCode | error.type | Meaning |
|---|---|---|
| 400 | `nsfw_content_detected` / `invalid_request_error` | Moderation — `failMsg` is upstream text verbatim |
| 422 | `invalid_request_error` | The model rejected the parameters (length, mode, resolution, file) |
| 501 | `server_error` | The model could not generate (`failMsg`) |
| 504 | `timeout_error` | Timed out — retry |
| 500 / 503 | `server_error` | Service temporarily unavailable |

### Rate limits

| What | Limit |
|---|---|
| createTask and upload | 20 per 10 s per key |
| recordInfo / list / balance | 100 per 10 s per key |

Over the limit — HTTP 429 and `Retry-After`.