# Z-Image — API Reference

Model ID: `model_z-image`

---

## Authentication

Scenario API uses HTTP Basic Auth. Encode your credentials in Base64 and pass them as the `Authorization` header.

```
Authorization: Basic base64("<API_KEY>:<API_SECRET>")
```

- **API_KEY** and **API_SECRET** are found in your [Scenario Project Settings](https://app.scenario.com/team&tab=project_api_keys) under API Keys.
- In shell: `$(echo -n '<API_KEY>:<API_SECRET>' | base64)`
- In JavaScript: `btoa("<API_KEY>:<API_SECRET>")`
- In Python: `base64.b64encode(f"{api_key}:{api_secret}".encode()).decode()`

---

## Generate

**Endpoint:** `POST https://api.cloud.scenario.com/v1/generate/custom/model_z-image`

### Parameters

| Parameter | Type | Required | Default | Description |
|-----------|------|----------|---------|-------------|
| `modelId` | model | - | `` | A single LoRA model ID. If provided, it will be added to the loras array. |
| `loras` | model[] | - | `` | List of one or more LoRA model IDs. If modelId is a LoRA and this is not provided, it will be automatically populated with the modelId. |
| `lorasScale` | number[] | - | - | Scales for the LoRA weights |
| `prompt` | string | yes | - | Text prompt for image generation |
| `negativePrompt` | string | - | - | Text prompt for what to avoid in the image |
| `strength` | number | - | `0.6` | How much to transform the reference image. 0 means no change, 1 means complete transformation |
| `controlnetConditioningScale` | number | - | `0.75` | The scale of the controlnet conditioning |
| `numOutputs` | number | - | `4` | Number of images to generate |
| `numInferenceSteps` | number | - | `28` | Number of inference steps. |
| `width` | number | - | - | The width of the generated images, must be a multiple of 16 |
| `height` | number | - | - | The height of the generated images, must be a multiple of 16 |
| `guidance` | number | - | `5` | Controls how closely the generated image follows the prompt |
| `seed` | number | - | - | Used to reproduce previous results |

### Example Requests

**cURL**

```bash
curl -X POST "https://api.cloud.scenario.com/v1/generate/custom/model_z-image" \
  -H "Authorization: Basic $(echo -n '<API_KEY>:<API_SECRET>' | base64)" \
  -H "Content-Type: application/json" \
  --data-binary @- <<'EOF'
{
  "prompt": "A fantasy landscape",
  "strength": 0.6,
  "controlnetConditioningScale": 0.75,
  "numOutputs": 4,
  "numInferenceSteps": 28,
  "guidance": 5
}
EOF
```

**Python**

```python
import requests
import base64

api_key = "<API_KEY>"
api_secret = "<API_SECRET>"
token = base64.b64encode(f"{api_key}:{api_secret}".encode()).decode()

url = "https://api.cloud.scenario.com/v1/generate/custom/model_z-image"
headers = {
    "Authorization": f"Basic {token}",
    "Content-Type": "application/json"
}
payload = {
    "prompt": "A fantasy landscape",
    "strength": 0.6,
    "controlnetConditioningScale": 0.75,
    "numOutputs": 4,
    "numInferenceSteps": 28,
    "guidance": 5
}

response = requests.post(url, headers=headers, json=payload)
print(response.json())
```

**JavaScript**

```javascript
const token = btoa("<API_KEY>:<API_SECRET>");

const body = {
  "prompt": "A fantasy landscape",
  "strength": 0.6,
  "controlnetConditioningScale": 0.75,
  "numOutputs": 4,
  "numInferenceSteps": 28,
  "guidance": 5
};

const response = await fetch(
  "https://api.cloud.scenario.com/v1/generate/custom/model_z-image",
  {
    method: "POST",
    headers: {
      "Authorization": `Basic ${token}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify(body),
  }
);

const data = await response.json();
console.log(data);
```

---

## Retrieve Results

After submitting a generation request, you receive a `jobId`. Poll the job status endpoint until the job completes.

**Endpoint:** `GET https://api.cloud.scenario.com/v1/jobs/{jobId}`

**Headers:**
```
Authorization: Basic base64("<API_KEY>:<API_SECRET>")
```

Poll until `job.status` is `"success"`. The generated asset IDs are in `job.metadata.assetIds`.

**Example response:**
```json
{
  "job": {
    "jobId": "job_abc123",
    "status": "success",
    "metadata": {
      "assetIds": [
        "asset_abc123"
      ]
    }
  }
}
```

> **Important:** Generated asset URLs are **temporary** and expire after a short period. Download and store any images you wish to keep before the URL expires. More info: [Content Delivery Network (CDN)](https://docs.scenario.com/docs/content-delivery-network-cdn).

---

*Generated by [Scenario](https://app.scenario.com)*