> ## Documentation Index
> Fetch the complete documentation index at: https://doc.starrise.tech/llms.txt
> Use this file to discover all available pages before exploring further.

# FLUX.2 [flex]

> Call the Black Forest Labs FLUX.2 [flex] text-to-image model via the Starrise AI API.

FLUX.2 \[flex] is a highly configurable text-to-image model from Black Forest Labs, available through Starrise AI. It offers fine-grained control over sampling steps and guidance scale, ideal for design professionals. The API uses **synchronous calls** — it directly returns Base64-encoded image data.

## Key Capabilities

* **Text-to-image** — Generate images from text descriptions
* **Step control** — Adjust sampling steps (1–50) to flexibly balance speed and quality
* **Guidance scale** — Fine-tune prompt adherence (1.5–10)
* **High resolution** — supports up to 4MP output resolution
* **Reproducible** — Use `seed` for deterministic generation

## Quick Example

<CodeGroup>
  ```bash cURL theme={null}
  curl https://ai.alad.com/v1/images/generations \
    -H "Authorization: Bearer YOUR_API_KEY" \
    -H "Content-Type: application/json" \
    -d '{
      "model": "flux-2-flex",
      "prompt": "A cute baby polar bear",
      "size": "1024x1024",
      "inference_steps": 30,
      "guidance_scale": 7.5
    }'
  ```

  ```python Python theme={null}
  import requests

  response = requests.post(
      "https://ai.alad.com/v1/images/generations",
      headers={"Authorization": "Bearer YOUR_API_KEY"},
      json={
          "model": "flux-2-flex",
          "prompt": "A cute baby polar bear",
          "size": "1024x1024",
          "inference_steps": 30,
          "guidance_scale": 7.5
      }
  )

  result = response.json()
  # result["data"][0]["b64_json"] contains the Base64-encoded image
  ```
</CodeGroup>

## Parameters

| Parameter         | Type    | Required | Description                                                                                  |
| ----------------- | ------- | -------- | -------------------------------------------------------------------------------------------- |
| `model`           | string  | Yes      | Fixed value: `flux-2-flex`                                                                   |
| `prompt`          | string  | Yes      | Text description for the image                                                               |
| `n`               | integer | No       | Number of images to generate (1–4), default `1`                                              |
| `size`            | string  | No       | Output resolution, e.g. `1024x1024`, supports up to 4MP                                      |
| `inference_steps` | integer | No       | Sampling steps (1–50). Low steps (6–20) for rapid prototyping, high (40–50) for max fidelity |
| `guidance_scale`  | number  | No       | Guidance scale (1.5–10). Higher values produce closer adherence to the prompt                |
| `output_format`   | string  | No       | `jpeg` or `png`                                                                              |
| `seed`            | integer | No       | Random seed for reproducibility                                                              |

## Response Fields

| Field             | Description               |
| ----------------- | ------------------------- |
| `data[].b64_json` | Base64-encoded image data |
| `created`         | Creation timestamp        |

<Card title="API Reference" icon="code" href="/en/api-reference/model-api/blackforestlabs/flux-2-flex">
  View the interactive API Playground for FLUX.2 \[flex].
</Card>