# FLUX.1 Kontext [pro] API (Black Forest Labs)

> FLUX.1 Kontext [pro] edits images with plain-language instructions — change clothes, scenes, text or style — while keeping people and objects consistent, at a flat price per image. BFL now lists Kontext as a legacy model; FLUX.2 and FLUX 3 are its successors.

Page: https://cheapergen.com/models/bfl/flux-kontext-pro · API reference: https://cheapergen.com/models/bfl/flux-kontext-pro/api

## Pricing
Official list price source: BFL API list price for FLUX.1 Kontext [pro] ($0.04 per image). Prices verified 2026-10-16.

| Tier | Official | Cheaper Gen. | Save |
|---|---|---|---|
| Image | $0.0400/image | $0.0275/image | 31% |

## Specs
- Resolution: ≈1 MP
- Aspect ratios: 1:1 · 4:3 · 3:4 · 16:9 · 9:16 · 3:2 · 2:3 · 21:9 · 9:21
- Edit inputs: Up to 4 images

## Endpoints

### Text to Image — `POST https://cheapergen.com/api/v1/run/bfl/flux-kontext-pro/text-to-image`

| Param | Type | Required | Description |
|---|---|---|---|
| prompt | string | yes | Describe the shot: subject, action, camera movement, lighting and style. |
| aspect_ratio | string (enum) (1:1, 4:3, 3:4, 16:9, 9:16, 3:2, 2:3, 21:9, 9:21) | no | Output image shape. |
| seed | integer | no | Use the same seed and settings to reproduce a result. Leave empty for random. |

```bash
curl -X POST https://cheapergen.com/api/v1/run/bfl/flux-kontext-pro/text-to-image \
  -H "Authorization: Bearer $CHEAPERGEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "prompt": "A cozy reading nook with a window seat, rain outside, warm lamplight, illustrated children'\''s-book style",
  "aspect_ratio": "1:1"
}'
```

### Image Edit — `POST https://cheapergen.com/api/v1/run/bfl/flux-kontext-pro/edit`

| Param | Type | Required | Description |
|---|---|---|---|
| prompt | string | yes | Describe the shot: subject, action, camera movement, lighting and style. |
| image_urls | string[] (URLs) | yes | Up to 4 reference images to edit or combine. Refer to them as "image 1", "image 2"… in the prompt. |
| aspect_ratio | string (enum) (1:1, 4:3, 3:4, 16:9, 9:16, 3:2, 2:3, 21:9, 9:21) | no | Output image shape. |
| seed | integer | no | Use the same seed and settings to reproduce a result. Leave empty for random. |

```bash
curl -X POST https://cheapergen.com/api/v1/run/bfl/flux-kontext-pro/edit \
  -H "Authorization: Bearer $CHEAPERGEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "prompt": "Change the jacket to red leather and make it night time; keep her face and pose exactly the same",
  "image_urls": [
    "https://cdn.cheapergen.ai/samples/portrait.jpg"
  ],
  "aspect_ratio": "1:1"
}'
```

## Getting the result
Jobs are async. Poll `GET https://cheapergen.com/api/v1/generations/{id}` until status is succeeded/failed/canceled, or pass `webhook_url`. Failed generations are refunded automatically.

## FAQ
**How is FLUX.1 Kontext [pro] priced?**
FLUX.1 Kontext [pro] is billed at a flat price per image (about 1 megapixel), including input images. Failed generations are not charged.

**Is this the official FLUX.1 Kontext [pro]?**
Yes. Requests run on Black Forest Labs' FLUX.1 Kontext [pro] model through official API channels, at a lower price than the BFL list price.

**Can I use the output commercially?**
Yes, outputs of the FLUX API models can be used commercially, subject to Black Forest Labs' terms and our Terms of Service.

FLUX.1 Kontext [pro] is developed by Black Forest Labs. Cheaper Gen. provides API access and does not own the model.