# FLUX.1 Kontext [dev]

> Black Forest Labs' open-weights multimodal flow transformer for in-context image generation and editing, available for non-commercial use with character consistency and style transfer capabilities

## Quick Reference

- Model ID: flux.1-kontext-dev
- Creator: Black Forest Labs
- Status: active
- Family: flux.1-kontext
- Base URL: https://api.lumenfall.ai/openai/v1

## Specifications

- Max Resolution: 2048x2048
- Max Input Images: 4
- Input Modalities: text, image
- Output Modalities: image

## Model Identifiers

- Primary Slug: flux.1-kontext-dev

## Dates


## Tags

image-generation, text-to-image, image-editing, open-weights, non-commercial

## Available Providers

### Replicate

- Config Key: replicate/flux.1-kontext-dev
- Provider Model ID: black-forest-labs/flux-kontext-dev
- Pricing:
  - source: official
  - currency: USD
  - components: [{"type" => "output", "metric" => "image", "unit_price" => 0.025}]
  - source_url: https://replicate.com/black-forest-labs/flux-kontext-dev
  - effective_at: 2025-12-30

### fal.ai

- Config Key: fal/flux.1-kontext-dev
- Provider Model ID: fal-ai/flux-kontext/dev/text-to-image
- Pricing:
  - source: official
  - currency: USD
  - components: [{"type" => "output", "metric" => "image", "unit_price" => 0.025}]
  - source_url: https://fal.ai/models/fal-ai/flux-kontext/dev
  - effective_at: 2025-12-28


## Image Gallery

3 images available for this model.
- Curated examples: 3
  - "A wide, cinematic shot of a high-end, minimalist creative studio at golden hour. On a polished concrete wall, the nam..."
  - "A hyper-realistic close-up shot of a vintage leather explorer's satchel resting on a rustic wooden table in a sunlit ..."
  - "A cozy indie bookstore storefront with a large glass window displaying a hand-painted sign that reads "LOFI & LITERAT..."

## Example Prompt

The following prompt was used to generate an example image in our playground:

A cozy indie bookstore storefront with a large glass window displaying a hand-painted sign that reads "LOFI & LITERATURE" in elegant serif typography. In the background shadows near the reading nook, a capybara is calmly napping on a rug.

## Code Examples

### Text to Image (Generation)

#### cURL

curl -X POST \
  https://api.lumenfall.ai/openai/v1/images/generations \
  -H "Authorization: Bearer $LUMENFALL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "flux.1-kontext-dev",
    "prompt": "A serene mountain landscape at sunset",
    "size": "1024x1024"
  }'

# Response:
# { "created": 1234567890, "data": [{ "url": "https://...", "revised_prompt": "..." }] }

#### JavaScript

import OpenAI from 'openai';

const client = new OpenAI({
  apiKey: 'YOUR_API_KEY',
  baseURL: 'https://api.lumenfall.ai/openai/v1'
});

const response = await client.images.generate({
  model: 'flux.1-kontext-dev',
  prompt: 'A serene mountain landscape at sunset',
  size: '1024x1024'
});

// { created: 1234567890, data: [{ url: "https://...", revised_prompt: "..." }] }
console.log(response.data[0].url);

#### Python

from openai import OpenAI

client = OpenAI(
    api_key="YOUR_API_KEY",
    base_url="https://api.lumenfall.ai/openai/v1"
)

response = client.images.generate(
    model="flux.1-kontext-dev",
    prompt="A serene mountain landscape at sunset",
    size="1024x1024"
)

# { created: 1234567890, data: [{ url: "https://...", revised_prompt: "..." }] }
print(response.data[0].url)

### Image Editing

#### cURL

curl -X POST \
  https://api.lumenfall.ai/openai/v1/images/edits \
  -H "Authorization: Bearer $LUMENFALL_API_KEY" \
  -F "model=flux.1-kontext-dev" \
  -F "image=@source.png" \
  -F "prompt=Add a starry night sky to this image" \
  -F "size=1024x1024"

# Response:
# { "created": 1234567890, "data": [{ "url": "https://...", "revised_prompt": "..." }] }

#### JavaScript

import OpenAI from 'openai';
import fs from 'fs';

const client = new OpenAI({
  apiKey: 'YOUR_API_KEY',
  baseURL: 'https://api.lumenfall.ai/openai/v1'
});

const response = await client.images.edit({
  model: 'flux.1-kontext-dev',
  image: fs.createReadStream('source.png'),
  prompt: 'Add a starry night sky to this image',
  size: '1024x1024'
});

// { created: 1234567890, data: [{ url: "https://...", revised_prompt: "..." }] }
console.log(response.data[0].url);

#### Python

from openai import OpenAI

client = OpenAI(
    api_key="YOUR_API_KEY",
    base_url="https://api.lumenfall.ai/openai/v1"
)

response = client.images.edit(
    model="flux.1-kontext-dev",
    image=open("source.png", "rb"),
    prompt="Add a starry night sky to this image",
    size="1024x1024"
)

# { created: 1234567890, data: [{ url: "https://...", revised_prompt: "..." }] }
print(response.data[0].url)


## About

## Overview
FLUX.1 Kontext [dev] is an open-weights multimodal flow transformer developed by Black Forest Labs, designed specifically for in-context image generation and editing. It extends the foundational FLUX.1 architecture to allow for complex image-to-image workflows, enabling users to maintain consistent characters or styles across different compositions. This model is intended for non-commercial development and research, offering a high-fidelity bridge between text prompts and visual reference inputs.

## Strengths
*   **Character Consistency:** The model excels at maintaining the identity and features of a specific subject across multiple generated frames by leveraging reference images as "context."
*   **Zero-Shot Style Transfer:** It can adapt the aesthetic, color palette, and texture of a target image onto a new prompt without requiring specific LoRA training or fine-tuning.
*   **Complex Attribute Mapping:** It demonstrates high accuracy in following dense textual instructions while respecting the spatial constraints and structural information provided in the input image.
*   **Prompt Adherence:** Like other models in the FLUX.1 family, it minimizes common artifacts in hand rendering and manages high-density text within images effectively.

## Limitations
*   **Non-Commercial License:** The [dev] version is released under a restrictive license that prohibits revenue-generating applications, making it unsuitable for production environments without further licensing.
*   **Hardware Intensity:** Due to the flow transformer architecture and the multimodal input requirements, it demands significant VRAM and compute compared to standard latent diffusion models.
*   **Prompt Sensitivity:** Achieving the perfect balance between the input image context and the text prompt can require iterative testing, as the model may occasionally over-index on the reference image at the expense of prompt instructions.

## Technical Background
FLUX.1 Kontext [dev] is built on a multimodal flow transformer architecture, a departure from traditional U-Net-based diffusion models. This approach uses flow matching to improve training efficiency and sampling quality. By integrating text and image embeddings into a shared latent space, the model treats visual context as a primary input alongside textual tokens, allowing for more natural in-context learning during the generation process.

## Best For
FLUX.1 Kontext [dev] is best suited for storyboarding, character design sheets, and stylistic exploration where visual continuity is required across a series of images. It is an excellent choice for developers experimenting with advanced image-editing pipelines or researchers studying multimodal integration in large-scale generative models. You can experiment with its in-context capabilities through the Lumenfall unified API and playground, which simplifies the integration of its multimodal inputs into your development workflow.

## Frequently Asked Questions

### How much does FLUX.1 Kontext [dev] cost?

FLUX.1 Kontext [dev] starts at $0.025 per image through Lumenfall. Pricing varies by provider. Lumenfall does not add any markup to provider pricing.

### How do I use FLUX.1 Kontext [dev] via API?

You can use FLUX.1 Kontext [dev] through Lumenfall's OpenAI-compatible API. Send requests to the unified endpoint with model ID "flux.1-kontext-dev". Code examples are available in Python, JavaScript, and cURL.

### Which providers offer FLUX.1 Kontext [dev]?

FLUX.1 Kontext [dev] is available through Replicate and fal.ai on Lumenfall. Lumenfall automatically routes requests to the best available provider.

### What is the maximum resolution for FLUX.1 Kontext [dev]?

FLUX.1 Kontext [dev] supports images up to 2048x2048 resolution.

## Links

- Model Page: https://lumenfall.ai/models/black-forest-labs/flux.1-kontext-dev
- About: https://lumenfall.ai/models/black-forest-labs/flux.1-kontext-dev/about
- Providers, Pricing & Performance: https://lumenfall.ai/models/black-forest-labs/flux.1-kontext-dev/providers
- API Reference: https://lumenfall.ai/models/black-forest-labs/flux.1-kontext-dev/api
- Benchmarks: https://lumenfall.ai/models/black-forest-labs/flux.1-kontext-dev/benchmarks
- Use Cases: https://lumenfall.ai/models/black-forest-labs/flux.1-kontext-dev/use-cases
- Gallery: https://lumenfall.ai/models/black-forest-labs/flux.1-kontext-dev/gallery
- Playground: https://lumenfall.ai/playground?model=flux.1-kontext-dev
- API Documentation: https://docs.lumenfall.ai