Black Forest Labs Image Generation

Black Forest Labs provides state-of-the-art text-to-image generation using their FLUX models.

Overview

Setup

API Key

# Set your Black Forest Labs API key
os.environ["BFL_API_KEY"] = "your-api-key-here"

Get your API key from Black Forest Labs.

Supported Models

Image Generation

Usage - LiteLLM Python SDK

# Set your API key
os.environ["BFL_API_KEY"] = "your-api-key-here"

# Generate an image
response = litellm.image_generation(
    model="black_forest_labs/flux-pro-1.1",
    prompt="A beautiful sunset over the ocean with sailing boats",
)

# BFL returns URLs
print(response.data[0].url)

# Set your API key
os.environ["BFL_API_KEY"] = "your-api-key-here"

async def generate_image():
    response = await litellm.aimage_generation(
        model="black_forest_labs/flux-pro-1.1",
        prompt="A futuristic city skyline at night",
    )
    print(response.data[0].url)

# Run the async function
asyncio.run(generate_image())

# Set your API key
os.environ["BFL_API_KEY"] = "your-api-key-here"

# Generate with specific dimensions
response = litellm.image_generation(
    model="black_forest_labs/flux-pro-1.1",
    prompt="A majestic mountain landscape",
    size="1792x1024",  # Maps to width/height
)

print(response.data[0].url)

# Set your API key
os.environ["BFL_API_KEY"] = "your-api-key-here"

# Generate ultra high-resolution image
response = litellm.image_generation(
    model="black_forest_labs/flux-pro-1.1-ultra",
    prompt="Detailed portrait of a fantasy character",
    size="2048x2048",    # Up to 4MP supported
    quality="hd",        # Maps to raw=True for natural look
)

print(response.data[0].url)

# Set your API key
os.environ["BFL_API_KEY"] = "your-api-key-here"

# Generate with BFL-specific parameters
response = litellm.image_generation(
    model="black_forest_labs/flux-pro-1.1",
    prompt="A cute orange cat sitting on a windowsill",
    seed=42,                    # For reproducible results
    output_format="png",        # png or jpeg
    safety_tolerance=2,         # 0-6, higher = more permissive
    prompt_upsampling=True,     # Enhance prompt for better results
)

print(response.data[0].url)

Usage - LiteLLM Proxy Server

1. Configure your config.yaml

model_list:
  - model_name: flux-pro
    litellm_params:
      model: black_forest_labs/flux-pro-1.1
      api_key: os.environ/BFL_API_KEY
    model_info:
      mode: image_generation

  - model_name: flux-ultra
    litellm_params:
      model: black_forest_labs/flux-pro-1.1-ultra
      api_key: os.environ/BFL_API_KEY
    model_info:
      mode: image_generation

  - model_name: flux-dev
    litellm_params:
      model: black_forest_labs/flux-dev
      api_key: os.environ/BFL_API_KEY
    model_info:
      mode: image_generation

general_settings:
  master_key: sk-1234

2. Start LiteLLM Proxy Server

litellm --config /path/to/config.yaml

# RUNNING on http://0.0.0.0:4000

3. Make image generation requests

from openai import OpenAI

# Initialize client with your proxy URL
client = OpenAI(
    base_url="http://localhost:4000",
    api_key="sk-1234"
)

# Generate image with FLUX Pro
response = client.images.generate(
    model="flux-pro",
    prompt="A beautiful garden with colorful flowers",
    size="1024x1024",
)

print(response.data[0].url)

curl -X POST 'http://localhost:4000/v1/images/generations' \\
  -H 'Content-Type: application/json' \\
  -H 'Authorization: Bearer sk-1234' \\
  -d '{
    "model": "flux-pro",
    "prompt": "A beautiful garden with colorful flowers",
    "size": "1024x1024"
  }'

Supported Parameters

OpenAI-Compatible Parameters

Black Forest Labs Specific Parameters

Ultra Model Specific Parameters

How It Works

Black Forest Labs uses a polling-based API:

1. Submit Request: LiteLLM sends your prompt to BFL
2. Get Task ID: BFL returns a task ID and polling URL
3. Poll for Result: LiteLLM automatically polls until the image is ready
4. Return Result: The generated image URL is returned

This polling is handled automatically by LiteLLM - you just call image_generation() and get the result.

Getting Started

1. Create an account at Black Forest Labs
2. Get your API key from the dashboard
3. Set your BFL_API_KEY environment variable
4. Use litellm.image_generation() with any supported model

Additional Resources

• Black Forest Labs Documentation
• Black Forest Labs Image Editing - For editing existing images
• FLUX Model Information