Black Forest Labs: FLUX.2 Klein 4B

black-forest-labs/flux.2-klein-4b

41KContext Window

Supported Protocols:seed

Online

FLUX.2 [klein] 4B is the fastest and most cost-effective model in the FLUX.2 family, optimized for high-throughput use cases while maintaining excellent image quality. Pricing is based on the output image. The first generated megapixel is charged $0.014. Each subsequent megapixel is charged $0.001.

Capabilities

👁 VisionText GenerationCode GenerationAnalysis & Reasoningmodels.reasoning

Technical Specs

Input Modality

Text、Image

Output Modality

Image

Arch

—

Pricing

Pay per use, no monthly fees

Input Token< ¥0.001/1K Token

Output Token< ¥0.001/1K Token

Quick Start

from openai import OpenAI

client = OpenAI(
    base_url="https://api.uniontoken.ai/v1",
    api_key="YOUR_UNIONTOKEN_API_KEY",
)

response = client.chat.completions.create(
    model="black-forest-labs/flux.2-klein-4b",
    messages=[
        {"role": "user", "content": "Hello!"}
    ],
)

print(response.choices[0].message.content)