FLUX.2 Klein 4B API

Compact 4B FLUX.2 model optimized for efficient generation.
Output
$0.0182 / megapixel (variable)
Released
Jun 12, 2026

How to use FLUX.2 Klein 4B API

Install any OpenAI-compatible SDK, point it at api.aimlapi.com/v1, and set the model to blackforestlabs/flux-2-klein-4b.
import requests

r = requests.post(
    "https://api.aimlapi.com/v1/images/generations",
    headers={"Authorization": "Bearer " + AIMLAPI_KEY},
    json={
      "model": "blackforestlabs/flux-2-klein-4b",
      "prompt": "A cat holding a sign that says hello"
    },
)
print(r.json())
const r = await fetch("https://api.aimlapi.com/v1/images/generations", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.AIMLAPI_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "model": "blackforestlabs/flux-2-klein-4b",
    "prompt": "A cat holding a sign that says hello"
  }),
});
console.log(await r.json());
curl -X POST https://api.aimlapi.com/v1/images/generations \
  -H "Authorization: Bearer $AIMLAPI_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"blackforestlabs/flux-2-klein-4b","prompt":"A cat holding a sign that says hello"}'

OpenAI-compatible — swap the base URL and it works with your existing SDK.

FLUX.2 Klein 4B API Pricing

TypePrice
Input
Output
$0.0182 / megapixel (variable) tokens

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