models/Black Forest Labs/Flux-2-Klein-9b

Black Forest Labs

Flux-2-Klein-9b

image

FLUX.2 [klein] 9B is a 9 billion parameter model that can generate images from text descriptions and supports multi-reference editing capabilities.

MODALITIES

image

PER IMAGE

$0.040

RELEASED

2026-01-14

Flux-2-Klein-9b (black-forest-labs/flux-2-klein-9b) is a image model from Black Forest Labs, released 2026-01-14. Pricing via AIgateway: $0.040 per image. Call it via https://api.aigateway.sh/v1/images/generations — set model="black-forest-labs/flux-2-klein-9b". Best for: Marketing assets, Product photos, UI mockups.

model · black-forest-labs/flux-2-klein-9bfamily · FLUX

Use this model

model: black-forest-labs/flux-2-klein-9b

curl https://api.aigateway.sh/v1/images/generations \
  -H "Authorization: Bearer $AIGATEWAY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"black-forest-labs/flux-2-klein-9b","prompt":"a serene cyberpunk city at dusk"}'

curl https://api.aigateway.sh/v1/images/generations \ -H "Authorization: Bearer $AIGATEWAY_API_KEY" \ -H "Content-Type: application/json" \ -d '{"model":"black-forest-labs/flux-2-klein-9b","prompt":"a cyberpunk cat"}'

Capabilities

Strengths

Photorealism
Text rendering
Fast generation

Use cases

Marketing assetsProduct photosUI mockups

Pricing

Per image$0.040

1024x1024, ~3s generation

You pay pass-through · 5% applied at credit top-up, not per-call.

See API example →Compare API reference See usage ranking →

Collections

More image models →More from Black Forest Labs →Frontier models →Free-tier models →

API schema

Call Flux-2-Klein-9b from any OpenAI SDK

POST https://api.aigateway.sh/v1/images/generations·Content-Type: application/json·Auth: Bearer sk-aig-...

Request body

json

{
  "model": "black-forest-labs/flux-2-klein-9b",
  "prompt": "A cyberpunk cat at sunset, cinematic lighting",
  "n": 1,
  "size": "1024x1024",
  "response_format": "url"   // or "b64_json"
}

Response

json

{
  "created": 1776947082,
  "data": [
    { "url": "https://media.aigateway.sh/img/abc123.png" }
    // or { "b64_json": "iVBORw0KGgoAAAANSUhEU..." }
  ]
}

Quickstart

from openai import OpenAI
client = OpenAI(base_url="https://api.aigateway.sh/v1", api_key="sk-aig-...")

r = client.images.generate(
    model="black-forest-labs/flux-2-klein-9b",
    prompt="a cyberpunk cat at sunset",
    size="1024x1024",
)
print(r.data[0].url)

Errors

401authentication_errorInvalid or missing API key

402insufficient_creditsWallet empty (PAYG only)

404not_foundUnknown model or endpoint

429rate_limit_errorOver per-minute limit — see Retry-After header

500server_errorUpstream provider failed (retryable)

503service_unavailableUpstream saturated (retryable)

Full docs →API reference →OpenAPI spec →llms.txt →

Frequently asked questions

What is Flux-2-Klein-9b?

FLUX.2 [klein] 9B is a 9 billion parameter model that can generate images from text descriptions and supports multi-reference editing capabilities. It is a image model from Black Forest Labs, accessible via AIgateway's OpenAI-compatible API at slug black-forest-labs/flux-2-klein-9b.

How much does Flux-2-Klein-9b cost via AIgateway?

$0.0400 per image. Pass-through plus a 5% platform fee applied at top-up.

How do I call Flux-2-Klein-9b from my code?

Point the OpenAI SDK at https://api.aigateway.sh/v1 with your AIgateway key and set model to "black-forest-labs/flux-2-klein-9b". The request and response shapes match OpenAI exactly.

Does Flux-2-Klein-9b support streaming, tool calling, vision, and JSON mode?

Streaming — no. Tool calling — no. Vision — no. JSON mode — no. Prompt caching — no.

What are the best use cases for Flux-2-Klein-9b?

Marketing assets, Product photos, UI mockups. Key strengths: Photorealism; Text rendering; Fast generation.

Can I bring my own Black Forest Labs API key (BYOK)?

Yes. Attach a Black Forest Labs key in your AIgateway dashboard and this model flips to pass-through — you pay Black Forest Labs directly and AIgateway waives the 5% platform fee on those calls.