FLUX.2 Klein 4B API
Black Forest Labs
FLUX.2 Klein 4B (per-megapixel) via OpenRouter.
About FLUX.2 Klein 4B
FLUX.2 Klein 4B is a large language model developed by Black Forest Labs. It's particularly well-suited for producing structured outputs for reliable data extraction. Developers choose FLUX.2 Klein 4B when they need reliable, production-quality AI inference through a simple API — and on Qubax, it's available at a fraction of the cost of traditional providers.
In the broader AI landscape, FLUX.2 Klein 4B sits among the capable offerings from Black Forest Labs What sets it apart on Qubax isn't just the model itself — it's the accessibility. Rather than dealing with enterprise contracts or traditional payment rails, you get instant access via an OpenAI-compatible endpoint. That means you can drop FLUX.2 Klein 4B into Cursor, Cline, LangChain, or any framework that speaks the OpenAI protocol and start building immediately.
Qubax offers FLUX.2 Klein 4B at competitive rates — just Free per million input tokens and Free per million output tokens. That pricing advantage compounds quickly at scale: a high-volume application sending millions of tokens per day can save significantly compared to using OpenRouter or the provider directly. And because Qubax runs on crypto-native infrastructure, you can pay with USDC, USDT, ETH, BTC, or 200+ other cryptocurrencies — no credit card or bank account required. New users even get $1 in free credits to test FLUX.2 Klein 4B risk-free before committing.
Pricing
| Token Type | Qubax | OpenRouter | You Save |
|---|---|---|---|
| Input (per 1M tokens) | Free | Free | — |
| Output (per 1M tokens) | Free | Free | — |
Prices per 1 million tokens. Pay with 200+ cryptocurrencies.
Estimated Monthly Cost
Specifications
Use Cases
Capabilities
Quick Start
from openai import OpenAI
client = OpenAI(
base_url="https://api.qubax.ai/v1",
api_key="qbx_live_YOUR_API_KEY",
)
response = client.chat.completions.create(
model="flux.2-klein-4b",
messages=[
{"role": "user", "content": "Hello!"}
],
)
print(response.choices[0].message.content)import OpenAI from "openai";
const client = new OpenAI({
baseURL: "https://api.qubax.ai/v1",
apiKey: "qbx_live_YOUR_API_KEY",
});
const response = await client.chat.completions.create({
model: "flux.2-klein-4b",
messages: [{ role: "user", content: "Hello!" }],
});
console.log(response.choices[0].message.content);curl https://api.qubax.ai/v1/chat/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer qbx_live_YOUR_API_KEY" \
-d '{
"model": "flux.2-klein-4b",
"messages": [{"role": "user", "content": "Hello!"}]
}'Get your API key from the dashboard. New users get $1 free credits.
Why use FLUX.2 Klein 4B on Qubax?
Best Prices
Up to 99% off OpenRouter prices
Pay with Crypto
200+ coins (BTC, ETH, SOL, USDT, USDC & more). No credit card needed.
OpenAI Compatible
Drop-in replacement. Works with Cline, Cursor, any tool.
More from Black Forest Labs
Frequently Asked Questions
How much does the FLUX.2 Klein 4B API cost?
On Qubax, FLUX.2 Klein 4B costs Free per 1M input tokens and Free per 1M output tokens.
Is the FLUX.2 Klein 4B API compatible with OpenAI?
Yes. Qubax provides an OpenAI-compatible API. You can use FLUX.2 Klein 4B as a drop-in replacement by changing your base URL to https://api.qubax.ai/v1 and using your Qubax API key. It works with Cline, Cursor, OpenCode, Hermes Agent, and any tool that supports OpenAI APIs.
How do I pay for FLUX.2 Klein 4B API usage?
Qubax uses prepaid crypto credits. Deposit USDC on the Base chain and your balance is automatically deducted as you use the API. New users get $1 in free credits to start. No credit card required.
What can I build with FLUX.2 Klein 4B?
FLUX.2 Klein 4B is versatile enough for a wide range of applications. You can use it to generate structured JSON output for data pipelines, and more. Because it's served through Qubax's OpenAI-compatible API, integration into existing apps, agents, or workflows takes just a few lines of code.
How fast is FLUX.2 Klein 4B on Qubax?
FLUX.2 Klein 4B on Qubax supports streaming responses, so tokens begin arriving in real time as they're generated. Latency depends on the provider and prompt complexity, but most requests start streaming within 200–800 milliseconds. Qubax routes requests through the Surplus Intelligence marketplace, which selects the fastest available compute provider for each request — so you get competitive latency at a lower price.
Can I use FLUX.2 Klein 4B for commercial projects?
Yes. FLUX.2 Klein 4B on Qubax can be used for commercial purposes. You own the outputs you generate. Qubax provides the API infrastructure — you bring your use case.
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