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Black Forest LabsImage Generation/v1/media/queue

FLUX.2 Klein

FLUX.2 Klein from $0.03 per image — the compact 4B FLUX model for high-volume generation.

The compact 4B FLUX.2 model. Fast, cheap image generation from $0.03 with the full FLUX.2 aspect-ratio range and reference-image editing.

No credit card required. Takes 30 seconds.

2,400+

Developers

1.2M+

API calls served

100+

Endpoints

$0.01

Per call

Yep, that's it.

Try it live

Enter a prompt and generate an image with FLUX.2 Klein.

POST/v1/media/queue

Drop image or click to upload

For image-to-image editing

Response
Hit "Send Request" to see the response

Pricing

Per-image: from $0.03/image

Endpoint

/v1/media/queue

Strengths

Cheapest FLUX tier

At around $0.03 per image, Klein makes large batches, thumbnails, and prompt exploration affordable at volume.

Fast turnaround

The compact 4B architecture renders quickly, keeping iteration loops tight when you are still hunting for the right prompt.

Full aspect-ratio range

Supports the same nine aspect ratios as the larger FLUX.2 tiers, so drafts frame identically to finals.

Draft-then-promote

Explore on Klein, then re-run the winning prompts on FLUX.2 Pro or Max — same family, same endpoint, one key.

Quick start

Copy this snippet and start making calls with FLUX.2 Klein.

// Step 1: Submit job
const res = await fetch('https://api.yepapi.com/v1/media/queue', {
  method: 'POST',
  headers: {
    'x-api-key': 'YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    "model": "black-forest-labs/flux.2-klein-4b",
    "prompt": "Flat-lay of hiking gear on pale birch — enamel mug, folded topo map, worn leather boots, brass compass, soft overcast daylight, muted forest palette",
    "options": {
      "aspectRatio": "1:1"
    }
  }),
});
const { data } = await res.json();
const jobId = data.jobId;

// Step 2: Poll for result
const status = await fetch(`https://api.yepapi.com/v1/media/status/${jobId}`, {
  headers: { 'x-api-key': 'YOUR_API_KEY' },
});
const { data: job } = await status.json();
// job.status: "pending" | "processing" | "completed" | "failed"
// job.result: { text?, image?, audio?, video? }

Why use FLUX.2 Klein through YepAPI?

One API key for all models — no separate accounts
No monthly minimums — pay per call
Switch models with one line of code
Simple REST API — works from any language
Unified billing across all providers
No rate limits for most use cases

FLUX.2 Klein API — compact 4B image generation from $0.03

FLUX.2 Klein is the small, fast member of the FLUX.2 family — a 4-billion-parameter model built for volume. It keeps the FLUX aspect-ratio range and reference-image editing while cutting cost and render time dramatically.

On YepAPI, Klein costs about $0.03 per image on the shared `/v1/media/queue` endpoint, which makes it the natural first pass for prompt exploration, A/B creative, and batch thumbnail generation.

Start generating in 30 seconds

$5 free credit on signup. No credit card required. Pay per call.

What developers say

Switched from SerpAPI and cut our SERP costs by 80%. Same data quality, way simpler billing.

Marcus T.

SEO Platform Founder

One API key for AI models, SERP data, and web scraping. Saved us from managing 4 separate providers.

Priya S.

Full-Stack Developer

The $5 free credit let us prototype our entire rank tracking feature before committing. No other API does that.

Jake R.

Indie Hacker

Frequently asked questions

The compact 4B FLUX.2 model. Fast, cheap image generation from $0.03 with the full FLUX.2 aspect-ratio range and reference-image editing.

Pricing for FLUX.2 Klein through YepAPI is based on usage. No monthly minimums — you only pay for what you use.

Sign up for a free API key, then send requests to the /v1/media/queue endpoint.

Ready to use FLUX.2 Klein?

$5 free credit on signup. No credit card required. Pay per call.

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