About FLUX 3 Klein
FLUX 3 Klein is the small, fast model of the FLUX 3 family from Black Forest Labs. It makes an image from a text prompt and can edit a photo you add.
It is the cheapest image model on Kinoseed, so it is the one to use for trying ideas: many variations of a prompt for the price of one image on the bigger models.
For the final image, FLUX 3 keeps more fine detail.
FLUX 3 Klein specs
| Made by | Black Forest Labs |
|---|---|
| Text to image | Yes |
| Reference image | Yes, routes to the model's edit mode |
| Aspect ratios | 1:1, 4:5, 3:4, 3:2, 16:9 or 9:16 |
| Images per run | 1, 2, 4 or 8 |
| Price | 3 credits per image |
FLUX 3 Klein price per run
Prices are in credits and come from the same quote the studio and the API charge. The exact price is on the Generate button before you spend anything, and a failed generation is refunded automatically. The dollar figure next to each price is at the standard rate of $0.02 a credit.
| Images | From a prompt | With a reference |
|---|---|---|
| 1 | 3$0.06 | 3$0.06 |
| 2 | 4$0.08 | 4$0.08 |
| 4 | 8$0.16 | 8$0.16 |
| 8 | 14$0.28 | 14$0.28 |
See plans.
One image in dollars
The cheapest FLUX 3 Klein run is 3 credits. What that comes to depends on how you buy credits; the Studio plan sells them cheapest.
| At the standard credit price$0.02 a credit | $0.06 |
|---|---|
| Basic plan$10 a month for 500 credits | $0.06 |
| Starter plan$20 a month for 1,200 credits | $0.05 |
| Creator plan$100 a month for 7,000 credits | $0.04 |
| Studio plan$200 a month for 15,000 credits, the lowest price per credit | $0.04 |
The smallest plan is the $10 Basic plan (500 credits a month).
FLUX 3 Klein API
Run FLUX 3 Klein from your own code with one POST to /api/v1/images and model id flux-3-klein. This request costs 3 credits ($0.06). Create a key on your account page and replace the placeholder.
curl -X POST https://kinoseed.app/api/v1/images \
-H "Authorization: Bearer ks_live_YOUR_KEY" \
-H "Content-Type: application/json" \
-d '{
"prompt": "a ceramic mug on a sunlit desk, product photo",
"model": "flux-3-klein",
"aspect": "1:1",
"count": 1
}'
Price any other settings first with POST /quote, which is free. Images usually finish within one wait on the job. Every field is described in the images docs.
FLUX 3 Klein from an AI agent (MCP)
Claude Code, Cursor and other MCP clients run the same request as the generate_image tool. Add the server once:
claude mcp add --transport http kinoseed https://kinoseed.app/api/mcp --header "Authorization: Bearer ks_live_YOUR_KEY"Then the agent sends this call, or you ask for the result in plain words and it builds the call itself:
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "generate_image",
"arguments": {
"prompt": "a ceramic mug on a sunlit desk, product photo",
"model": "flux-3-klein",
"aspect": "1:1",
"count": 1
}
}
}
Setup for every client is on the MCP server page.
Developer guides
- Image API with credits: An image generation API with credits: one prepaid balance for Nano Banana Pro, GPT Image 2, FLUX.2 and more, a free quote per call and refunds on failure.
- MCP server for images: A hosted MCP server for image generation and video: six tools, one API key, a quote before every run. Setup for Claude Code, Cursor, Windsurf and others.
- Claude Code and Cursor setup: How to give Claude Code image and video generation with one command: an API key, a remote MCP server and a budget rule. The same setup works in Cursor.
Frequently asked questions
What does FLUX 3 Klein cost?
Generating starts with a plan. One image with FLUX 3 Klein costs 3 credits, which the $10 Basic plan (500 credits a month) covers: 166 images. Results never carry a watermark.
What aspect ratios does FLUX 3 Klein support?
In the Kinoseed image studio you can pick 1:1, 4:5, 3:4, 3:2, 16:9 or 9:16. FLUX 3 Klein takes a fixed set of sizes, so 4:5 and 3:2 come out at the nearest 4:3 shape.
Can FLUX 3 Klein edit an existing image?
Yes. Upload a reference image in the studio and describe the change, and Kinoseed sends it to FLUX 3 Klein's edit mode.
How many FLUX 3 Klein images can I make at once?
Up to 8 per run: choose 1, 2, 4 or 8. One image costs 3 credits and 8 cost 14.
Is there a FLUX 3 Klein API?
Yes. Send POST /api/v1/images with "model": "flux-3-klein" and an API key from your account page. The request on this page costs 3 credits (about $0.06), and POST /api/v1/quote prices any other settings before you spend anything. The same run is the generate_image tool on the Kinoseed MCP server.
Try FLUX 3 Klein on your own idea.
Plans from $10 a month, cancel anytime.