Black Forest Labs

Flux 2 klein

Image

Fastest FLUX.2 model for rapid iteration and low-latency applications

from $0.01 / call Flux 2 klein API reference →
Model health Insufficient data
curl -X POST https://runapi.ai/api/v1/flux/text_to_image \
  -H "Authorization: Bearer $RUNAPI_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "flux-2-klein",
  "prompt": "Generate a 4K product hero image of a matte-black water bottle on a beige stone surface, soft side light."
}'
https://runapi.ai 1 endpoint

3 versions available

Playground

Try Flux 2 klein

Pick any model and generate in seconds.

Estimated: $0.01 / image

Sign in to generate with RunAPI.

Sign in to generate

Sign in to start generating with your available language models.

Specifications

Technical details

Provider Black Forest Labs
Model ID flux-2-klein
Modality Image
Task types Asynchronous
API endpoint /api/v1/flux/text_to_image
Billing unit call
Input parameters aspect_ratio, output_count, prompt
Aspect ratios 1:1, 4:3, 3:4, 16:9, 9:16, 3:2, 2:3
Catalog status Operational
HOW IT WORKS

Use This Model in 3 Steps

  1. Get Your Key

    Sign up for free and create an API key for flux-2-klein from the dashboard.

  2. Send a Request

    POST to /api/v1/flux/text_to_image with the flux-2-klein model slug and your parameters.

  3. Get Results

    Poll the task or follow the callback to retrieve the completed flux-2-klein result.

What this model offers

Flexible parameters

Configure 3 documented parameters, including aspect_ratio, output_count, prompt.

Endpoint coverage

Exposes 1 public endpoint(s): text_to_image.

Usage-based billing

Metered by call with no subscription requirement.

Flux 2 klein Pricing

Endpoint
Resolution
Duration
Price
text_to_image
Not available
call
$0.01 / image
API REFERENCE

Endpoint Specification

Endpoint
POST /api/v1/flux/text_to_image
Model ID
flux-2-klein
Task Types
text_to_image
Max Duration
Unavailable
Resolutions
Unavailable
Aspect Ratios
1:1, 4:3, 3:4, 16:9, 9:16, 3:2, 2:3
Output Format
Unavailable
Avg Generation Time
Unavailable

Request parameters

prompt

Required string

No description available.

aspect_ratio

Optional value

No description available. (1:1, 4:3, 3:4, 16:9, 9:16, 3:2, 2:3)

output_count

Optional integer

No description available. (1)

USE CASES

Product photography

Auto-generate lifestyle product photos for e-commerce catalogs that lack studio photography.

Game & concept art

Rapidly concept environments and characters before committing to final art.

Editorial illustration

Generate unique cover art and illustrations for blog posts and articles at scale.

FAQ

Frequently asked questions about Flux 2 klein

How do I select flux-2-klein?

Pass the model ID shown in the quickstart.

What's the rate limit on this variant?

Per-key rate limits scale with your usage tier. The pricing page shows current limits. If you need higher throughput, contact support to discuss tier upgrades.

Can I switch variants later?

Yes. Variant is a parameter in the request. Switch by changing the model ID — no code changes, no re-authentication, no separate billing setup. All variants share the same API key and request shape.

Does it stream?

Where streaming is available, RunAPI streams end-to-end. LLM models support token-level streaming. Media models use async task polling or webhook callbacks for result delivery.

Where do I report quality issues?

Open an issue on the public GitHub repo or email support at [email protected]. Include the task ID and model ID so the team can investigate the specific generation.

Do I need a separate provider account?

No. Your RunAPI API key is enough to access this variant and every other model in the catalog. You do not need accounts with the underlying provider.

Building with a team?

We're here to help with enterprise setup, integrations, and technical questions.

Contact Us