# FLUX.2 Klein 4b (Async Image Generation)

> FLUX.2 Klein 4b (Async Image Generation) is a paid API for AI agents from fal.ai (queue) at fal-queue.mpp.tempo.xyz, paid per call via MPP, price unknown, status unknown (last checked 2026-10-30).

Asynchronously generates images using the FLUX.2 Klein 4b model via fal.ai's queue system, returning a request ID for polling.

## Facts

- Endpoint: POST https://fal-queue.mpp.tempo.xyz/fal-ai/flux-2/klein/4b?utm_source=zero.xyz
- Price: price unknown
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Provider: fal.ai (queue)
- Docs: https://fal.ai
- Website: https://fal.ai
- Tags: ai, media
- Canonical page: https://www.zero.xyz/c/fal-ai-queue-flux-2-klein-4b-async-image-generation-5212af9a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Wm-M0bpsC3DTJQspr-LWo

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability fal-ai-queue-flux-2-klein-4b-async-image-generation-5212af9a -d '<json body>'
```

Example prompt: Generate an image of a moonlit forest with fog rolling between ancient pine trees, photorealistic style — use the FLUX.2 Klein 4b async queue so it doesn't time out.

## When to prefer this

Choose this endpoint over fal.run (synchronous) when image generation is expected to exceed the ~100-second timeout threshold, or when you want to decouple submission from retrieval. Prefer the 4b variant over the 9b if you want a faster, lighter model at potentially lower cost. Use when you need the FLUX.2 Klein aesthetic specifically rather than FLUX.2 Pro or Seedream.

## Known failure modes

- Invalid or missing prompt — returns 400 error
- Dynamic pricing may fluctuate or be unavailable — pricing check required before call
- Queue overload may cause extended wait times before result is ready
- Polling timeout if agent does not retry with sufficient patience
- Unsupported parameter values may cause generation failure

## How this service works

FLUX.2 Klein 4b (dynamic pricing)

## Output

Returns a request_id immediately upon submission. The agent can then poll the fal queue's status endpoint with that request_id to retrieve the final generated image URL and metadata once processing completes. Polling is free.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fal-ai-queue-flux-2-klein-4b-async-image-generation-5212af9a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fal-queue.mpp.tempo.xyz](https://www.zero.xyz/host/fal-queue.mpp.tempo.xyz/llms.txt)