ImageStableFLUX

FLUX.2 Klein 4B

black-forest-labs/flux-2-klein-4b

Image gen

Pricing

Input / 1M tokens: $0
Output / 1M tokens: $0
Example workload: $0 · 1M in + 250K out

Metered from your APIRaven balance. Normalized usage ships in every response.

Call it from any OpenAI SDK

Use the official SDK with a custom base URL. The example below is complete — swap the model id to hit a different model in the catalog.

curl https://api.apiraven.com/v1/images/generations \
  -H "Authorization: Bearer $APIRAVEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "black-forest-labs/flux-2-klein-4b",
    "prompt": "an isometric raven reading a rate card, studio light",
    "size": "1024x1024",
    "n": 1,
    "response_format": "url"
  }'

POST /v1/images/generations

Standardized parameters

Parameters behave the same on every backend. Values that cannot be honored are either mapped to the closest equivalent or safely dropped — never silently corrupted.

Parameter	Type	Default	Range	Status
Core
`prompt`	string	—	—	Supported
`n` Number of images per request.	integer	1	1 – 4	Supported
`size` Available sizes are listed on each model page.	enum	1024×1024	—	Supported
Quality
`steps` Higher is slower and more detailed.	integer	model default	1 – 50	Supported
`guidance_scale` Prompt adherence vs. creative freedom.	number	model default	1 – 20	Supported
`negative_prompt` Where the backend supports negative prompts.	string	—	—	Supported
`seed`	integer	random	—	Supported
Output
`response_format`	enum	url	url \| b64_json	Supported

Using FLUX.2 Klein 4B on APIRaven

Which provider actually runs my request?+

APIRaven routes each request across a pool of managed inference backends. The model id, request shape and response are identical no matter which backend serves it — you never manage provider accounts, keys or regions.

Is the API OpenAI-compatible?+

Yes. Point any OpenAI SDK at https://api.apiraven.com/v1 with your APIRaven key. Chat, vision, images, embeddings and audio all follow the OpenAI request and response shapes.

What happens when a backend degrades?+

Requests are retried and failed over automatically before the first token is returned. If a model is temporarily unavailable, the API returns one stable error envelope instead of a provider-specific failure.

How is usage billed?+

Per token for text, per image for generation and per minute for transcription — deducted from your APIRaven balance. Every response includes normalized usage so you can meter cost per request.

Ship with black-forest-labs/flux-2-klein-4b

One base URL, one balance, every model. Point your OpenAI SDK at APIRaven and switch models with a single string.

Get your API key