Flux 2 API — AI Image Generation API | Photorealistic, Free Credits

Provider

Black Forest Labs

Pricing

6–20 credits per image (~$0.012–$0.04)

Speed

3–8 seconds

Output

image

Quick Start

Send a request to the Flux 2 API:

bash

curl -X POST https://apiin.one/api/v1/images/generations \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "flux-2",
  "prompt": "A serene Japanese garden with cherry blossoms, koi pond, and wooden bridge, photorealistic",
  "aspect_ratio": "16:9",
  "type": "pro",
  "resolution": "1K"
}'

API Endpoint

POST/api/v1/images/generationsFlux 2

Send a POST request with your API key to generate content using Flux 2.

Headers

Header	Type	Requis	Description
`Authorization`	string	Requis	Bearer YOUR_API_KEY
`Content-Type`	string	Requis	application/json

Body Parameters

Paramètre	Type	Requis	Description
`model`	string	Requis	Model identifier: "flux-2"
`prompt`	string	Requis	Text description of the image (3–5000 chars)
`aspect_ratio`	string	Optionnel	Output aspect ratio (e.g. 1:1, 16:9, 9:16) (Par défaut : 1:1)
`type`	string	Optionnel	Generation mode: "pro" (higher quality) or "flex" (faster/cheaper) (Par défaut : pro)
`resolution`	string	Optionnel	Output resolution: "1K" or "2K" (Par défaut : 1K)
`input_urls`	array	Optionnel	Array of image URLs for image-to-image (max 8 images)

Example Request

json

{
  "model": "flux-2",
  "prompt": "A serene Japanese garden with cherry blossoms, koi pond, and wooden bridge, photorealistic",
  "aspect_ratio": "16:9",
  "type": "pro",
  "resolution": "1K"
}

Example Response

Successful task creation response.

{
  "code": 200,
  "message": "success",
  "data": {
    "task_id": "n41xxxx_flux2",
    "status": "IN_PROGRESS"
  }
}

Check Task Status

For asynchronous tasks, poll the status endpoint to check when your task is complete:

GET/api/v1/tasks/{task_id}Poll task status

Returns the current status of a generation task. Poll until status is 'completed' or 'failed'.

bash

curl https://apiin.one/api/v1/tasks/task_abc123 \
  -H "Authorization: Bearer aio_your_key"

Use Cases

✓Generate product mockups and marketing visuals from text descriptions
✓Create AI-generated artwork and illustrations for content
✓Build AI image generation features into your application
✓Produce photorealistic stock images on demand

API Tester

Test the Flux 2 API directly from your browser:

Aire de jeux APIPOST

URL de base

Point de terminaison

En-têtes

Corps de la requête

Error Codes

{
  "error": {
    "code": 400,
    "message": "Invalid parameters",
    "type": "invalid_request"
  }
}

Frequently Asked Questions

How much does the Flux 2 API cost?

Credits vary by mode and resolution. Pro mode at 1K costs ~10 credits, 2K costs ~20 credits. Flex mode at 1K costs ~6 credits. Free credits included on sign up.

What is the difference between Pro and Flex mode?

Pro mode produces higher quality results. Flex mode is faster and cheaper, suitable for rapid iteration. Set the "type" parameter to "pro" or "flex".

Can I use reference images?

Yes. Flux 2 supports image-to-image by providing up to 8 input image URLs via the "input_urls" parameter alongside your text prompt.

What resolutions are supported?

Flux 2 supports 1K and 2K resolution output. Set via the "resolution" parameter.

Is the Flux 2 API compatible with OpenAI?

Yes. API in One uses an OpenAI-compatible REST format. If you're already using the OpenAI Images API, switching to Flux 2 requires minimal code changes.