FLUX 3 Image

Use flux-3-image to create image output. This page contains the complete request needed for this model.

Model facts

Property	Value
Model ID	`flux-3-image`
Endpoint	`POST /api/v1/generation/create`
Output	Image
Modes	text-to-image, image-to-image
Pricing	View current pricing

Minimal request


curl -X POST https://api.api-stock.com/api/v1/generation/create \
  -H "Authorization: Bearer $API_STOCK_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "flux-3-image",
  "input": {
    "prompt": "A cinematic scene with soft natural light"
  }
}'

The create response contains a task ID:


{
  "code": 200,
  "data": {
    "taskId": "019ca881-9503-7270-a560-f00fc2b15785",
    "status": "not_started",
    "createdAt": "2026-08-22T12:00:00.000Z"
  }
}

Parameters

Parameters belong inside the top-level input object. Unknown fields are rejected.

Parameter	Type	Required	Default	Description
`prompt`	string	Yes	—	Text description or image editing instructions. Layout and bounding-box instructions may be included in the prompt.
`urls`	string[]	No	—	Reference image URLs for editing or multi-image guidance (up to 10 images). Omit for text-to-image generation.
`size`	“auto” \| “21:9” \| “2:1” \| “16:9” \| “3:2” \| “7:5” \| “4:3” \| “5:4” \| “1:1” \| “4:5” \| “3:4” \| “5:7” \| “2:3” \| “9:16” \| “1:2” \| “9:21”	No	`"auto"`	Image aspect ratio. Auto follows the first reference image, or the prompt when generating from text.
`resolution`	“768SQ” \| “1K” \| “1.5K” \| “2K” \| “4K”	No	`"1K"`	Output resolution tier; determines the per-image price.
`grounding`	boolean	No	`true`	Allow web and image search before generation. Reference images and search do not add a separate charge.

Modes

Minimal generation


{
  "model": "flux-3-image",
  "input": {
    "prompt": "A cinematic scene with soft natural light"
  }
}

With urls


{
  "model": "flux-3-image",
  "input": {
    "prompt": "A cinematic scene with soft natural light",
    "urls": [
      "https://example.com/input.jpg"
    ]
  }
}

Constraints

size: allowed: auto, 21:9, 2:1, 16:9, 3:2, 7:5, 4:3, 5:4, 1:1, 4:5, 3:4, 5:7, 2:3, 9:16, 1:2, 9:21.
resolution: allowed: 768SQ, 1K, 1.5K, 2K, 4K.

Invalid types, unsupported enum values, out-of-range numbers, and missing required fields return HTTP 400 with error.code: "invalid_input". Correct the request rather than retrying it unchanged.

Result

Poll the task or provide a top-level webhook URL in the create request:


curl https://api.api-stock.com/api/v1/task/status/$TASK_ID \
  -H "Authorization: Bearer $API_STOCK_KEY"

A successful media task returns one or more files:


{
  "code": 200,
  "data": {
    "taskId": "019ca881-9503-7270-a560-f00fc2b15785",
    "status": "finished",
    "files": [
      {
        "fileUrl": "https://s3.api-stock.com/result.png",
        "fileType": "image"
      }
    ],
    "createdTime": "2026-08-22T12:00:00.000Z"
  }
}

See Tasks and webhooks for terminal statuses, retries and webhook delivery.