POST/api/v1/imagine4 creditsAsynchronous

Flux Pro

Provider · Black Forest LabsType · T2IModel ID · flux-proUpstream ID · flux-pro (BFL direct)

Flux.1 Pro by Black Forest Labs. Highest quality Flux.1 model — premium photorealism and detail. Uses BFL direct API with polling. Asynchronous — the task must be polled or delivered via webhook.

Request Parameters

Parameter	Type	Required	Description
prompt	`string`	Required	The text prompt describing the image to generate.
model	`string`	Optional	Set to `flux-pro` to use this model.Default: `flux-pro`
aspect_ratio	`string`	Optional	Output aspect ratio. Allowed: 1:1 · 16:9 · 9:16 · 4:3 · 3:4 · 3:2 · 2:3.Default: `1:1`
negative_prompt	`string`	Optional	What to avoid in the generation. Max 4000 characters.
webhook_url	`string`	Optional	URL where we POST the completed task result.
webhook_secret	`string`	Optional	Sent as x-webhook-secret header in webhook delivery for verification.

Example Request

cURL

curl -X POST https://api.journeyapi.com/api/v1/imagine \
  -H "Authorization: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "flux-pro",
    "prompt": "a bioluminescent jellyfish in a dark ocean, high detail, cinematic",
    "aspect_ratio": "9:16",
    "output_format": "png",
    "webhook_url": "https://your-server.com/webhook"
  }'

Immediate Response

Returns immediately with a task ID. Poll /fetch or set a webhook_url to receive the result.

200 OK

{
  "task_id": "550e8400-e29b-41d4-a716-446655440000"
}

Quirks & Gotchas

Asynchronous: requires polling /fetch or a webhook. Returns task_id immediately.