FLUX 1.1 Pro

POST /v1/tasks

All models are called through the Unified Async API POST /v1/tasks endpoint; only the input fields differ (see input parameters below).

Model summary

Model name	flux-1.1-pro
Type	Image generation
Endpoint	POST /v1/tasks
Pricing	See HiAPI Pricing

FLUX 1.1 Pro is suited to photorealistic images, commercial posters, product shots, and optional reference guidance.

Production guidance

For production, pass callback.url at the top level of the request body so HiAPI can notify your service when the task reaches a terminal state.
GET /v1/tasks/:id is better for local debugging, low-volume jobs, or fallback reconciliation if a callback is missed.
Use callback.when=final. Both success and fail are terminal states, so your service should deduplicate by taskId.

Best suited for

Photorealistic products

Product, still-life, and commercial visuals with a photographic feel.

promptaspect_ratio

Reference guidance

Use image_prompt to guide the result from an existing asset.

image_prompt

Custom dimensions

Select custom and specify width and height.

aspect_ratiowidthheight

Output quality control

Tune format and quality for handoff.

output_formatoutput_quality

Request parameters

POST https://api.hiapi.ai/v1/tasks

# Create an async task — returns taskId immediately (generation runs async)
# Replace YOUR_API_KEY with your account API key
curl -X POST "https://api.hiapi.ai/v1/tasks" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "flux-1.1-pro",
  "input": {
    "prompt": "A small red apple on a white table",
    "aspect_ratio": "1:1",
    "output_format": "webp",
    "output_quality": 80,
    "prompt_upsampling": false,
    "safety_tolerance": 2
  }
}'

import requests, json

# Business params — fields vary by model (see the model page)
payload = json.loads(r'''
{
  "model": "flux-1.1-pro",
  "input": {
    "prompt": "A small red apple on a white table",
    "aspect_ratio": "1:1",
    "output_format": "webp",
    "output_quality": 80,
    "prompt_upsampling": false,
    "safety_tolerance": 2
  }
}
''')

# Create an async task — returns taskId immediately (generation runs async)
resp = requests.post(
    "https://api.hiapi.ai/v1/tasks",
    headers={"Authorization": "Bearer YOUR_API_KEY", "Content-Type": "application/json"},
    json=payload,
)
print(resp.json())  # Returns { code, message, data: { taskId } }

// Create an async task — returns taskId immediately (generation runs async)
// Replace YOUR_API_KEY with your account API key
const resp = await fetch("https://api.hiapi.ai/v1/tasks", {
  method: "POST",
  headers: {
    "Authorization": "Bearer YOUR_API_KEY",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
  "model": "flux-1.1-pro",
  "input": {
    "prompt": "A small red apple on a white table",
    "aspect_ratio": "1:1",
    "output_format": "webp",
    "output_quality": 80,
    "prompt_upsampling": false,
    "safety_tolerance": 2
  }
}),
});
console.log(await resp.json()); // Returns { code, message, data: { taskId } }

model string required

Fixed value flux-1.1-pro.

example flux-1.1-pro

input object required

Business parameters for photorealistic image control.

prompt string required

Image generation prompt.

image_prompt string optional

Optional reference image URL. Supports jpeg, png, gif, and webp. SVG is not supported.

aspect_ratio enum optional

Output image ratio. Use custom to drive width and height.

default 1:1 enum: custom1:116:93:22:34:55:49:163:44:3

width integer optional

Custom width, only used when aspect_ratio=custom. Range 256-1440.

height integer optional

Custom height, only used when aspect_ratio=custom. Range 256-1440.

safety_tolerance integer optional

Safety tolerance. 1 is strictest and 6 is most permissive.

default 2

seed integer optional

Random seed for reproducible generation.

prompt_upsampling boolean optional

Whether to automatically enhance the prompt.

default false

output_format enum optional

Output format.

default webp enum: webpjpgpng

output_quality integer optional

Output quality, 0-100. Not relevant for png.

default 80

callback object optional

Optional callback configuration. In production, pass callback.url so HiAPI can notify your service when the task reaches a terminal state.

url string required

HTTPS URL that receives terminal task notifications.

example https://your-domain.com/hiapi/callback

when enum optional

Callback trigger timing. Use final for terminal-state notifications.

default final enum: final

Example requests

Basic photorealistic image

Product or still-life image generation.

Request body

{
  "model": "flux-1.1-pro",
  "input": {
    "prompt": "A small red apple on a white table",
    "aspect_ratio": "1:1",
    "output_format": "webp",
    "output_quality": 80,
    "prompt_upsampling": false,
    "safety_tolerance": 2
  }
}