GPT Image 2 API

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

Image, video, and audio 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	gpt-image-2/text-to-image
Type	Image generation (text-to-image)
Routes	default / beta / ext
Endpoint	POST /v1/tasks
Model & Playground	GPT Image 2 model page
Pricing guide	GPT Image 2 API pricing and cost per image

Send model=gpt-image-2/text-to-image to POST /v1/tasks to call GPT Image 2. This reference covers every request field, route difference, callback, polling step, and code example.

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.

API key and pricing

Create a HiAPI API key before calling GPT Image 2, and keep the key on your server.
This page documents request fields and code. Use the dedicated pricing guide linked in Model summary for current per-image rates, route differences, and batch budgets; do not hard-code prices in your app.
For prompt validation, start with 1K output. Increase resolution or switch to a higher-fidelity model only for final assets.

Best suited for

Accurate text rendering

Useful for menus, signs, UI screenshots, infographics, and any image where text must stay readable.

promptresolution

Poster and layout work

Use one detailed prompt to describe headlines, supporting copy, subject placement, and whitespace.

promptaspect_ratioresolution

Product and commerce images

Generate clean product visuals with consistent composition for product pages and social covers.

promptaspect_ratio

Long-prompt creative drafts

Control subject, style, material, camera, composition, and text content in one complex prompt.

prompt

Multi-format delivery

Adapt one creative direction into square, landscape, portrait, or ultrawide placements.

aspect_ratioresolution

Multiple routes

The beta route controls output via a size field; ext unlocks multi-ratio 4K. Each route is priced differently.

route

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": "gpt-image-2/text-to-image",
  "input": {
    "prompt": "A clean product photo of a red apple on a white table",
    "aspect_ratio": "1:1",
    "resolution": "1K"
  },
  "callback": {
    "url": "https://your-domain.com/hiapi/callback",
    "when": "final"
  }
}'

import requests, json

# Business params — fields vary by model (see the model page)
payload = json.loads(r'''
{
  "model": "gpt-image-2/text-to-image",
  "input": {
    "prompt": "A clean product photo of a red apple on a white table",
    "aspect_ratio": "1:1",
    "resolution": "1K"
  },
  "callback": {
    "url": "https://your-domain.com/hiapi/callback",
    "when": "final"
  }
}
''')

# 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": "gpt-image-2/text-to-image",
  "input": {
    "prompt": "A clean product photo of a red apple on a white table",
    "aspect_ratio": "1:1",
    "resolution": "1K"
  },
  "callback": {
    "url": "https://your-domain.com/hiapi/callback",
    "when": "final"
  }
}),
});
console.log(await resp.json()); // Returns { code, message, data: { taskId } }

Route

Default route: full 1K/2K/4K resolutions and 16 aspect ratios (including auto), one flat rate per image.

model string required

Fixed value gpt-image-2/text-to-image.

example gpt-image-2/text-to-image

route string optional

Omit for the default route, or pass default explicitly.

example default

input object required

Business parameters. GPT Image 2 model-specific configuration lives here.

prompt string required

Text prompt, up to 20000 characters.

aspect_ratio enum optional

Aspect ratio of the generated image. Default auto. Note: 5:4, 4:5, 3:1, 1:3, and 9:21 support 1K images only.

default auto enum: auto1:13:22:34:33:45:44:516:99:16 +6

resolution enum optional

Image resolution. Note: 1:1 cannot be generated at 4K; auto or an unspecified aspect ratio can only be generated at 1K.

default 1K enum: 1K2K4K

callback object optional

Optional callback configuration. HiAPI sends a terminal notification to your service when the task finishes.

url string required

Required when callback is provided. HTTPS URL that receives the terminal task notification.

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

when enum optional

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

default final enum: final

The beta route has a different parameter shape: a size field replaces aspect_ratio and resolution. Pass route: "beta" at the top level.

model string required

Fixed value gpt-image-2/text-to-image, combined with route to select the beta route.

example gpt-image-2/text-to-image

route string required

Fixed value beta.

example beta

input object required

Business parameters.

prompt string required

Text prompt, up to 20000 characters.

size string optional

Output size, replacing aspect_ratio and resolution. Default auto lets the model decide; a width x height pixel value is also accepted.

default auto example 1024x1024

callback object optional

Optional callback configuration. HiAPI sends a terminal notification to your service when the task finishes.

url string required

Required when callback is provided. HTTPS URL that receives the terminal task notification.

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

when enum optional

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

default final enum: final

The ext multi-ratio 4K route: all 16 aspect ratios available at 1K/2K/4K, resolution and quality are required, priced by quality tier. Pass route: "ext" at the top level.

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": "gpt-image-2/text-to-image",
  "route": "ext",
  "input": {
    "prompt": "A clean product photo of a red apple on a white table",
    "aspect_ratio": "1:1",
    "resolution": "1K",
    "quality": "low"
  }
}'

import requests, json

# Business params — fields vary by model (see the model page)
payload = json.loads(r'''
{
  "model": "gpt-image-2/text-to-image",
  "route": "ext",
  "input": {
    "prompt": "A clean product photo of a red apple on a white table",
    "aspect_ratio": "1:1",
    "resolution": "1K",
    "quality": "low"
  }
}
''')

# 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": "gpt-image-2/text-to-image",
  "route": "ext",
  "input": {
    "prompt": "A clean product photo of a red apple on a white table",
    "aspect_ratio": "1:1",
    "resolution": "1K",
    "quality": "low"
  }
}),
});
console.log(await resp.json()); // Returns { code, message, data: { taskId } }

model string required

Fixed value gpt-image-2/text-to-image, combined with route to select the ext route.

example gpt-image-2/text-to-image

route string required

Fixed value ext.

example ext

input object required

Business parameters.

prompt string required

Text prompt, up to 20000 characters.

aspect_ratio enum optional

Output aspect ratio; all 16 ratios are available at every resolution tier (including 5:4, 4:5, 2:1, etc.).

default 1:1 enum: auto1:13:22:34:33:45:44:516:99:16 +6

resolution enum required

Resolution tier: 1K ≈ 1024px, 2K ≈ 2048px, 4K up to 3840×2160; actual pixels vary by ratio.

default 1K enum: 1K2K4K

quality enum required

Quality tier, affects pricing: low is clean and sharp for volume, medium adds visible detail, high is cinematic.

default low enum: lowmediumhigh

callback object optional

Optional callback configuration. HiAPI sends a terminal notification to your service when the task finishes.

url string required

Required when callback is provided. HTTPS URL that receives the terminal task notification.

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 text-to-image

Minimum usable request with prompt, aspect ratio, and resolution.

Request body

{
  "model": "gpt-image-2/text-to-image",
  "input": {
    "prompt": "A clean product photo of a red apple on a white table",
    "aspect_ratio": "1:1",
    "resolution": "1K"
  }
}

Square product creative

For product pages, social avatars, and square cover placements.

Request body

{
  "model": "gpt-image-2/text-to-image",
  "input": {
    "prompt": "A premium skincare bottle on a white acrylic surface, soft studio lighting, clean commercial product photography",
    "aspect_ratio": "1:1",
    "resolution": "1K"
  }
}

Portrait poster with text

Put the required words, hierarchy, and layout constraints directly into the prompt.

Request body

{
  "model": "gpt-image-2/text-to-image",
  "input": {
    "prompt": "A vertical launch poster with the exact headline \"SUMMER DROP\", small subtitle \"New arrivals\", bright product photography, clean grid layout, generous whitespace",
    "aspect_ratio": "9:16",
    "resolution": "1K"
  }
}

Production request with callback

Recommended production shape: create the task, then wait for callback.url to receive the terminal notification.

Request body

{
  "model": "gpt-image-2/text-to-image",
  "input": {
    "prompt": "A clean product photo of a red apple on a white table",
    "aspect_ratio": "1:1",
    "resolution": "1K"
  },
  "callback": {
    "url": "https://your-domain.com/hiapi/callback",
    "when": "final"
  }
}

Getting the result

The response returns a taskId immediately without waiting for generation to finish.
In production, prefer waiting for callback.url to receive the terminal notification. For local debugging, poll GET /v1/tasks/:id.
When status=success, download the generated image from output[].url.
When status=fail, fix the request based on the returned error instead of retrying the same invalid payload.

FAQ

What is the GPT Image 2 API?

GPT Image 2 is HiAPI’s text-to-image generation API for product visuals, posters, and text-heavy layouts. You call it through the unified POST /v1/tasks endpoint with model gpt-image-2/text-to-image; it returns a taskId immediately, and you fetch the result by polling or callback.

How do I get an API key for GPT Image 2?

Create a key in the HiAPI dashboard under API keys and send it as a Bearer token in the request header. Keep the key on your server, not in client-side code. Create an API key

How much does the GPT Image 2 API cost?

The standard route uses a fixed per-image price for the selected resolution; other routes and specifications may differ. This page keeps the request contract, while the dedicated guide linked in Model summary covers current rates, batch budgets, and billing details.

Can GPT Image 2 render text inside images?

Yes. GPT Image 2 is strong at accurate text rendering for menus, posters, signage, infographics, and UI mockups — put the exact words and layout requirements directly in the prompt.

Which routes does gpt-image-2/text-to-image offer, and how do the parameters differ?

Three routes. Standard: aspect_ratio (including auto) plus resolution (1K/2K/4K). Beta: a different parameter shape — a size field replaces aspect_ratio and resolution. Ext: a multi-ratio 4K route (quality and resolution required) — see the ext tab under request parameters. Route prices may differ; use the pricing guide linked in Model summary for current costs.

How do I call the beta or ext route?

Pass the base model name with a top-level route parameter, e.g. route: 'beta', or spell the route into the model name, e.g. gpt-image-2/text-to-image@beta — the two are equivalent. Note that input parameters differ per route, so adjust the fields accordingly.

GPT Image 2 API

Model summary

Production guidance

Best suited for

Request parameters

Example requests

Getting the result

FAQ

What is the GPT Image 2 API?

How do I get an API key for GPT Image 2?

How much does the GPT Image 2 API cost?

Can GPT Image 2 render text inside images?

Which routes does gpt-image-2/text-to-image offer, and how do the parameters differ?

How do I call the beta or ext route?

Next steps