Model Guides/Image Models

GPT Image

POST

Overview

Use GPT Image through the unified image generation API. This guide covers the common text-to-image and edit parameters exposed by API Mall.

Authentication

All API requests require a Bearer token in the request header.

Authorization: Bearer YOUR_API_KEY

Create and manage API keys from API Keys or use https://www.apimall.ai/api-keys.

1. Create Generation Task

API Information

URL: POST https://gateway.apimall.ai/api/v1/images/generate
Content-Type: application/json

Request Parameters

Parameter	Type	Required	Description
`model`	string `gpt-image-1`	Required	Model identifier for this endpoint. Default: `gpt-image-1`
`type`	string `text-to-imageimage-to-image`	Optional	Task mode for the selected model. Default: `text-to-image`
`prompt`	string	Required	Prompt or edit instruction for the generation task.
`image_urls`	array	Optional	Reference image URLs for edit, upscale, or multi-image workflows.
`num_images`	integer	Optional	Number of output images to generate. Default: `1` Range: 1 - 6
`image_size`	string	Optional	Requested output size or provider-specific size preset.
`quality`	string `lowmediumhigh`	Optional	Quality tier used by GPT Image 1.5.
`background`	string `autotransparentopaque`	Optional	Background rendering mode for GPT Image 1.5.
`output_format`	string `jpegjpgpng`	Optional	Requested output image format.

Request Example

{
  "model": "gpt-image-1",
  "type": "text-to-image",
  "prompt": "A polished app icon featuring a glowing paper airplane.",
  "num_images": 1,
  "image_size": "1024x1024",
  "quality": "medium",
  "background": "auto",
  "output_format": "png"
}

Response Example

{
  "success": true,
  "data": {
    "task_id": "img_01HQ9M7XJQ7PZ3GQ9F6C5W3N2M",
    "request_id": "provider_req_01HQ9M87A5Y2QZW0S1R3T6YQ2C",
    "credits_used": 8,
    "remaining_credits": 112,
    "model": "gpt-image-1"
  },
  "request_id": "req_01HQ9M7J7X9P7Y8T6W5V4U3S2R"
}

cURL Example

curl --request POST 'https://gateway.apimall.ai/api/v1/images/generate' \
  --header 'Authorization: Bearer YOUR_API_KEY' \
  --header 'Content-Type: application/json' \
  --data '{
  "model": "gpt-image-1",
  "type": "text-to-image",
  "prompt": "A polished app icon featuring a glowing paper airplane.",
  "num_images": 1,
  "image_size": "1024x1024",
  "quality": "medium",
  "background": "auto",
  "output_format": "png"
}'

JavaScript Example

const API_KEY = process.env.APIMALL_API_KEY;
const CREATE_URL = 'https://gateway.apimall.ai/api/v1/images/generate';

const payload = {
  "model": "gpt-image-1",
  "type": "text-to-image",
  "prompt": "A polished app icon featuring a glowing paper airplane.",
  "num_images": 1,
  "image_size": "1024x1024",
  "quality": "medium",
  "background": "auto",
  "output_format": "png"
};

async function createTask() {
  const response = await fetch(CREATE_URL, {
    method: 'POST',
    headers: {
      Authorization: `Bearer ${API_KEY}`,
      'Content-Type': 'application/json',
    },
    body: JSON.stringify(payload),
  });

  if (!response.ok) {
    throw new Error(`Create task failed: ${response.status} ${response.statusText}`);
  }

  const json = await response.json();
  const taskId = json.data?.task_id;

  if (!taskId) {
    throw new Error('Missing task_id in create response');
  }

  return taskId;
}

async function getTask(taskId) {
  const response = await fetch(`https://gateway.apimall.ai/api/v1/images/${encodeURIComponent(String(taskId))}`, {
    headers: {
      Authorization: `Bearer ${API_KEY}`,
    },
  });

  if (!response.ok) {
    throw new Error(`Query task failed: ${response.status} ${response.statusText}`);
  }

  const json = await response.json();
  return {
    ...json,
  };
}

async function waitForTask(taskId) {
  while (true) {
    const task = await getTask(taskId);
    const state = task.data?.status;

    if (state === 'completed') {
      return task;
    }

    if (state === 'failed') {
      throw new Error(task.data?.failMsg || 'Task failed');
    }

    await new Promise((resolve) => setTimeout(resolve, 3000));
  }
}

(async () => {
  const taskId = await createTask();
  const result = await waitForTask(taskId);
  console.log(result);
})().catch(console.error);

Response Parameters

Parameter	Type	Description
`success`	boolean	Whether the request completed successfully.
`data.task_id`	string	Task ID used to query task status and results.
`data.request_id`	string	Provider-side request identifier for tracing.
`data.credits_used`	integer	Credits consumed by this request.
`data.remaining_credits`	integer	Credits remaining after the request.
`data.model`	string	Model name used for the task.
`request_id`	string	Request identifier for debugging and support.

Error Response Example

{
  "success": false,
  "error": {
    "code": "insufficient_credits",
    "message": "Insufficient credits"
  },
  "request_id": "req_01HQ9M7J7X9P7Y8T6W5V4U3S2R"
}

2. Query Task Status

API Information

URL: GET https://gateway.apimall.ai/api/v1/images/{task_id}

Path Parameters

Parameter	Type	Required	Description
`task_id`	string	Required	Image task identifier returned by `POST /api/v1/images/generate`.

Request Example

GET https://gateway.apimall.ai/api/v1/images/img_01HQ9M7XJQ7PZ3GQ9F6C5W3N2M

cURL Example

curl --request GET 'https://gateway.apimall.ai/api/v1/images/img_01HQ9M7XJQ7PZ3GQ9F6C5W3N2M' \
  --header 'Authorization: Bearer YOUR_API_KEY'

Response Example

{
  "success": true,
  "data": {
    "task_id": "img_01HQ9M7XJQ7PZ3GQ9F6C5W3N2M",
    "model": "gpt-image-1",
    "status": "completed",
    "output": {
      "resultUrls": [
        "https://cdn.apimall.ai/generated/image-01.webp"
      ]
    },
    "primary_url": "https://cdn.apimall.ai/generated/result.webp",
    "image_url": "https://cdn.apimall.ai/generated/cover.webp",
    "error_message": null,
    "credits_used": 8,
    "credits_refunded": 0,
    "created_at": "2026-03-12T09:30:00.000Z",
    "updated_at": "2026-03-12T09:31:06.000Z",
    "completed_at": "2026-03-12T09:31:06.000Z"
  },
  "request_id": "req_01HQ9M7J7X9P7Y8T6W5V4U3S2R"
}

Response Parameters

Parameter	Type	Description
`success`	boolean	Whether the request completed successfully.
`data.task_id`	string	Task ID used to query task status and results.
`data.model`	string	Model name used for the task.
`data.status`	string	Current status value returned by the API. Generation task endpoints use normalized values such as `pending`, `processing`, `completed`, `failed`, or `unknown`; management endpoints may return resource states such as `created`, `revoked`, or `active`.
`data.output.resultUrls`	array	Generated result URLs returned by the upstream provider payload.
`data.primary_url`	string	Primary hosted image URL for image tasks.
`data.image_url`	string	Hosted image result URL.
`data.error_message`	string	Failure reason returned when the music task does not complete successfully.
`data.credits_used`	integer	Credits consumed by this request.
`data.credits_refunded`	integer	Credits refunded after failure or partial refund handling.
`data.created_at`	string	Creation timestamp for the returned resource or task record.
`data.updated_at`	string	Last update timestamp for the returned resource or task record.
`data.completed_at`	string	Completion timestamp for the task when available.
`request_id`	string	Request identifier for debugging and support.

Usage Flow

Create a generation task by calling `POST https://gateway.apimall.ai/api/v1/images/generate`.
Persist `data.task_id` from the create response so you can resume polling later.
Poll `GET https://gateway.apimall.ai/api/v1/images/{task_id}` until `data.status` reaches `completed` or `failed`.
Read the generated image URLs from the final task payload.

Integration Notes

Store your API key on the server side only.
Persist the returned `data.task_id` immediately so you can resume polling after restarts.
Use an `Idempotency-Key` header when retrying create requests from your backend.
Poll the task endpoint every few seconds with backoff until `data.status` reaches `completed` or `failed`.
Use `data.primary_url` or `data.image_url` as the final hosted asset URL.

Error Codes

Common Error Codes

Status Code	Description
200	Request successful
400	Invalid request parameters
401	API key required or invalid API key
402	Insufficient credits
403	API access not approved or request made on a non-gateway host
409	Idempotency-Key conflict
429	Rate limit exceeded or too many concurrent jobs
503	Upstream provider is busy or temporarily unavailable
451	Prompt blocked by content moderation
500	Internal server error

Request

curl --location --request POST 'https://gateway.apimall.ai/api/v1/images/generate' \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data-raw '{
  "model": "gpt-image-1",
  "type": "text-to-image",
  "prompt": "A polished app icon featuring a glowing paper airplane.",
  "num_images": 1,
  "image_size": "1024x1024",
  "quality": "medium",
  "background": "auto",
  "output_format": "png"
}'

{
  "success": true,
  "data": {
    "task_id": "img_01HQ9M7XJQ7PZ3GQ9F6C5W3N2M",
    "request_id": "provider_req_01HQ9M87A5Y2QZW0S1R3T6YQ2C",
    "credits_used": 8,
    "remaining_credits": 112,
    "model": "gpt-image-1"
  },
  "request_id": "req_01HQ9M7J7X9P7Y8T6W5V4U3S2R"
}