ModelFold - Image Upscale

Endpoint

POST /jobs/createTask

Full URL: https://modelfold.ai/v1/jobs/createTask

Authentication: every request must include the Authorization: Bearer <API_KEY> header.

Upscale an image by 1x, 2x, 4x, or 8x while keeping the original aspect ratio. Detail is restored generatively, and text regions are upscaled with a fidelity pass so the text is never rewritten.

upscale_factor multiplies both width and height. 1 enhances quality at the same size (denoise, sharpen, preserve text) without changing dimensions.

Input limits

Publicly downloadable HTTP(S) image URL
File size ≤ 20 MB
Formats: JPG, PNG, WEBP, GIF (first frame only)

Output limits

Output total pixels ≤ 67,108,864 (67 MP, about 8192×8192), and each side ≤ 16,384 px

Input	upscale_factor	Output	Output MP
1024×1024	`1`	1024×1024	1.05
1024×1024	`2` (default)	2048×2048	4.19
1024×1024	`4`	4096×4096	16.78
1024×1024	`8`	8192×8192	67.11
1646×1646	`8`	—	173 → 422

Output

Output width and height = input width and height × upscale_factor (exact integers, nothing is cropped)
Format follows the input: JPG → JPG, WEBP → WEBP, everything else → PNG. Transparent backgrounds are filled with white
Result URL expires after about 14 days — download and store it if you need it longer

Create Task

Submit with model=modelfold/image-upscale on the unified task endpoint.

Get Task Details — After submission, use the unified query endpoint to check task progress and retrieve results

TIP

For production use, we recommend providing the callBackUrl parameter so your service can receive completion notifications instead of polling for task status. Callbacks may be delivered more than once — deduplicate by taskId.

Market Overview — Explore all available models

Request Parameters

Body (application/json)

Parameter	Type	Required	Description
`model`	`string`	Yes	The model name to use for generation. Required field. - Must be `modelfold/image-upscale` for this endpoint Default：`"modelfold/image-upscale"`。 Allowed values：`modelfold/image-upscale`。 Example：`modelfold/image-upscale`。
`callBackUrl`	`string`	No	The URL to receive generation task completion updates. Optional but recommended for production use. - System will POST task status and results to this URL when generation completes - Callback includes generated content URLs and task information - Your callback endpoint should accept POST requests with JSON payload containing results - Alternatively, use the Get Task Details endpoint to poll task status - Callbacks may be delivered more than once — deduplicate by `taskId` - To ensure callback security, see Webhook Verification Guide for signature verification implementation Example：`https://your-domain.com/api/callback`。
`input`	`object`	Yes	Input parameters for the upscale task
`input.image_url`	`string`	Yes	URL of the image to upscale. Required. - Must be a publicly downloadable HTTP(S) URL - Max file size: 20 MB - Supported formats: JPG, PNG, WEBP, GIF (only the first frame is used) - Use a file URL after upload, not the file content itself Example：`https://static.aiquickdraw.com/tools/example/1794381136822_zlQCnA1z.jpg`。

Request Example

bash

curl -X POST "https://modelfold.ai/v1/jobs/createTask" \
  -H "Authorization: Bearer $MODELFOLD_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "modelfold/image-upscale",
  "callBackUrl": "https://your-domain.com/api/callback",
  "input": {
    "image_url": "https://static.aiquickdraw.com/tools/example/1794381136822_zlQCnA1z.jpg",
    "upscale_factor": "2"
  }
}'

python

import os
import requests

resp = requests.post(
    "https://modelfold.ai/v1/jobs/createTask",
    headers={
        "Authorization": "Bearer " + os.environ["MODELFOLD_API_KEY"],
        "Content-Type": "application/json",
    },
    json={
        "model": "modelfold/image-upscale",
        "callBackUrl": "https://your-domain.com/api/callback",
        "input": {
            "image_url": "https://static.aiquickdraw.com/tools/example/1794381136822_zlQCnA1z.jpg",
            "upscale_factor": "2",
        },
    },
)
print(resp.json())

javascript

const resp = await fetch("https://modelfold.ai/v1/jobs/createTask", {
  method: "POST",
  headers: {
    "Authorization": "Bearer " + process.env.MODELFOLD_API_KEY,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "model": "modelfold/image-upscale",
    "callBackUrl": "https://your-domain.com/api/callback",
    "input": {
      "image_url": "https://static.aiquickdraw.com/tools/example/1794381136822_zlQCnA1z.jpg",
      "upscale_factor": "2"
    }
  }),
});
console.log(await resp.json());

package main

import (
	"fmt"
	"io"
	"net/http"
	"os"
	"strings"
)

func main() {
	body := strings.NewReader(`{"model":"modelfold/image-upscale","callBackUrl":"https://your-domain.com/api/callback","input":{"image_url":"https://static.aiquickdraw.com/tools/example/1794381136822_zlQCnA1z.jpg","upscale_factor":"2"}}`)
	req, _ := http.NewRequest("POST", "https://modelfold.ai/v1/jobs/createTask", body)
	req.Header.Set("Authorization", "Bearer " + os.Getenv("MODELFOLD_API_KEY"))
	req.Header.Set("Content-Type", "application/json")
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer resp.Body.Close()
	out, _ := io.ReadAll(resp.Body)
	fmt.Println(string(out))
}

java

import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;

public class Main {
    public static void main(String[] args) throws Exception {
        String body = "{\"model\":\"modelfold/image-upscale\",\"callBackUrl\":\"https://your-domain.com/api/callback\",\"input\":{\"image_url\":\"https://static.aiquickdraw.com/tools/example/1794381136822_zlQCnA1z.jpg\",\"upscale_factor\":\"2\"}}";
        HttpRequest req = HttpRequest.newBuilder()
            .uri(URI.create("https://modelfold.ai/v1/jobs/createTask"))
            .header("Authorization", "Bearer " + System.getenv("MODELFOLD_API_KEY"))
            .header("Content-Type", "application/json")
            .method("POST", HttpRequest.BodyPublishers.ofString(body))
            .build();
        HttpResponse<String> resp = HttpClient.newHttpClient().send(req, HttpResponse.BodyHandlers.ofString());
        System.out.println(resp.body());
    }
}

php

<?php
$ch = curl_init('https://modelfold.ai/v1/jobs/createTask');
curl_setopt_array($ch, [
    CURLOPT_CUSTOMREQUEST => "POST",
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        'Authorization: Bearer ' . getenv("MODELFOLD_API_KEY"),
        'Content-Type: application/json',
    ],
    CURLOPT_POSTFIELDS => '{"model":"modelfold/image-upscale","callBackUrl":"https://your-domain.com/api/callback","input":{"image_url":"https://static.aiquickdraw.com/tools/example/1794381136822_zlQCnA1z.jpg","upscale_factor":"2"}}',
]);
echo curl_exec($ch);
curl_close($ch);

csharp

using System;
using System.Net.Http;
using System.Text;

var client = new HttpClient();
var req = new HttpRequestMessage(new HttpMethod("POST"), "https://modelfold.ai/v1/jobs/createTask");
req.Headers.TryAddWithoutValidation("Authorization", "Bearer " + Environment.GetEnvironmentVariable("MODELFOLD_API_KEY"));
req.Content = new StringContent("{\"model\":\"modelfold/image-upscale\",\"callBackUrl\":\"https://your-domain.com/api/callback\",\"input\":{\"image_url\":\"https://static.aiquickdraw.com/tools/example/1794381136822_zlQCnA1z.jpg\",\"upscale_factor\":\"2\"}}", Encoding.UTF8, "application/json");
var resp = await client.SendAsync(req);
Console.WriteLine(await resp.Content.ReadAsStringAsync());

json

{
  "model": "modelfold/image-upscale",
  "callBackUrl": "https://your-domain.com/api/callback",
  "input": {
    "image_url": "https://static.aiquickdraw.com/tools/example/1794381136822_zlQCnA1z.jpg",
    "upscale_factor": "2"
  }
}

Response

200 — Request successful

500 — Server error.

参数	类型	必填	说明
`code`	`integer`	是	See the response field; handle the returned status before retrying.
`msg`	`string`	是	Response message, error description when failed
`data`	`object`	是	—

json

{
  "code": 500,
  "msg": "Server Error - An unexpected error occurred while processing the request",
  "data": null
}

Callback

imageTaskCompleted

Callback URL: {request.body#/callBackUrl} (the callBackUrl in the request body).

The system sends this callback when the modelfold/image-upscale task succeeds or fails.

Callback body parameters

参数	类型	必填	说明
`code`	`integer`	是	Unified callback code: 200 for success, 501 for failure. Allowed values：`200` / `501`。 Example：`200`。
`msg`	`string`	是	Unified callback message. Allowed values：`Playground task completed successfully.` / `Playground task failed.`。 Example：`Playground task completed successfully.`。
`data`	`object`	是	—
`data.taskId`	`string`	是	The unique task identifier.
`data.model`	`string`	是	The model used for the task. Allowed values：`modelfold/image-upscale`。 Example：`modelfold/image-upscale`。
`data.state`	`string`	是	Terminal task state. Allowed values：`success` / `fail`。 Example：`success`。
`data.param`	`string`	是	JSON string containing the submitted task parameters.
`data.resultJson`	`string`	否	JSON string containing resultUrls when successful. Present only when state is success. Result URLs expire after about 14 days.
`data.failCode`	`string`	否	Failure code, a numeric string such as "400" or "500". Present only when state is fail.
`data.failMsg`	`string`	否	Failure reason. Present only when state is fail.
`data.costTime`	`integer`	否	Processing time in seconds. Present on both success and failure callbacks.
`data.completeTime`	`integer`	否	Task completion timestamp.
`data.createTime`	`integer`	否	Task creation timestamp.
`data.updateTime`	`integer`	否	Use completeTime as the completion time; updateTime may equal createTime.

Task completed successfully

json

{
  "code": 200,
  "msg": "Playground task completed successfully.",
  "data": {
    "taskId": "task_example_image_webhook_001",
    "model": "modelfold/image-upscale",
    "state": "success",
    "param": "{\"input\": \"{\\\"image_url\\\": \\\"https://example.com/input-image.png\\\", \\\"upscale_factor\\\": \\\"2\\\"}\", \"callBackUrl\": \"https://example.com/callback\", \"model\": \"modelfold/image-upscale\"}",
    "resultJson": "{\"resultUrls\": [\"https://example.com/upscaled-image.png\"]}",
    "costTime": 15,
    "completeTime": 1234567890,
    "createTime": 1234560000,
    "updateTime": 1234567890
  }
}

Task failed

json

{
  "code": 501,
  "msg": "Playground task failed.",
  "data": {
    "taskId": "task_example_image_webhook_001",
    "model": "modelfold/image-upscale",
    "state": "fail",
    "param": "{\"input\": \"{\\\"image_url\\\": \\\"https://example.com/input-image.png\\\", \\\"upscale_factor\\\": \\\"2\\\"}\", \"callBackUrl\": \"https://example.com/callback\", \"model\": \"modelfold/image-upscale\"}",
    "failCode": "400",
    "failMsg": "<error detail>",
    "costTime": 3
  }
}

ModelFold - Image Upscale ​

Endpoint ​

Input limits ​

Output limits ​

Output ​

Create Task ​

Related Resources ​

Request Parameters ​

Body (application/json) ​

Request Example ​

Response ​

200 — Request successful ​

500 — Server error. ​

Callback ​

imageTaskCompleted ​

ModelFold - Image Upscale

Endpoint

Input limits

Output limits

Output

Create Task

Related Resources

Request Parameters

Body (application/json)

Request Example

Response

200 — Request successful

500 — Server error.

Callback

imageTaskCompleted