Upscale generated images

October 3, 2025

Table of contents

  1. Request Headers
  2. Request Body
  3. Responses
  4. Model
  5. Examples
  6. Try It

This endpoint upscales previously generated images to higher resolution.

https://api.useapi.net/v1/ltxstudio/images/upscale

Request Headers 
Authorization: Bearer {API token}
Content-Type: application/json
# Alternatively you can use multipart/form-data
# Content-Type: multipart/form-data
Request Body 
{
  "jobId": "email:[email protected]:7a34b821-9fd0-205e-d21b-4abc6f7839e7-type:image"
}
  • email is optional when only one account configured. However, if you have multiple accounts configured, this parameter becomes required.
  • jobId is required, the job ID from a previously completed image generation job. Use the jobId field from POST images/edit or POST images/create response.
  • pollForResult is optional, number of polling attempts to wait for completion (each attempt waits 3 seconds, up to 60 seconds total max) before sending job to the scheduler. For example, pollForResult: 5 will poll every 3 seconds for up to 15 seconds total.
    Supported values: 1-20.
    Default: immediate return with jobId.
  • maxJobs is optional, override the default maximum number of concurrent jobs.
  • replyUrl is optional, webhook URL for job completion notifications. See GET assets/jobId for response model.
  • replyRef is optional, custom reference for webhook identification.
Responses

  • 200 OK (Job Created)

    {
    "jobId": "email:[email protected]:8b45c932-0fe1-316f-e32c-5bcd7g8940f8-type:image",
    "generationId": "gen_xyz789abc012"
}

  • 200 OK (pollForResult completed)

    {
    "status": {
        "type": "completed",
        "progress": 100,
        "artifact": {
            "assetUrl": "https://storage.googleapis.com/lt-infinity-prd/artifacts/vertex-ai/…",
            "expirationDateString": "1748919477350",
            "asset": {
                "type": "artifact",
                "fileId": "asset:4c29…-type:image/png",
                "mimeType": "image/png",
                "artifactSubtype": "vertex-ai"
            }
        }
    },
    "jobId": "email:[email protected]:8b45c932-0fe1-316f-e32c-5bcd7g8940f8-type:image",
    "replyRef": "custom-reference-123",
    "replyUrl": "https://webhook.example.com/ltx-callback",
    "code": 200
}

  • 400 Bad Request

    {
  "error": "Error message",
  "code": 400
}

  • 401 Unauthorized

    {
  "error": "Unauthorized",
  "code": 401
}

  • 402 Payment Required

    {
  "error": "Insufficient credits",
  "code": 402
}
Model

Use GET assets/jobId to retrieve job status and results if they were not provided with the response.

{ // TypeScript, all fields are optional
    status: {
        type: 'active' | 'completed' | 'failed'
        progress?: number
        message?: string
        artifact?: {
            assetUrl: string
            expirationDateString: string
            asset: {
                type: string
                fileId: string
                mimeType: string
                artifactSubtype: string
            }
        }
    }
    jobId?: string
    generationId?: string
    replyRef?: string
    replyUrl?: string
    code?: number
}
Examples 
  • curl "https://api.useapi.net/v1/ltxstudio/images/upscale" \
   -H "Authorization: Bearer …" \
   -H "Content-Type: application/json" \
   -d '{
     "jobId": "email:[email protected]:7a34b821-9fd0-205e-d21b-4abc6f7839e7-type:image",
     "pollForResult": 10
   }'

  • const token = "API token";
const apiUrl = "https://api.useapi.net/v1/ltxstudio/images/upscale";

const response = await fetch(apiUrl, {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${token}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "jobId": "email:[email protected]:7a34b821-9fd0-205e-d21b-4abc6f7839e7-type:image",
    "pollForResult": 10
  })
});
const result = await response.json();
console.log("response", {response, result});

  • import requests
token = "API token"
apiUrl = "https://api.useapi.net/v1/ltxstudio/images/upscale"
headers = {
    "Authorization" : f"Bearer {token}",
    "Content-Type": "application/json"
}
data = {
    "jobId": "email:[email protected]:7a34b821-9fd0-205e-d21b-4abc6f7839e7-type:image",
    "pollForResult": 10
}
response = requests.post(apiUrl, headers=headers, json=data)
print(response, response.json())
Try It