Enhance the resolution and quality of generated images using advanced AI upscaling technology.

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Endpoint

POST https://api.legnext.ai/api/v1/upscale

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Headers

HeaderTypeRequiredDescription
x-api-keystringYesYour API key

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Request Body

ParameterTypeRequiredDescription
jobIdstringYesID of the original image generation task
imageNointegerYesImage number to upscale (0/1/2/3)
typeintegerYesUpscaling type (0 or 1)
callbackstringNoCallback URL for task completion notifications

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Upscale Types

TypeNameDescriptionSupported Models
0SubtleConservative enhancement preserving original detailsv6, niji6, v6.1, v7
1CreativeMore aggressive enhancement with artistic interpretationv6, niji6, v6.1, v7
22x2x resolution increase (deprecated)v5, niji5
34x4x resolution increase (deprecated)v5, niji5

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Example Requests

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Subtle Upscale

curl -X POST "https://api.legnext.ai/api/v1/upscale" \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "jobId": "5dd94ec3-7282-4f04-9445-59e850ef1822",
    "imageNo": 0,
    "type": 0,
    "callback": "https://webhook.site/c98cb890-fb92-439f-8d60-42c8a51eb52d"
  }'

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Creative Upscale

curl -X POST "https://api.legnext.ai/api/v1/upscale" \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "jobId": "5dd94ec3-7282-4f04-9445-59e850ef1822",
    "imageNo": 0,
    "type": 1,
    "callback": "https://webhook.site/c98cb890-fb92-439f-8d60-42c8a51eb52d"
  }'

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Response

Returns a task object containing the task information. 
{
    "job_id": "98761286-cdc7-4085-abfe-c9f149ff722b",
    "model": "midjourney",
    "task_type": "upscale",
    "status": "completed",
    "config": {
        "service_mode": "public",
        "webhook_config": {
            "endpoint": "https://webhook.site/d0ca59bc-35a6-4a1e-b1b1-aea7faeb7f67",
            "secret": ""
        }
    },
    "input": null,
    "output": {
        "image_url": "https://image.legnext.ai/20250922/01k5qp2gqrfef8761r8n9q9w0c_0_0.png?Expires=1761102268&Signature=iNZM9BV0OCS32GXCSYEruuCs7zU%3D",
        "image_urls": [
            "https://image.legnext.ai/20250922/01k5qp2gqrfef8761r8n9q9w0c_0_0.png?Expires=1761102268&Signature=iNZM9BV0OCS32GXCSYEruuCs7zU%3D"
        ]
    },
    "meta": {
        "created_at": "2025-09-22T03:04:27Z",
        "started_at": "2025-09-22T03:04:28Z",
        "ended_at": "2025-09-22T03:05:03Z",
        "usage": {
            "type": "point",
            "frozen": 00,
            "consume": 00
        }
    },
    "detail": null,
    "logs": [],
    "error": {
        "code": 0,
        "raw_message": "",
        "message": "",
        "detail": null
    }
}

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Upscale Types Comparison

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Subtle (Type 0)

  • Best For: Photography, realistic images, preserving original details
  • Characteristics:
    • Minimal artistic interpretation
    • Preserves original composition and style
    • Clean, sharp enhancement
    • Suitable for professional use

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Creative (Type 1)

  • Best For: Artistic images, illustrations, creative projects
  • Characteristics:
    • Enhanced artistic details
    • More dramatic improvement
    • May add creative interpretation
    • Good for artistic workflows