> ## Documentation Index > Fetch the complete documentation index at: https://docs.modellix.ai/llms.txt > Use this file to discover all available pages before exploring further. # GPT Image 1.5 Edit > [Core Function] GPT Image 1.5 Edit is a versatile image-to-image editing and merging model. [Strengths] It excels at complex utility editing tasks, including multi-image merging (up to 16 images), transparent background support, and precise control over how strictly the model adheres to the input image (fidelity control). [Best For] Highly recommended for: merging reference images, editing UI assets, generating variations with strict shape preservation, and creating transparent cutouts. [Limitations] Do NOT use this model if you require 2K or 4K high-resolution outputs, as it is limited to standard resolutions. [Routing] Use this model specifically when the user provides multiple images to combine, requires transparency, or explicitly asks to 'keep the exact shape' of the original image (fidelity control). Otherwise, use GPT Image 2 Edit. ## OpenAPI ````yaml /model-api/openai/openai-i2i.json post /openai/gpt-image-1.5-edit openapi: 3.1.0 info: description: The image-to-image (image editing) models API from OpenAI. version: 1.0.0 contact: name: Modellix Support email: support@modellix.ai title: OpenAI Image-to-Image Models API servers: - url: https://api.modellix.ai/api/v1 description: The image-to-image models API from OpenAI. security: - bearerAuth: [] paths: /openai/gpt-image-1.5-edit: post: tags: - GPT Image Edit summary: GPT Image 1.5 Edit description: >- [Core Function] GPT Image 1.5 Edit is a versatile image-to-image editing and merging model. [Strengths] It excels at complex utility editing tasks, including multi-image merging (up to 16 images), transparent background support, and precise control over how strictly the model adheres to the input image (fidelity control). [Best For] Highly recommended for: merging reference images, editing UI assets, generating variations with strict shape preservation, and creating transparent cutouts. [Limitations] Do NOT use this model if you require 2K or 4K high-resolution outputs, as it is limited to standard resolutions. [Routing] Use this model specifically when the user provides multiple images to combine, requires transparency, or explicitly asks to 'keep the exact shape' of the original image (fidelity control). Otherwise, use GPT Image 2 Edit. operationId: gptImage15EditAsync requestBody: description: Request payload for standard GPT Image Edit models. required: true content: application/json: schema: $ref: '#/components/schemas/StandardGPTImageEditRequest' examples: basic: summary: Basic image editing value: images: - image_url: https://example.com/input.png prompt: Convert to vintage style transparent: summary: Generate transparent background value: images: - file_id: file-abc123 prompt: Remove background, keep only the main subject background: transparent multi_image: summary: Multi-image merge editing value: images: - image_url: https://example.com/image1.png - image_url: https://example.com/image2.png - image_url: https://example.com/image3.png prompt: Merge these images into a cohesive collage responses: '200': description: Task submitted successfully content: application/json: schema: $ref: '#/components/schemas/AsyncTaskResponse' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '429': $ref: '#/components/responses/TooManyRequests' '500': $ref: '#/components/responses/InternalServerError' components: schemas: StandardGPTImageEditRequest: description: Request payload for standard GPT Image Edit models. type: object required: - images - prompt properties: prompt: type: string description: Description of the desired edits, supports up to 32,000 characters minLength: 1 maxLength: 32000 example: Add a watercolor effect to this image images: type: array description: >- Input image URL(s) to edit. Direct HTTPS URLs as string array. Supports up to 16 images for GPT Image models minItems: 1 maxItems: 16 items: type: string description: Direct image URL (https only) example: https://example.com/image.png example: - https://example.com/input.png size: type: string description: Output image size. Preset resolutions only default: 1024x1024 enum: - 1024x1024 - 1536x1024 - 1024x1536 example: 1024x1024 quality: type: string description: >- Output quality level. 'low': fast draft (default), 'medium': balanced, 'high': best quality default: low enum: - low - medium - high example: high background: type: string description: >- Background transparency. 'transparent': transparent background (requires png or webp format), 'opaque': solid background, 'auto': model decides default: auto enum: - transparent - opaque - auto example: transparent input_fidelity: type: string description: >- Control fidelity to original input image. 'high': preserve original details, 'low': more creative freedom enum: - high - low example: high mask: type: string description: >- Optional mask URL. Must be PNG with alpha channel; dimensions must match the input image exactly. Transparent areas are edited, opaque areas locked, semi-transparent areas blend with the original. example: https://example.com/mask.png AsyncTaskResponse: description: Response object for asynchronous task submission. type: object required: - code - message - data properties: code: type: integer description: Response code, 0 indicates success example: 0 message: type: string description: Response message example: success data: description: Detailed data about the submitted asynchronous task. type: object required: - status - task_id - model_id properties: status: type: string description: Task status enum: - pending - processing - completed - failed example: pending task_id: type: string description: Unique task identifier for status polling example: task_abc123xyz model_id: type: string description: Model identifier used for this task example: gpt-image-2-edit ErrorResponse: description: Standard error response object. type: object required: - code - message properties: code: type: integer description: Error code example: 400 message: type: string description: Error message example: Invalid request parameters details: type: object description: Additional error details additionalProperties: true responses: BadRequest: description: Invalid request parameters content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' Unauthorized: description: Authentication required or invalid content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' TooManyRequests: description: Rate limit exceeded content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' InternalServerError: description: Internal server error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: JWT ````