gpt-image-2-api

gpt-image-2-api

Purpose

Generate and edit images with gpt-image-2 through a third-party OpenAI-compatible API using .env-configured OPENAI_API_KEY and OPENAI_BASE_URL values. Use when the user asks to create images, edit reference images, create visual assets, illustrations, or image variations with a configurable API endpoint.

Environment Variables & API Key

Two ways to configure API settings (priority: environment variable > .env):

1. Environment variables: OPENAI_API_KEY, OPENAI_BASE_URL, and optional OPENAI_IMAGE_* overrides
2. .env file: Place in .env, can copy from .env.example

You can manage the .env file manually or through skill-master env set.

Configuration

• OPENAI_API_KEY: API key for the third-party endpoint
• OPENAI_BASE_URL: OpenAI-compatible base URL, for example http://127.0.0.1:3688/v1
• OPENAI_IMAGE_MODEL: image model name, defaults to gpt-image-2
• OPENAI_IMAGE_PROTOCOL: openai_images or openai_chat, defaults to openai_images
• OPENAI_IMAGE_SIZE: image size, defaults to 1024x1024
• OPENAI_IMAGE_QUALITY: optional image quality
• OPENAI_IMAGE_N: number of images (1-10), defaults to 1
• OPENAI_IMAGE_OUTPUT_FORMAT: optional output format (png, jpeg, webp)
• OPENAI_IMAGE_FORMAT: legacy alias for OPENAI_IMAGE_OUTPUT_FORMAT
• OPENAI_IMAGE_RESPONSE_FORMAT: optional response format (url, b64_json)
• OPENAI_IMAGE_BACKGROUND: optional background (transparent, opaque, auto)
• OPENAI_IMAGE_MODERATION: optional moderation level (low, auto)
• OPENAI_IMAGE_OUTPUT_COMPRESSION: optional compression level 0–100 for jpeg / webp
• OPENAI_IMAGE_PARTIAL_IMAGES: optional streaming partial image count 0–3
• OPENAI_IMAGE_INPUT_FIDELITY: optional edit fidelity (high, low)
• OPENAI_IMAGE_STYLE: optional generation style for dall-e-3 (vivid, natural)
• OPENAI_IMAGE_STREAM: optional openai_images SSE toggle (true, false)
• OPENAI_IMAGE_USER: optional end-user identifier
• OPENAI_IMAGE_EXTRA_JSON: optional JSON object merged into the request body

Workflow

1. Use scripts/gpt-image-2-api.mjs for text-to-image and image-edit requests.
2. If required OPENAI_* settings are not available from the current environment or this skill's .env, stop and tell the user which variables need to be configured.
3. openai_images generation uses /images/generations with JSON; openai_images editing uses /images/edits with multipart/form-data.
4. Use OPENAI_IMAGE_PROTOCOL=openai_chat only when the endpoint lacks /images/* support; it does not support --mask, --background, --output-format, or streaming image events.
5. Add one or more --image <path> arguments to edit/reference an input image.
6. Use --mask <path> or --mask auto only with openai_images edits.
7. Save generated files under the user requested output directory, or the current working directory when unspecified.
8. Report saved file paths and any API errors exactly.

Available Scripts

• scripts/gpt-image-2-api.mjs — Sends a text prompt, optionally with input images, to the configured OpenAI-compatible endpoint and saves returned images.

Generate Image

node scripts/gpt-image-2-api.mjs --prompt "a concise image prompt" --output ./generated-images --size 1024x1024 --n 1 --output-format png

Use --base-url, --model, --protocol, --size, --quality, --n, --output-format, --background, --moderation, --response-format, and --extra-json only when the user or endpoint requires overrides.

Edit Image

node scripts/gpt-image-2-api.mjs --prompt "make the dog wear a red scarf" --image ./input.png --output ./edited-images

Multiple input images are supported by repeating --image. --input is accepted as an alias for --image.

Mask example for openai_images:

node scripts/gpt-image-2-api.mjs --protocol openai_images --prompt "replace the background" --image ./input.png --mask ./mask.png --output ./edited-images

Auto-mask example for openai_images:

node scripts/gpt-image-2-api.mjs --protocol openai_images --prompt "remove the background" --image ./input.png --mask auto --background transparent --output-format png --output ./edited-images

Fallback example when the endpoint only supports chat completions:

OPENAI_IMAGE_PROTOCOL=openai_chat node scripts/gpt-image-2-api.mjs --prompt "a concise image prompt" --output ./generated-images

Parameters

Parameter	Required	Type	Default	Description
prompt	yes	string	—	Text description for generation or edit
model	no	string	gpt-image-2	Image model name
n	no	integer	1	Number of images, range 1–10
size	no	string	1024x1024	Output size passed through to the upstream endpoint
quality	no	string	endpoint default	low, medium, high, auto
output-format	no	string	endpoint default	png, jpeg, webp
response-format	no	string	endpoint default	url, b64_json; mainly for DALL·E-compatible responses
background	no	string	endpoint default	transparent, opaque, auto
moderation	no	string	endpoint default	low, auto
output-compression	no	integer	endpoint default	Compression 0–100 for jpeg/webp
partial-images	no	integer	endpoint default	Streaming partial image count 0–3
input-fidelity	no	string	endpoint default	Edit fidelity: high, low
style	no	string	endpoint default	Generation style for dall-e-3: vivid, natural
user	no	string	—	End-user identifier
format	no	string	—	Legacy alias for output-format

Size Behavior

The script does not hard-validate size; values are passed through so OpenAI-compatible upstream endpoints can decide what they support.

For the Yunwu-compatible docs currently checked in this project:

• /images/generations documents auto, 1024x1024, 1536x1024, 1024x1536, 2048x2048, 2048x1152, 3840x2160, and 2160x3840
• /images/edits currently documents the classic GPT image set: auto, 1024x1024, 1536x1024, 1024x1536
• dall-e-2 documents 256x256, 512x512, 1024x1024
• dall-e-3 documents 1024x1024, 1792x1024, 1024x1792
• Chat-compatible fallbacks remain endpoint-specific

Because provider behavior may differ by endpoint and documentation may lag behind the implementation, this skill forwards size unchanged and lets the upstream API accept or reject it.

Size Constraints

1. Max side length ≤ 3840px
2. Both sides must be multiples of 16px
3. Aspect ratio ≤ 3:1 (long/short)
4. Total pixels: min 655360, max 8294400