GPT Image 1.5 - Image Generation & Editing

Generate new images or edit existing ones using OpenAI's GPT Image 1.5 model.

Generation: Uses the Responses API with image_generation tool
Editing: Uses the Image API for reliable mask-based inpainting

Usage

Run the script using absolute path (do NOT cd to skill directory first):

Generate new image:

uv run ~/.claude/skills/gpt-image-1-5/scripts/generate_image.py --prompt "your image description" --filename "output-name.png" [--quality low|medium|high] [--size 1024x1024|1024x1536|1536x1024|auto] [--background transparent|opaque|auto] [--api-key KEY]

Edit existing image (without mask - full image edit):

uv run ~/.claude/skills/gpt-image-1-5/scripts/generate_image.py --prompt "editing instructions" --filename "output-name.png" --input-image "path/to/input.png" [--size 1024x1024|1024x1536|1536x1024|auto] [--api-key KEY]

Edit existing image (with mask - precise inpainting):

uv run ~/.claude/skills/gpt-image-1-5/scripts/generate_image.py --prompt "what to put in masked area" --filename "output-name.png" --input-image "path/to/input.png" --mask "path/to/mask.png" [--size 1024x1024|1024x1536|1536x1024|auto] [--api-key KEY]

Important: Always run from the user's current working directory so images are saved where the user is working, not in the skill directory.

Parameters

Quality Options

low - Fastest generation, lower quality
medium (default) - Balanced quality and speed
high - Best quality, slower generation

Map user requests:

No mention of quality -> medium
"quick", "fast", "draft" -> low
"high quality", "best", "detailed", "high-res" -> high

Size Options

1024x1024 (default) - Square format
1024x1536 - Portrait format
1536x1024 - Landscape format
auto - Let the model decide based on prompt

Map user requests:

No mention of size -> 1024x1024
"square" -> 1024x1024
"portrait", "vertical", "tall" -> 1024x1536
"landscape", "horizontal", "wide" -> 1536x1024

Background Options (generation only)

auto (default) - Model decides
transparent - Transparent background (PNG/WebP output)
opaque - Solid background

API Key

The script checks for API key in this order:

--api-key argument (use if user provided key in chat)
OPENAI_API_KEY environment variable

If neither is available, the script exits with an error message.

Filename Generation

Generate filenames with the pattern: yyyy-mm-dd-hh-mm-ss-name.png

Format: {timestamp}-{descriptive-name}.png

Timestamp: Current date/time in format yyyy-mm-dd-hh-mm-ss (24-hour format)
Name: Descriptive lowercase text with hyphens
Keep the descriptive part concise (1-5 words typically)
Use context from user's prompt or conversation
If unclear, use random identifier (e.g., x9k2, a7b3)

Examples:

Prompt "A serene Japanese garden" -> 2025-12-17-14-23-05-japanese-garden.png
Prompt "sunset over mountains" -> 2025-12-17-15-30-12-sunset-mountains.png
Prompt "create an image of a robot" -> 2025-12-17-16-45-33-robot.png
Unclear context -> 2025-12-17-17-12-48-x9k2.png

Image Editing

Both editing modes use the Image API (images.edit endpoint) with gpt-image-1.5 for reliable results.

Without Mask (Full Image Edit)

When the user wants to modify an existing image without specifying exact regions:

Use --input-image parameter with the path to the image
The prompt should contain editing instructions (e.g., "make the sky more dramatic", "change to cartoon style")
A fully transparent mask is auto-generated, allowing the model to edit the entire image

With Mask (Precise Inpainting)

When the user wants to edit specific regions:

Use --input-image parameter with the path to the image
Use --mask parameter with a PNG mask file
The mask should have transparent areas (alpha=0) where edits should occur
The prompt describes what should appear in the masked region

Common editing tasks: add/remove elements, change style, adjust colors, replace backgrounds, etc.

Prompt Handling

For generation: Pass user's image description as-is to --prompt. Only rework if clearly insufficient.

For editing: Pass editing instructions in --prompt (e.g., "add a rainbow in the sky", "make it look like a watercolor painting")

Preserve user's creative intent in both cases.

Output

Saves PNG to current directory (or specified path if filename includes directory)
Script outputs the full path to the generated image
Do not read the image back - just inform the user of the saved path

Examples

Generate new image:

uv run ~/.claude/skills/gpt-image-1-5/scripts/generate_image.py --prompt "A serene Japanese garden with cherry blossoms" --filename "2025-12-17-14-23-05-japanese-garden.png" --quality high --size 1536x1024

Generate with transparent background:

uv run ~/.claude/skills/gpt-image-1-5/scripts/generate_image.py --prompt "A cute cartoon cat mascot" --filename "2025-12-17-14-25-30-cat-mascot.png" --background transparent --quality high

Edit existing image (full image):

uv run ~/.claude/skills/gpt-image-1-5/scripts/generate_image.py --prompt "make the sky more dramatic with storm clouds" --filename "2025-12-17-14-27-00-dramatic-sky.png" --input-image "original-photo.jpg"

Edit with mask (inpainting):

uv run ~/.claude/skills/gpt-image-1-5/scripts/generate_image.py --prompt "a flamingo swimming" --filename "2025-12-17-14-30-00-lounge-flamingo.png" --input-image "lounge.png" --mask "mask.png"