image-gen

name	image-gen
description	Use when generating image files from text prompts with the local Gemini image CLI. Trigger this when the user asks to create, generate, or render an AI image, artwork, ad image, book cover, mockup, visual asset, or says to use image-gen from the terminal. This skill runs the global `image-gen` executable from any repo.

Image Generation (Gemini)

Generate images from text prompts using Google Gemini via the global image-gen CLI.

Command

Run from any directory:

image-gen "your prompt here" [options]

Prompt is a positional argument, not a flag.

Requirements

The CLI uses GEMINI_API_KEY if it is set. If not, it automatically reads the key from macOS Keychain item gemini-api-key for account $USER.

Add the key to Keychain with:

security add-generic-password -U -a "$USER" -s gemini-api-key -w "YOUR_GEMINI_API_KEY"

If neither source exists, the CLI prints these setup instructions and exits.

Options

Flag	Short	Default	Description
--output-dir	-o	.	Output directory
--aspect-ratio	-a	1:1	Aspect ratio
--resolution	-r	1K	Resolution
--width		None	Target width for resize
--height		None	Target height for resize

Valid Aspect Ratios

1:1, 2:3, 3:2, 3:4, 4:3, 4:5, 5:4, 9:16, 16:9, 21:9

Valid Resolutions

1K, 2K, 4K

These are named tiers, not pixel dimensions. Do not use 1024x1024 or similar.

Resize

Pass both --width and --height together to resize the output. Both are required for resize to take effect.

Examples

# Basic generation
image-gen "a golden retriever puppy in autumn leaves"

# Widescreen, highest resolution, saved to output/
image-gen "mountain landscape at sunset" -a 16:9 -r 4K -o output

# Portrait with resize
image-gen "fashion portrait" -a 3:4 -r 2K --width 900 --height 1200

After Running

The command outputs a timestamp filename, such as 2026-02-14T10-30-45.png. Rename it to something descriptive based on the prompt, such as golden-retriever-autumn.png.

Common Mistakes

• Using --prompt instead of a positional argument.
• Using pixel dimensions like 1024x1024 for resolution. Use 1K, 2K, or 4K.
• Running repo-local image commands from another project.
• Forgetting that --width and --height must both be provided.