imagegen2

name	imagegen2
description	Generate or edit game-oriented raster assets using OpenAI gpt-image-2 through the bundled zero-dependency CLI. Use for sprites, tiles, icons, portraits, UI assets, backgrounds, reference-image edits, and iterative visual variants saved into the project.

ImageGen2 for Gemini

The CLI is bundled next to this SKILL.md. Resolve it relative to the skill directory when installed. In this repository, the canonical development copy is also available at cli/generate.cjs.

node /path/to/imagegen2-skill/generate.cjs --prompt "..." --output "..." [options]

Recommended workflow:

1. Inspect the project for asset naming and directory conventions.
2. Choose a non-destructive output path.
3. Compose a prompt with style, subject, composition, palette, and constraints.
4. Run --dry-run for validation when using reference images or unusual sizes.
5. Run the CLI, parse JSON stdout, and report the saved path.

For transparent PNG sprites, prefer local chroma-key cleanup so generation stays on gpt-image-2:

--background transparent --transparent-mode chroma-key --chroma-key '#ff00ff'

Prompt for a solid flat key background with no shadows, gradients, or background objects. Local cleanup removes matching key pixels, alpha-bleeds hidden RGB in fully transparent pixels from nearby visible pixels, and can suppress strongly key-colored visible edge pixels when clean nearby subject colors are available. Disclose that this transparency comes from local chroma-key cleanup rather than native model alpha.

For true native alpha, use the explicit fallback:

--background transparent --transparent-mode fallback-model

This uses gpt-image-1.5; use it only when native alpha is required or chroma-key cleanup is unsuitable.

Reference images use repeatable --image <path> flags. Verify each path before invoking the CLI.