generating-item-images - SKILL.md Agent Skill

name: Generating Item Images description: Generate AI-powered item images for Mystica game using Gemini with R2-hosted reference images. Use when creating item assets, generating game art, or when user mentions "item image", "generate image", "Mystica items", or "game assets".

Generating Item Images

Generate consistent AI-powered item images for Mystica using Gemini with style reference images.

Quick Start

npx tsx scripts/generate-image.ts \
  --type "ITEM_TYPE" \
  --materials "material1,material2" \
  --provider gemini \
  -r "https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/image-refs/IMG_0821.png,https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/image-refs/IMG_2791.png,https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/image-refs/IMG_4317.png,https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/image-refs/IMG_5508.png,https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/image-refs/IMG_9455.png"

Required Parameters

Parameter	Source	Example
`--type`	`docs/seed-data-items.json`	`"Gatling Gun"`, `"Umbrella"`
`--materials`	`docs/seed-data-materials.json`	`"cocaine,lava,plasma"` (1-3 materials)
`--provider`	Always `gemini`	`gemini`
`-r`	Always all 5 URLs below	See Quick Start

Optional Parameters

Parameter	Default	Purpose
`--aspect-ratio`	Auto	`"2:3"` for portrait items
`--format`	`png`	`jpg` for smaller files
`-o`	`scripts/output/gemini-{timestamp}.png`	Custom output path

Examples

Epic-tier weapon:

npx tsx scripts/generate-image.ts \
  --type "Gatling Gun" \
  --materials "cocaine,lava,plasma" \
  --provider gemini \
  -r "https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/image-refs/IMG_0821.png,https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/image-refs/IMG_2791.png,https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/image-refs/IMG_4317.png,https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/image-refs/IMG_5508.png,https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/image-refs/IMG_9455.png"

Output: scripts/output/gemini-{timestamp}.png → "Molten Vaporizer"

Uncommon utility item:

npx tsx scripts/generate-image.ts \
  --type "Umbrella" \
  --materials "bubble,slime" \
  --provider gemini \
  -r "https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/image-refs/IMG_0821.png,https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/image-refs/IMG_2791.png,https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/image-refs/IMG_4317.png,https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/image-refs/IMG_5508.png,https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/image-refs/IMG_9455.png"

Output: scripts/output/gemini-{timestamp}.png → "Slimebub Umbrella"

Material Reference

Common: coffee, gum, feather, button, candle, pizza Uncommon: matcha_powder, bubble, slime, propeller, magnet Rare: rainbow, lava, ghost, shadow, goo, cocaine, lube, void Epic: diamond, lightning, laser_beam, stardust, plasma

Complete list with stat modifiers: docs/seed-data-materials.json

Prerequisites

# Required in .env
REPLICATE_API_TOKEN=your_token
OPENAI_API_KEY=your_key

R2 bucket mystica-assets already configured at https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/

R2 Management

Quick Upload:

cd docs/image-refs

# Upload all images to R2 (remote)
for file in IMG_*.png; do
  wrangler r2 object put "mystica-assets/image-refs/$file" --file="$file" --remote
done

# Verify uploads
curl -I "https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/image-refs/IMG_0821.png"

Complete R2 Guide: See the Wrangler R2 Guide skill - Comprehensive Wrangler CLI reference with all bucket operations, CORS config, troubleshooting, and cost info.

Advanced Reference

R2 CLI Guide: Wrangler R2 Guide skill (complete Wrangler reference)
R2 Setup Details: docs/external/r2-image-hosting.md (integration guide)
Workflow Details: docs/ai-image-generation-workflow.md
Script Source: scripts/generate-image.ts
Description Generator: scripts/generate-item-description.ts