Permanent (User level)

[Environment]::SetEnvironmentVariable("GEMINI_API_KEY", "your-api-key-here", "User")


Or via Windows Settings:
- Search "Environment Variables" in Start Menu
- Click "Edit environment variables for your account"
- Add new variable: `GEMINI_API_KEY` with your API key

## Available Models

| Model | ID | Best For | Max Resolution |
|-------|-----|----------|----------------|
| **Flash** | `gemini-2.5-flash-image` | Speed, high-volume tasks | 1024px |
| **Pro** | `gemini-3-pro-image-preview` | Professional quality, complex scenes | Up to 4K |

## Image Generation Workflow

### Step 1: Generate the Image

Use `scripts/image.py` with uv:

```bash
uv run "${SKILL_DIR}/scripts/image.py" \
--prompt "Your image description" \
--output "/path/to/output.png"

Windows PowerShell:

uv run "$env:SKILL_DIR\scripts\image.py" `
  --prompt "Your image description" `
  --output "C:\path\to\output.png"

Options:

--prompt (required): Detailed description of the image to generate
--output (required): Output file path (PNG format)
--aspect (optional): Aspect ratio - "square", "landscape", "portrait" (default: square)
--reference (optional): Path to a reference image for style guidance
--model (optional): Model to use - "flash" (fast) or "pro" (high-quality) (default: flash)
--size (optional): Image resolution for pro model - "1K", "2K", "4K" (default: 1K)

Using Different Models

Flash model (default) - Fast generation:

uv run "${SKILL_DIR}/scripts/image.py" \
  --prompt "A minimalist logo design" \
  --output "/path/to/logo.png" \
  --model flash

Pro model - Higher quality:

uv run "${SKILL_DIR}/scripts/image.py" \
  --prompt "A detailed hero illustration" \
  --output "/path/to/hero.png" \
  --model pro \
  --size 2K

Crafting Effective Prompts

Write detailed, specific prompts for best results:

Good prompt:

A minimalist geometric pattern with overlapping translucent circles in coral, teal, and gold on a deep navy background, suitable for a modern fintech landing page hero section

Avoid vague prompts:

A nice background image

Prompt Elements to Include

Subject: What the image depicts
Style: Artistic style (minimalist, abstract, photorealistic, illustrated)
Colors: Specific color palette
Mood: Atmosphere (professional, playful, elegant, bold)
Context: How it will be used (hero image, icon, texture)

generate

Nano Banana Pro - Gemini Image Generation (Windows Compatible)

Prerequisites

Windows Setup