generate-image Skill | Agent Skills

Generate images using Google's Nano Banana Pro (Gemini 3 Pro Image) model.

Arguments

{{arg:1}} (required): Image description
--aspect: Aspect ratio (1:1, 2:3, 3:2, 3:4, 4:3, 4:5, 5:4, 9:16, 16:9, 21:9) - default: 16:9
--resolution: Image resolution (1K, 2K, 4K) - default: 2K
--reference: Path to reference image (repeatable, max 5)
--output: Custom output path

Environment Requirements

Verify API key is set:

echo "API Key: ${GOOGLE_API_KEY:+SET}${GEMINI_API_KEY:+SET}"

If not set, get one from: https://aistudio.google.com/apikey

Usage Examples

/generate-image "A beautiful mountain landscape at sunset"
/generate-image "Product photo on white background" --aspect 1:1 --resolution 4K
/generate-image "Portrait photo" --aspect 3:4
/generate-image "Cinematic scene" --aspect 21:9
/generate-image "Similar style" --reference existing_image.png

Task Workflow

Parse arguments:
- Extract prompt from {{arg:1}}
- Identify aspect ratio, resolution, and reference images

Build command:

uv run python .claude/scripts/nano_banana_pro.py \
  "{{arg:1}}" \
  --aspect {{aspect|default:"16:9"}} \
  --resolution {{resolution|default:"2K"}} \
  {{reference_flags}}

Execute generation:

uv run python .claude/scripts/nano_banana_pro.py "PROMPT" --aspect RATIO --resolution SIZE

Report results:
- Show path to generated image
- Note any reference images used
- Offer next steps (regenerate, different aspect, etc.)

Output

Default output: ./generated/image_YYYYMMDD_HHMMSS.png

Custom output with --output:

/generate-image "Scene" --output custom_name.png

Reference Images

Reference images help maintain consistency:

Use existing images as style references
Keep subjects consistent across generations
Match artistic styles

When using references, describe the relationship:

"Similar style to the reference"
"This person in a different setting"
"Same product, different angle"

Maximum 5 reference images per generation.

Aspect Ratio Quick Reference

| Use Case | Ratio | |----------|-------| | Square/Instagram | 1:1 | | Portrait | 3:4, 9:16 | | Landscape | 16:9 | | Ultrawide | 21:9 | | Photo | 3:2, 4:3 |

Resolution Quick Reference

| Use Case | Resolution | |----------|------------| | Preview | 1K | | Standard | 2K | | High quality | 4K |

Error Handling

No API key: Set GOOGLE_API_KEY or GEMINI_API_KEY
Generation failed: Simplify prompt or reduce references
Rate limited: Wait and retry

Agent Skills: generate-image

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