Generate images using Google's Nano Banana Pro (Gemini 3 Pro Image) model.
When to Use This Skill
| Use this skill when... |
Use imagemagick-conversion instead when... |
| Producing a brand-new image from a text prompt |
Converting, resizing, or compressing an existing image |
| Generating cinematic, product, or portrait artwork |
Building thumbnails or batch-processing many files |
| Mixing up to five reference images into a new render |
Applying deterministic transforms (rotate, crop, format) |
| Use this skill when... |
Use mermaid-diagrams or d2-diagrams instead when... |
| The output is a photographic or illustrative image |
The output is a flowchart, sequence, or architecture diagram |
| Quality settings (1K/2K/4K) and aspect ratio matter |
Diagram-as-code rendering would be more maintainable |
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
1---
2created: 2025-12-16
3modified: 2026-05-09
4reviewed: 2026-04-25
5description: "Image generation via Gemini 3 Pro Image: aspect ratio, resolution, reference images. Use when creating artwork, product photos, or mockups with AI."
6allowed-tools: Bash, Read, WebFetch
7model: sonnet
8args: <prompt> [--aspect <ratio>] [--resolution <size>] [--reference <path>]
9disable-model-invocation: true
10name: generate-image
11---
12
13Generate images using Google's Nano Banana Pro (Gemini 3 Pro Image) model.
14
15## When to Use This Skill
16
17| Use this skill when... | Use imagemagick-conversion instead when... |
18|---|---|
19| Producing a brand-new image from a text prompt | Converting, resizing, or compressing an existing image |
20| Generating cinematic, product, or portrait artwork | Building thumbnails or batch-processing many files |
21| Mixing up to five reference images into a new render | Applying deterministic transforms (rotate, crop, format) |
22
23| Use this skill when... | Use mermaid-diagrams or d2-diagrams instead when... |
24|---|---|
25| The output is a photographic or illustrative image | The output is a flowchart, sequence, or architecture diagram |
26| Quality settings (1K/2K/4K) and aspect ratio matter | Diagram-as-code rendering would be more maintainable |
27
28## Arguments
29
30- **{{arg:1}}** (required): Image description
31- **--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`
32- **--resolution**: Image resolution (`1K`, `2K`, `4K`) - default: `2K`
33- **--reference**: Path to reference image (repeatable, max 5)
34- **--output**: Custom output path
35
36## Environment Requirements
37
38Verify API key is set:
39```bash
40echo "API Key: ${GOOGLE_API_KEY:+SET}${GEMINI_API_KEY:+SET}"
41```
42
43If not set, get one from: https://aistudio.google.com/apikey
44
45## Usage Examples
46
47```
48/generate-image "A beautiful mountain landscape at sunset"
49/generate-image "Product photo on white background" --aspect 1:1 --resolution 4K
50/generate-image "Portrait photo" --aspect 3:4
51/generate-image "Cinematic scene" --aspect 21:9
52/generate-image "Similar style" --reference existing_image.png
53```
54
55## Task Workflow
56
571. **Parse arguments**:
58 - Extract prompt from {{arg:1}}
59 - Identify aspect ratio, resolution, and reference images
60
612. **Build command**:
62 ```bash
63 uv run python .claude/scripts/nano_banana_pro.py \
64 "{{arg:1}}" \
65 --aspect {{aspect|default:"16:9"}} \
66 --resolution {{resolution|default:"2K"}} \
67 {{reference_flags}}
68 ```
69
703. **Execute generation**:
71 ```bash
72 uv run python .claude/scripts/nano_banana_pro.py "PROMPT" --aspect RATIO --resolution SIZE
73 ```
74
754. **Report results**:
76 - Show path to generated image
77 - Note any reference images used
78 - Offer next steps (regenerate, different aspect, etc.)
79
80## Output
81
82Default output: `./generated/image_YYYYMMDD_HHMMSS.png`
83
84Custom output with `--output`:
85```
86/generate-image "Scene" --output custom_name.png
87```
88
89## Reference Images
90
91Reference images help maintain consistency:
92- Use existing images as style references
93- Keep subjects consistent across generations
94- Match artistic styles
95
96When using references, describe the relationship:
97- "Similar style to the reference"
98- "This person in a different setting"
99- "Same product, different angle"
100
101Maximum 5 reference images per generation.
102
103## Aspect Ratio Quick Reference
104
105| Use Case | Ratio |
106|----------|-------|
107| Square/Instagram | 1:1 |
108| Portrait | 3:4, 9:16 |
109| Landscape | 16:9 |
110| Ultrawide | 21:9 |
111| Photo | 3:2, 4:3 |
112
113## Resolution Quick Reference
114
115| Use Case | Resolution |
116|----------|------------|
117| Preview | 1K |
118| Standard | 2K |
119| High quality | 4K |
120
121## Error Handling
122
123- **No API key**: Set `GOOGLE_API_KEY` or `GEMINI_API_KEY`
124- **Generation failed**: Simplify prompt or reduce references
125- **Rate limited**: Wait and retry