AI Image Generator
Generate images using AI APIs (Google Gemini and OpenAI GPT). This skill teaches the prompting patterns and API mechanics for producing professional images directly from Claude Code.
Managed alternative: If you don't want to manage API keys, ImageBot provides a managed image generation service with album templates and brand kit support.
Model Selection
Choose the right model for the job:
| Need | Model | Why |
|---|---|---|
| Photorealistic scenes / stock photos | Gemini 3.1 Flash Image | Best depth, complexity, environmental context |
| Final client scenes (higher detail) | Gemini 3 Pro Image | Higher detail, better style consistency |
| Text on images (posters, OG with copy, infographics) | GPT Image 2 | Text rendering actually works — including multi-script |
| 10-variation style exploration | GPT Image 2 | Native batch — one prompt, 10 variants sharing composition + palette |
| Multi-reference compositing (product + lifestyle) | GPT Image 2 | Handles lighting, scale, perspective across references |
| Transparent icons / logos | GPT Image 1.5 | Native RGBA alpha — GPT Image 2 cannot do transparency |
| Quick drafts / iteration | Gemini 2.5 Flash Image | Free tier (~500/day) |
Rule of thumb: any image with readable text → GPT Image 2 (unless you need transparency, then GPT 1.5). Otherwise → Gemini.
Model IDs
| Model | API ID | Provider |
|---|---|---|
| Gemini 3.1 Flash Image | gemini-3.1-flash-image-preview | Google AI |
| Gemini 3 Pro Image | gemini-3-pro-image-preview | Google AI |
| Gemini 2.5 Flash Image | gemini-2.5-flash-image | Google AI |
| GPT Image 2 (default) | gpt-image-2 | OpenAI |
| GPT Image 2 (ChatGPT-parity output) | chatgpt-image-latest | OpenAI |
| GPT Image 1.5 (transparency-only) | gpt-image-1.5 | OpenAI |
Verify model IDs before use — they change frequently:
curl -s "https://generativelanguage.googleapis.com/v1beta/models?key=$GEMINI_API_KEY" | python3 -c "import sys,json; [print(m['name']) for m in json.load(sys.stdin)['models'] if 'image' in m['name'].lower()]"
GPT Image 2 Specifics
Released 2026-04-22. Three capabilities that change when you'd reach for it.
1. Text rendering actually works
Posters, OG images with headlines, infographics with labels, UI mockups, pricing cards. Text is rendered reliably, including non-Latin scripts (Japanese, Korean, Hindi, Bengali). Primary reason to switch from Gemini — Gemini doesn't render readable text at all.
2. Multi-variation batching
One prompt, up to 10 images in a single call. Variants share composition and palette but differ in detail. Good for style exploration before committing, A/B options for a client, rapid ideation.
3. Multi-reference compositing
Feed reference images alongside your prompt — product shots, lifestyle scenes, logos. The model places the product into the scene with correct lighting, scale, perspective. Enables "product in context" workflows without multi-turn editing.
Modes
- Instant (default, all plans) — generates without a planning pass. Fast, good enough for most cases.
- Thinking (Plus/Pro/Business plans) — plans layout before drawing. Use when element counts matter ("3 icons in a row", "5 feature bullets") or text must land in specific regions. Fewer re-rolls on complex compositions.
Aspect ratios
3:1 ultra-wide through 1:3 ultra-tall, plus 1:1, 3:2, 2:3, 16:9, 9:16. Wider range than other models — useful for website banners (ultra-wide hero) or mobile story formats (ultra-tall).
Resolution
Up to 2K on the long edge standard. 4K in beta.
Generation time
Up to 2 minutes on complex prompts. Build async UX — don't block on the response. Show progress or spin off and poll.
Constraints
- No transparent backgrounds. Fall back to
gpt-image-1.5when you need PNG transparency. - API Org Verification may be required before the endpoint fires — enable in your OpenAI account settings if you hit auth errors on first call.
Pricing (per 1024×1024 image)
| Quality | Cost |
|---|---|
| Low | $0.006 |
| Medium | $0.053 |
| High | $0.211 |
Token pricing: $5/M text in, $10/M text out, $8/M image in, $30/M image out.
The 5-Part Prompting Framework
Build prompts in this order for consistent results:
1. Image Type
Set the genre: "A photorealistic photograph", "An isometric illustration", "A flat vector icon"
2. Subject
Who or what, with specific details: "of a warm, approachable Australian woman in her early 30s, smiling naturally"
3. Environment
Setting and spatial relationships: "in a bright modern home with terracotta decor on wooden shelves behind her"
4. Technical Specs
Camera and lighting: "Shot at 85mm f/2.0, natural window light, head and shoulders framing"
5. Constraints
What to exclude: "Photorealistic, no text, no watermarks, no logos"
Example (Good vs Bad)
BAD — keyword soup:
"professional woman, spa, warm lighting, high quality, 4K"
GOOD — narrative direction:
"A professional skin treatment scene in a warm clinical setting.
A practitioner wearing blue medical gloves uses a microneedling pen
on the client's forehead. The client lies on a white treatment bed,
eyes closed, relaxed. Warm golden-hour light from a window to the
left. Terracotta-toned wall visible in the background. Shot at
85mm f/2.0, shallow depth of field. No text, no watermarks."
Workflow
1. Determine Image Need
| Purpose | Aspect Ratio | Model |
|---|---|---|
| Hero banner (no text) | 16:9 or 21:9 | Gemini |
| Hero banner with headline copy | 16:9 or 3:1 ultra-wide | GPT Image 2 |
| Service card | 4:3 or 3:4 | Gemini |
| Profile / avatar | 1:1 | Gemini |
| Icon / badge (transparent) | 1:1 | GPT Image 1.5 |
| OG / social share (no text) | 1.91:1 | Gemini |
| OG / social share with copy | 1.91:1 | GPT Image 2 |
| Poster / infographic / pricing card / any typography-heavy | varies | GPT Image 2 |
| Style exploration (10 variants of one concept) | any | GPT Image 2 (batch) |
| Instagram post | 1:1 or 4:5 | Gemini |
| Mobile hero | 9:16 | Gemini |
2. Build the Prompt
Use the 5-part framework. Refer to references/prompting-guide.md for detailed photography parameters.
3. Generate via API
Gemini (Python — handles shell escaping correctly)
python3 << 'PYEOF'
import json, base64, urllib.request, os, sys
GEMINI_API_KEY = os.environ.get("GEMINI_API_KEY")
if not GEMINI_API_KEY:
print("Set GEMINI_API_KEY environment variable"); sys.exit(1)
model = "gemini-3.1-flash-image-preview"
url = f"https://generativelanguage.googleapis.com/v1beta/models/{model}:generateContent?key={GEMINI_API_KEY}"
prompt = """A professional photograph of a modern co-working space in
Newcastle, Australia. Natural light floods through floor-to-ceiling
windows. Three people collaborate at a standing desk — one pointing
at a laptop screen. Exposed brick wall, potted fiddle-leaf fig,
coffee cups on the desk. Shot at 35mm f/4.0, environmental portrait
style. No text, no watermarks, no logos."""
payload = json.dumps({
"contents": [{"parts": [{"text": prompt}]}],
"generationConfig": {
"responseModalities": ["TEXT", "IMAGE"],
"temperature": 0.8
}
}).encode()
req = urllib.request.Request(url, data=payload, headers={
"Content-Type": "application/json",
"User-Agent": "ImageGen/1.0"
})
resp = urllib.request.urlopen(req, timeout=120)
result = json.loads(resp.read())
# Extract image from response
for part in result["candidates"][0]["content"]["parts"]:
if "inlineData" in part:
img_data = base64.b64decode(part["inlineData"]["data"])
output_path = "hero-image.png"
with open(output_path, "wb") as f:
f.write(img_data)
print(f"Saved: {output_path} ({len(img_data):,} bytes)")
break
PYEOF