nanobanana

Nano Banana

A single Python entrypoint for Gemini-native Nano Banana image generation and editing, with model aliases, strict option validation, batch runs, and custom endpoint support.

Workflow

1. Open references/config.md to choose environment variables and override order.
2. Open references/models-and-api.md to pick the right Nano Banana tier and check model-specific constraints.
3. Prefer gemini-3.1-flash-image-preview (nanobanana-2) unless you need either the fastest low-cost default (nanobanana) or the highest-fidelity reasoning model (nanobanana-pro).
4. Run scripts/nanobanana.py generate for one request or scripts/nanobanana.py batch for repeated variants.
5. Add --dry-run first when the main risk is the payload shape, endpoint, or model-specific option support.
6. Pass --base-url or GEMINI_BASE_URL when you need a custom Gemini-compatible gateway.
7. Add --save-response <path> on generate when you need the raw JSON body for debugging.

Commands

Single text-to-image request:

python .\skills\nanobanana\scripts\nanobanana.py generate `
  --prompt "A retro-futurist product hero illustration for a developer tool" `
  --output .\out\hero.png `
  --model nanobanana-2 `
  --ratio 16:9 `
  --size 2K

Edit an existing image with two local references:

python .\skills\nanobanana\scripts\nanobanana.py generate `
  --prompt "Turn these references into a clean launch poster with legible title text" `
  --input-image .\refs\subject.png `
  --input-image .\refs\background.png `
  --output .\out\poster.png `
  --model nanobanana-pro `
  --ratio 4:5 `
  --size 2K

Use a custom Gemini-compatible gateway:

python .\skills\nanobanana\scripts\nanobanana.py generate `
  --prompt "A bold mascot sticker pack" `
  --output .\out\stickers.png `
  --base-url http://your-gateway.example.com/v1beta `
  --auth-mode bearer

Batch-generate five variants: