Nano Banana Pro

Google · Gemini 3 Pro Image

nano-banana-pro-ext

More stable than Banana 2, better for finals. Stronger text and complex layouts, native 4K, a bit slower.

Text-to-imageImage-to-imageImage edit

Get API key Official docs

Output

Completed images appear here after a successful Credit debit.

API

Call Nano Banana Pro

ImgRouter uses one request contract. Send this model ID to POST /v1/images/generations. Examples below match the recommended defaults on this page.

POST/v1/images/generations

cURL

curl https://api.imgrouter.com/v1/images/generations \
  -H "Authorization: Bearer $IMGROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: nano-banana-pro-ext-generate-001" \
  -d '{
  "model": "nano-banana-pro-ext",
  "prompt": "A cozy coffee shop interior with warm lighting, wooden tables, and plants by the window on a rainy afternoon.",
  "size": "16:9",
  "resolution": "2K",
  "n": 1
}'

Request body

Parameters and usage notes

These are the ImgRouter fields. Official upstream names such as image_urls are mapped from reference_images.

modelstring · requiredDefault and required: nano-banana-pro-ext.

promptstring · requiredText instruction, 1–5,000 characters. Describe the image or the edit you want.

sizestring · default 16:9Aspect ratio. Supported: auto, 1:1, 2:3, 3:2, 3:4, 4:3, 4:5, 5:4, 9:16, 16:9, 21:9. Prefer an explicit ratio instead of auto when you need predictable framing.

resolutionstring · default 2KOutput tier. Supported: 1K, 2K, 4K. Higher tiers cost more Credits.

ninteger · 1–1Number of output images. Send a number, not a quoted string. Defaults to 1 and cannot exceed 1.

reference_imagesstring[] · max 14Public HTTPS image URLs for image-to-image or edit. Send this field to POST /v1/images/edits. Official docs may call this image_urls.

Controls

Size, resolution, and output

Aspect ratio or size

auto1:12:33:23:44:34:55:49:1616:921:9

Resolution

1K2K4K

Output format

url

Route notes

Professional generation and editing route with up to fourteen references.

One image is generated per request.

4K requests take longer; use 1K or 2K during iteration.

Reference workflow

Edit with reference images

Send public HTTPS source images with the same core controls. This route accepts up to 14 reference images.

POST/v1/images/edits

cURL

curl https://api.imgrouter.com/v1/images/edits \
  -H "Authorization: Bearer $IMGROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: nano-banana-pro-ext-edit-001" \
  -d '{
  "model": "nano-banana-pro-ext",
  "prompt": "Preserve the subject and composition. Change the scene to soft blue hour.",
  "size": "16:9",
  "resolution": "2K",
  "n": 1,
  "reference_images": [
    "https://example.com/reference.jpg"
  ]
}'

Response

Read the completed output

Successful requests return completed image URLs and a request ID. Store the assets you need permanently; routed output URLs may expire.

200 · JSON

{
  "id": "req_01K4…",
  "object": "image.generation",
  "created": 1787424152,
  "data": [
    { "url": "https://static.imgrouter.com/images/req_01K4.webp" }
  ],
  "usage": { "images": 1 }
}

Use GET /v1/requests/{request_id} for reconciliation and GET /v1/balance for the authenticated key's current Credit position.