Nano Banana 2
Google · Gemini 3.1 Flash Image
nano-banana-2-ext Google’s fast image model for everyday generation and edits. Resolutions from 0.5K to 4K, including very wide poster ratios. Use Pro when the final layout needs more care.
Completed images appear here after a successful Credit debit.
Call Nano Banana 2
ImgRouter uses one request contract. Send this model ID to POST /v1/images/generations. Examples below match the recommended defaults on this page.
/v1/images/generationscurl https://api.imgrouter.com/v1/images/generations \
-H "Authorization: Bearer $IMGROUTER_API_KEY" \
-H "Content-Type: application/json" \
-H "Idempotency-Key: nano-banana-2-ext-generate-001" \
-d '{
"model": "nano-banana-2-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
}'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-2-ext. Official aliases: nano-banana-2-ext, gemini-3.1-flash-image-preview, nano-banana-2.promptstring · requiredText instruction, 1–5,000 characters. Describe the image or the edit you want.sizestring · default 16:9Aspect ratio. Supported: auto, 1:1, 3:2, 2:3, 4:3, 3:4, 16:9, 9:16, 5:4, 4:5, 21:9, 1:4, 4:1, 1:8, 8:1. Prefer an explicit ratio instead of auto when you need predictable framing.resolutionstring · default 2KOutput tier. Supported: 0.5K, 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.Model aliases
nano-banana-2-ext — ImgRouter route. Compatible with gemini-3.1-flash-image-preview.
gemini-3.1-flash-image-preview — Official standard name on the upstream docs.
nano-banana-2 — Official-channel alias. Not this ImgRouter route.
Official-only fields
These appear on the official docs page. ImgRouter does not accept them on the unified body.
nsfw_checkboolean · default falseUpstream-only. ImgRouter does not accept this field; keep moderation on your side if needed.official_fallbackboolean · default falseUpstream-only official-channel fallback. Not accepted on ImgRouter requests.google_searchboolean · default falseUpstream-only text search enhancement. Not accepted on ImgRouter requests.google_image_searchboolean · default falseUpstream-only image search. Requires google_search on the official API; not accepted here.image_urlsstring[]Official docs name for reference images. Use reference_images on ImgRouter instead.Size, resolution, and output
Route notes
Supports generation and editing up to 4K with fourteen reference images.
Extreme banner and poster ratios are supported, including 1:8 and 8:1.
Use auto only when automatic framing is acceptable.
Edit with reference images
Send public HTTPS source images with the same core controls. This route accepts up to 14 reference images.
/v1/images/editscurl https://api.imgrouter.com/v1/images/edits \
-H "Authorization: Bearer $IMGROUTER_API_KEY" \
-H "Content-Type: application/json" \
-H "Idempotency-Key: nano-banana-2-ext-edit-001" \
-d '{
"model": "nano-banana-2-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"
]
}'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.
{
"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.