altrouter.ai
Models/Google/Nano Banana Fast
NB

Google: Nano Banana Fast

Imagenano-banana-fast

Google's ultra-fast, cheap image generation.

API docs
Playgroundnano-banana-fast
Reference image
Aspect ratio
Seed
Latency4.9 s
24hnow
Specifications
Authorgoogle
ModalityImage
Price$0.035 / image$0.039 / image
Savings10%
Quick start
from openai import OpenAI

client = OpenAI(
    base_url="https://api.altrouter.ai/v1",
    api_key="ar-...",
)

img = client.images.generate(
    model="nano-banana-fast",
    prompt="a red fox in the snow",
)
print(img.data[0].url)

Same OpenAI-compatible endpoint — just swap base_url and key.

API

OpenAI-compatible image generation endpoint. The result is re-hosted on our CDN and returned as a URL.

POST/v1/images/generations
Body parameters
modelstringrequired"nano-banana-fast"
The model id.
promptstringrequired
The text description of the image.
imagestringURL or base64
Reference images for editing.
aspect_ratioenum1:1 · 16:9 · 9:16 · 4:3 · 3:4 · 3:2 · 2:3 · 5:4 · 4:5 · 21:9 · autodefault 1:1
Output aspect ratio.
seednumber0–2147483647
Seed for reproducibility.
Response
createdinteger
Unix creation time (seconds).
dataarray
Images. Each: url (our CDN), b64_json, revised_prompt.
Example
cURLPythonJSON
curl https://api.altrouter.ai/v1/images/generations \
  -H "Authorization: Bearer ar-..." \
  -H "Content-Type: application/json" \
  -d '{
  "model": "nano-banana-fast",
  "prompt": "a red fox in the snow",
  "aspect_ratio": "1:1"
}'
Errors
400Invalid request.
401Missing or invalid API key.
402Insufficient credits, or the key’s spending cap is exhausted.
404Model not found.
429Rate limit exceeded.
More from Google
Gemini 3.1 Flash Lite
gemini-3.1-flash-lite
Gemini 2.5 Flash
gemini-2.5-flash
Gemini 3 Flash
gemini-3-flash
Gemini 3.5 Flash
gemini-3.5-flash
Gemini 2.5 Pro
gemini-2.5-pro
Gemini 3.1 Pro
gemini-3.1-pro
Gemini 3 Pro
gemini-3-pro
Nano Banana
nano-banana
Nano Banana 2
nano-banana-2
Nano Banana Pro
nano-banana-pro
Veo 3.1
veo-3.1
Veo 3.1 Fast
veo-3.1-fast