Google: Nano Banana 2 (Gemini 3.1 Flash Image)

google/gemini-3.1-flash-image

Gemini 3.1 Flash Image, a.k.a. "Nano Banana 2," is Google’s latest state of the art image generation and editing model, delivering Pro-level visual quality at Flash speed. It combines advanced context...

vision

MODALITIES

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INPUT PRICE

$0.50per 1M

OUTPUT PRICE

$3per 1M

CONTEXT

131.1K

RELEASED

Jun 18, 2026

Provider				Cache	Uptime	Chat
FastAPI	—	$0.5	$3	Cache read$0.05

Capabilities

Input modalities

imagetext

Output modalities

imagetext

Features

include_reasoningmax_tokensreasoningreasoning_effortresponse_formatseedstructured_outputstemperaturetop_p

Get your API key

Create an API key from the Keys page, then set it as an environment variable:

export ONLIST_API_KEY=sk-...

Make your first request

Endpoints

POSThttps://onlist.io/v1/images/generations

Request Headers

Authorization:Bearer $ONLIST_API_KEY

Content-Type:application/json

Model:google/gemini-3.1-flash-image

Code samples

curl https://onlist.io/v1/images/generations \
  -H "Authorization: Bearer $ONLIST_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
       "model": "google/gemini-3.1-flash-image",
       "prompt": "A white siamese cat",
       "n": 1,
       "size": "1024x1024"
     }'

Replace $ONLIST_API_KEY with the API key from your Keys page.

Authentication

All requests must include an Authorization: Bearer <TOKEN> header. Generate keys from the Keys page; keys can be scoped to specific models, groups, IP ranges, and rate limits.

Supported parameters

Name	Type	Description
`include_reasoning`
`max_tokens`	integer	Maximum number of tokens to generate in the completion.
`reasoning`
`reasoning_effort`	string	Constrains effort on reasoning. Supported values: "low", "medium", "high".
`response_format`	object	Specifies the output format. Use {"type": "json_object"} for JSON mode.
`seed`	integer	If specified, the system will attempt deterministic sampling for reproducible results.
`structured_outputs`
`temperature`	number	Sampling temperature between 0 and 2. Higher values make output more random.
`top_p`	number	Nucleus sampling. The model considers tokens with top_p probability mass.

These are the request parameters this model accepts. Parameter semantics follow the OpenAI Chat Completions specification.