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OpenKey

Nano Banana 2 (Gemini 3.1 Flash Image)

GoogleReleased Jun 18, 2026

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...

Try in playground
Context window
131K tokens
Max output
33K tokens
Input
image, text
Output
image, text
Tokenizer
Gemini
Released
Jun 18, 2026
Reasoning
optional

Pricing

Per 1M tokens. The provider price and our flat 3% fee are separate columns — what you pay is their sum.

Per 1M tokensProvider+ 3% feeYou pay
Input$0.500$0.015$0.515
Output$3.00$0.090$3.09

Supported parameters

  • include_reasoning
  • max_tokens
  • reasoning
  • response_format
  • seed
  • structured_outputs
  • temperature
  • top_p

Call it

OpenAI-compatible: point your SDK at api.openkey.ai/v1 and use model google/gemini-3.1-flash-image.

Code sample language
curl https://api.openkey.ai/v1/chat/completions \
  -H "Authorization: Bearer $OPENKEY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "google/gemini-3.1-flash-image",
    "messages": [{"role": "user", "content": "Hello"}]
  }'
import os
from openai import OpenAI

client = OpenAI(
    base_url="https://api.openkey.ai/v1",
    api_key=os.environ["OPENKEY_API_KEY"],
)

completion = client.chat.completions.create(
    model="google/gemini-3.1-flash-image",
    messages=[{"role": "user", "content": "Hello"}],
)
print(completion.choices[0].message.content)
import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.openkey.ai/v1",
  apiKey: process.env.OPENKEY_API_KEY,
});

const completion = await client.chat.completions.create({
  model: "google/gemini-3.1-flash-image",
  messages: [{ role: "user", content: "Hello" }],
});
console.log(completion.choices[0].message.content);

Questions

How much does Nano Banana 2 (Gemini 3.1 Flash Image) cost via API?
Through OpenKey, Nano Banana 2 (Gemini 3.1 Flash Image) costs $0.515 per 1M input tokens and $3.09 per 1M output tokens. That is the provider price ($0.500 / $3.00) plus a flat 3% fee — nothing else.
What is Nano Banana 2 (Gemini 3.1 Flash Image)'s context window?
Nano Banana 2 (Gemini 3.1 Flash Image) accepts up to 131K tokens of context and returns up to 33K tokens per request.
Is Nano Banana 2 (Gemini 3.1 Flash Image) OpenAI-compatible?
Yes. Send requests to OpenKey's /v1/chat/completions endpoint with model "google/gemini-3.1-flash-image" using any OpenAI SDK — only the base URL and API key change.
What inputs does Nano Banana 2 (Gemini 3.1 Flash Image) support?
Nano Banana 2 (Gemini 3.1 Flash Image) accepts image, text input and produces image, text output.

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