Gemini 3.1 Pro API: Guida per Sviluppatori con Esempi di Codice (2026)

# Google AI Studio
model = "gemini-3.1-pro"

# Vertex AI
model = "gemini-3.1-pro@001"

pip install google-genai

from google import genai

client = genai.Client(api_key="YOUR_API_KEY")

response = client.models.generate_content(
    model="gemini-3.1-pro",
    contents="Explain quantum computing in 3 sentences."
)

print(response.text)

npm install @google/genai

import { GoogleGenAI } from "@google/genai";

const ai = new GoogleGenAI({ apiKey: "YOUR_API_KEY" });

const response = await ai.models.generateContent({
  model: "gemini-3.1-pro",
  contents: "Explain quantum computing in 3 sentences.",
});

console.log(response.text);

from google import genai
from google.genai import types

client = genai.Client(api_key="YOUR_API_KEY")

weather_tool = types.Tool(
    function_declarations=[
        types.FunctionDeclaration(
            name="get_weather",
            description="Get the current weather for a city",
            parameters=types.Schema(
                type=types.Type.OBJECT,
                properties={
                    "city": types.Schema(type=types.Type.STRING, description="City name"),
                    "unit": types.Schema(type=types.Type.STRING, enum=["celsius", "fahrenheit"]),
                },
                required=["city"],
            ),
        )
    ]
)

response = client.models.generate_content(
    model="gemini-3.1-pro-preview-customtools",
    contents="What's the weather like in Tokyo?",
    config=types.GenerateContentConfig(tools=[weather_tool]),
)

// In a Y Build project (Cloudflare Worker)
export async function onRequest(context) {
  const response = await fetch(
    "https://generativelanguage.googleapis.com/v1beta/models/gemini-3.1-pro:generateContent",
    {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
        "x-goog-api-key": context.env.GEMINI_API_KEY,
      },
      body: JSON.stringify({
        contents: [{ parts: [{ text: "Your prompt here" }] }],
      }),
    }
  );
  const data = await response.json();
  return new Response(JSON.stringify(data));
}