Get a Gemini API Key

Go to aistudio.google.com/apikey and create a free API key. No credit card required for the free tier (which includes generous rate limits).

# Set your API key
export GEMINI_API_KEY="your-api-key-here"

Install the Gemini SDK

Google provides official SDKs for Python and Node.js:

# Python
pip install google-generativeai

# Node.js
npm install @google/generative-ai

Update Your Code

Replace the Anthropic client with the Gemini client. Here's the exact change:

Python (before → after)

# ❌ Before — Claude 4 (returns 410 Gone)
import anthropic
client = anthropic.Anthropic()
response = client.messages.create(
    model="claude-4-opus",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Explain quantum computing"}]
)
print(response.content[0].text)

# ✅ After — Gemini 3.1 Pro (87% cheaper)
import google.generativeai as genai
genai.configure(api_key=os.environ["GEMINI_API_KEY"])
model = genai.GenerativeModel("gemini-3.1-pro")
response = model.generate_content("Explain quantum computing")
print(response.text)

Node.js (before → after)

// ❌ Before — Claude 4 (returns 410 Gone)
import Anthropic from "@anthropic-ai/sdk";
const client = new Anthropic();
const response = await client.messages.create({
    model: "claude-4-sonnet",
    max_tokens: 1024,
    messages: [{ role: "user", content: "Explain quantum computing" }]
});
console.log(response.content[0].text);

// ✅ After — Gemini 3.1 Pro (87% cheaper)
import { GoogleGenerativeAI } from "@google/generative-ai";
const genAI = new GoogleGenerativeAI(process.env.GEMINI_API_KEY);
const model = genAI.getGenerativeModel({ model: "gemini-3.1-pro" });
const result = await model.generateContent("Explain quantum computing");
console.log(result.response.text());

Test and Deploy

Run 5-10 test calls with your existing prompts. Check that responses meet your quality requirements. Then deploy. Your app is back online — and costing 87% less.