API Access and Authentication

You can't build an app in a web browser UI. You need to verify programmatically.

Installation

Google provides the google-generativeai SDK.

• Python: pip install -U google-generativeai
• Node.js: npm install @google/generative-ai

Authentication

The SDK uses your API Key. Security Rule #1: Never hardcode the key.

Good Practice (.env):

1. Create .env file: GEMINI_API_KEY=AIzaSy...
2. Use python-dotenv to load it.

import os
from dotenv import load_dotenv
import google.generativeai as genai

load_dotenv()

genai.configure(api_key=os.environ["GEMINI_API_KEY"])

REST API (cURL)

If you aren't using Python/JS, you can use raw HTTP requests.

curl -H 'Content-Type: application/json' \
     -d '{"contents":[{"parts":[{"text":"Explain metrics"}]}]}' \
     -X POST https://generativelanguage.googleapis.com/v1beta/models/gemini-1.5-flash:generateContent?key=YOUR_API_KEY

Summary

• Install the SDK.
• Use environment variables.
• The API endpoint pattern is https://generativelanguage.googleapis.com/...

In the next lesson, we dive deep into the Python and JavaScript SDKs.