Building Smart: How to Integrate Gemini AI

The Shift from Static to Generative

For years, "Full Stack" meant a database, a backend API, and a frontend. Today, that definition is expanding. With tools like Gemini and Firebase, the "backend" can now think, summarize, and generate.

In this post, I’ll walk through how to integrate Google's Gemini model directly into a Next.js application hosted on Firebase. We will move beyond simple API calls and look at how to structure this in a modern "Front to Back" architecture.

The Stack

• Framework: Next.js 15 (App Router)
• Backend: Firebase (Firestore & Functions)
• AI Model: Gemini 1.5 Flash (via Vertex AI for Firebase)

Why Vertex AI for Firebase?

You could call the Gemini API directly, but using the Firebase SDK offers distinct advantages for full-stack developers:

1. Security: You can use Firebase App Check to ensure only your apps can access the AI model.
2. Integration: It plays nicely with Firestore if you want to save the generation results immediately.

Step 1: Initialize the SDK

First, ensure you have the necessary packages installed in your Next.js project:

npm install firebase @firebase/vertexai-preview