Introduction to Gemini's Image Generation and Symfony

Welcome to the first lesson of our course, "Creating Images with Gemini's Image Generation and Symfony." In this course, you will explore AI-driven image generation using Google's Gemini API and its native image generation model (Nano Banana, gemini-3.1-flash-image). Our journey begins with understanding how to set up the environment and generate a simple image using PHP with Symfony. This foundational lesson will set the stage for more advanced topics in subsequent units.

Before we dive into generating images, it's crucial to set up our environment correctly. First, ensure you have access to the Gemini API by retrieving your API key. This key is essential for authenticating your requests to the API.

For this lesson, you'll need to use Composer, PHP's package manager, to install the necessary libraries. We'll be using Symfony components, particularly the Symfony HTTP Client for making API requests.

Here's how to set up a basic Symfony project with the required components:

# Create a new Symfony project (or use an existing one)
composer create-project symfony/skeleton gemini-image-app

# Navigate to the project directory
cd gemini-image-app

# Install the HTTP Client component
composer require symfony/http-client

Note that the environment will be fully set up for the practices section, so you can focus on the exercises without worrying about the setup.

You can get more details about how to use the Gemini Image Generation API from Google's documents. There, you can get the important details about connecting to the API, namely the GEMINI_BASE_DIR and the GEMINI_API_KEY.

For example, when connecting directly to Gemini, the GEMINI_BASE_URL will be https://generativelanguage.googleapis.com/ and the GEMINI_API_KEY is your own secret. In all of our examples and practices, we will provide these variables to you so you don't need to be concerned with them for now.

For interacting with the Gemini API in PHP, we'll use Symfony's HTTP Client component. This provides a powerful and flexible way to make HTTP requests to external APIs.

Since the Gemini API for image generation requires direct REST API calls, we'll use the Symfony HTTP Client to construct and send our requests. Later in the course, we'll encapsulate this functionality into reusable services.