Gemini CLI: Getting Started
Learn the basics of getting started with the Gemini CLI, including installation, authentication, and your first commands.
Why Gemini CLI?
Imagine having an AI assistant that sits in your terminal and can:
- Generate entire applications from a description
- Debug errors by analyzing stack traces
- Write tests, documentation, and commit messages
- Manage your GitHub, databases, and files
- All with your explicit permission at every step
That’s Gemini CLI—an open-source AI agent that transforms how developers work.
Gemini CLI brings the power of Google’s Gemini directly into your terminal. It’s designed for both coding tasks and general productivity, comes integrated with various tools, supports MCP (Model Context Protocol) servers, and offers a generous free tier: 60 requests/min and 1,000 requests/day with a personal Google account.
This is Part 1 of the Gemini CLI tutorial series. In this post, we’ll cover installation, authentication, and your first interactive session with Gemini CLI.
Important Links
Before we dive in, here are the official resources you should bookmark:
- Official Announcement Blog Post
- GitHub Project - The official repository with latest documentation
- Gemini API Key Generator - For API key authentication
Cloud Shell Alternative
If you don’t want to install Gemini CLI locally, you can use it directly in Google Cloud Shell, which comes with Gemini CLI preinstalled. You’ll need a Google Cloud Project with billing enabled. This is a great way to test it without local installation.
Local Installation
The Gemini CLI is a Node.js application, so you’ll need Node.js version 20 or higher installed on your system.
Step 1: Verify Node.js Installation
First, check if you have Node.js 20+ installed:
node --version npm --version If you need to install Node.js, visit nodejs.org.
Step 2: Install Gemini CLI Globally
npm install -g @google/gemini-cli Step 3: Verify Installation
gemini -v This should display the version number (e.g., 0.4.0).
Initial Setup and Authentication
When you run gemini for the first time, the CLI will guide you through setup:
gemini Theme Selection
You’ll first be prompted to select a theme for your terminal interface. Choose one that suits your preferences.
Authentication Method
Next, you’ll choose your authentication method:
Option 1: Google Login (Recommended for Beginners)
- Select “Google login” for easy setup
- This opens your browser for Google authentication
- Provides the free tier: 60 requests/min, 1,000 requests/day
- Ideal for personal projects and learning
Option 2: Gemini API Key
- Use your personal Gemini API key from aistudio.google.com/app/apikey
- Gives you higher quotas
- Good for development and testing
Option 3: Vertex AI
- For enterprise deployments
- Requires a Google Cloud Project with billing enabled
- Better for production use cases
See the Authentication documentation for more details.
Understanding the Gemini CLI Interface
Once authenticated, you’ll see the interactive Gemini CLI interface. Notice the status bar at the bottom showing:
- Current folder (left side) - The project directory you’re working in
- Current model (center) - The model being used (e.g.,
gemini-2.5-pro) - Context remaining (right side) - Available context window
Important: Start from Your Project Directory
Gemini CLI is project-based. Always start it from the directory where you want to work:
# Create a project folder mkdir gemini-cli-projects cd gemini-cli-projects # Then launch Gemini CLI gemini Don’t launch Gemini CLI from your home directory or root folder.
Essential Commands
Type these commands in the Gemini CLI interface:
/help- View all available commands and keyboard shortcuts/docs- Access the Gemini CLI documentation/stats- View session statistics (tokens used, duration, etc.)/tools- List all built-in tools available to the AI/quit- Exit Gemini CLI (or press Ctrl-C twice)
Shell Mode (Passthrough Commands)
You can interact with your system’s shell directly by typing !:
! pwd # Show current working directory ! ls -la # List files in current directory ! cat file.txt # View file contents Press ESC to exit shell mode and return to Gemini mode.
Your First Task: Using the Tools
Let’s explore what tools are available to Gemini CLI. In the CLI, type:
/tools You’ll see a list of built-in tools available, such as:
GoogleSearch- Search the internet- File system operations
- Shell command execution
- And more
These tools help Gemini CLI interact with your environment. Important: You’ll be prompted for permission before any tool is executed—the AI won’t perform actions without your approval.
Your First Prompt
Let’s test Gemini CLI with a simple request. Just type a natural language prompt:
help me understand what I can do with Gemini CLI Or try something more specific:
I need a Python function that validates email addresses The AI will respond and may ask for permission to use tools like file creation or code execution.
Next Steps
You now have Gemini CLI installed, authenticated, and ready to use!
In Part 2, we’ll explore command-line options and parameters for launching Gemini CLI with specific configurations.
In Part 3, we’ll dive into configuration files (settings.json and .env) to customize Gemini CLI’s behavior.
In Part 4, we’ll explore the built-in tools in depth.
In Part 5, we’ll integrate MCP servers to extend Gemini CLI’s capabilities even further.