Gemini CLI — Google AI Coding Agent in Terminal

What it is

Gemini CLI is Google's command-line AI coding agent. It lets you chat with Gemini models directly in the terminal, ask questions about your codebase, edit files, run shell commands, and generate code. It competes with Claude Code and GitHub Copilot CLI.

Gemini CLI targets developers who prefer terminal-based workflows and want AI assistance without leaving the command line. It supports multiple Gemini model variants.

How it saves time or tokens

Instead of switching between a web browser (for AI chat) and terminal (for coding), Gemini CLI keeps everything in one place. Ask the AI to explain code, generate tests, refactor functions, or debug errors -- all from the same terminal session where you write code.

The CLI has direct access to your filesystem, so it can read project files and provide context-aware suggestions without manual copy-pasting.

How to use

1. Install Gemini CLI:

npm install -g @google/gemini-cli

1. Authenticate with your Google account:

gemini auth login

1. Start chatting in your project directory:

gemini
# Opens an interactive session with access to your project files

Example

# Ask about your codebase
$ gemini 'Explain the authentication flow in this project'

# Generate a test file
$ gemini 'Write unit tests for src/utils/validators.ts'

# Fix a bug
$ gemini 'The login endpoint returns 500 when email is missing. Fix it.'

# Run commands through the AI
$ gemini 'Find all TODO comments in the project and list them'

Interactive mode example:

> What does the handlePayment function do?

Gemini: The handlePayment function in src/api/payments.ts:
1. Validates the payment amount and currency
2. Creates a Stripe PaymentIntent
3. Returns the client secret for frontend confirmation
...

Related on TokRepo

• AI Tools for Coding -- Compare AI coding assistants and terminal agents
• AI Tools for Automation -- CLI automation tools for developers

Common pitfalls

• Gemini CLI requires a Google account and may have usage limits on the free tier. Check Google's pricing for current quotas.
• File editing operations modify your code directly. Always use version control (git) so you can revert AI-generated changes.
• Context window limits apply. For very large projects, the CLI may not be able to read all files simultaneously. Point it to specific directories or files.