Gemini CLI Full Tutorial: Install to AI Agent (Beginner Guide)

Gemini CLI Tutorial: Google's free AI agent that writes code, runs tests and fixes bugs directly from your terminal. In this video we install Gemini CLI, use Plan Mode, and build a complete Task Manager app from a single prompt (11/11 tests passing ✅). What you'll learn: ✔ What Gemini CLI is and how an AI agent differs from a chatbot ✔ Installation with Node.js + npm (Windows/Mac) ✔ Free Gemini API key setup (Google AI Studio) ✔ Fixing slow responses: /model → Flash Lite ✔ Planning a project with Plan Mode (/plan) ✔ Understanding an existing codebase ✔ Debugging with AI ✔ GEMINI.md: save project context and cut token usage ✔ /quit session stats: track your token usage ⏱ Chapters 0:00 What is Gemini CLI? 0:35 What is a CLI (Command Line Interface)? 1:13 Chatbot vs AI Agent 1:30 Installation (Node.js + npm) 2:33 Authentication & free API key 3:40 First prompt 4:14 Fixing slow responses: switch to Flash Lite 5:36 Project: Task Manager app requirements 9:08 Plan Mode (/plan) 12:25 Phase-wise implementation & permissions 14:44 Automated testing (npm test) 15:50 Live demo: app built in 1 minute 17:25 Benefits of AI-assisted development 17:44 Understanding an existing codebase 19:36 Debugging with Gemini CLI 21:11 GEMINI.md: persistent project context 23:55 Session stats & token usage 24:40 Wrap-up 💻 Commands used npm install -g @google/gemini-cli gemini /auth /model /plan /quit 🔗 Google AI Studio (API key): https://aistudio.google.com 📺 More from Square Brackets Tech: https://youtube.com/@SquareBracketsTech #geminicli #aiagents #aicoding #gemini #claudecode