Constellation · The Cartographer

Gemini CLI: Google's agent in your terminal

Twelve guides to Google's open-source terminal agent: what Gemini CLI is and how to install and authenticate it, GEMINI.md context, prompting the 1M-token window, tools and slash commands, MCP, extensions, settings, models, sandboxing and approvals, headless automation and CI, and an honest comparison with Claude Code and Codex.

12 of 12 guides live · fact-checked against official docs

Chapter 0

☆

What Is Gemini CLI

Understand what Gemini CLI actually is, how its agentic loop works, and the three doors to Google's Gemini models.

11 mingemini-cli / agentic-coding / google / fundamentals / gemini-3

Chapter 1

☆

Install & First Session

Install Gemini CLI, pick the right auth before the June 18 cutoff, and run your first session.

11 mingemini-cli / installation / authentication / quotas / getting-started

Chapter 2

☆

GEMINI.md context files

Master the GEMINI.md hierarchy, @-imports, and the /memory command — then compare it honestly to CLAUDE.md and AGENTS.md.

12 mingemini-cli / GEMINI.md / memory / context / CLAUDE.md / AGENTS.md

Chapter 3

☆

Prompting Gemini

Fill the 1M-token window, place your ask last, and turn a good prompt into a script.

11 mingemini-cli / prompting / context-window / multimodal / headless

Chapter 4

☆

Tools & Commands

Master the built-in tools, slash commands, @ file refs, and ! shell — and who calls what.

10 mingemini-cli / tools / slash-commands / shell / cli

Chapter 5

☆

MCP servers

Wire up local and remote MCP servers in Gemini CLI without the trust, secret, and transport traps.

11 mingemini-cli / mcp / configuration / tools / oauth

Chapter 6

☆

Extensions & Commands

Turn repeated workflows into TOML slash commands, then bundle and share them as installable Gemini CLI extensions.

11 mingemini-cli / extensions / slash-commands / toml / mcp

Chapter 7

☆

Settings & Config

Master the seven-layer settings.json precedence model and never wonder which config is winning again.

11 mingemini-cli / configuration / settings.json / precedence / telemetry / themes / env

Chapter 8

☆

Models & Context

Master the Gemini model lineup, auto-routing, the 1M-token window, and which auth path unlocks which models and quotas.

11 mingemini-cli / models / context-window / quotas / model-routing / authentication

Chapter 9

☆

Sandbox & Approvals

Master the two-layer safety model that keeps an agent that edits files and runs shell commands from wrecking your machine.

11 mingemini-cli / sandboxing / approvals / security / checkpointing

Chapter 10

☆

Automation & CI

Script Gemini CLI headless and wire it into CI with the official GitHub Action.

11 mingemini-cli / automation / ci-cd / github-actions / headless / scripting

Chapter 11

☆

Gemini vs Claude vs Codex

Pick the right terminal coding agent — an honest, current three-way comparison.

11 mingemini-cli / claude-code / codex-cli / comparison / sandboxing / pricing / mcp