How to install and use Google Gemini CLI: npm, brew, sign-in, and @ files

Install Gemini CLI, sign in with Google, and use @ file references for your first terminal agent prompt.

The first hour with Google Gemini CLI usually breaks on Node.js, a missing gemini on PATH, or an unfinished Google sign-in. Install per the official README and geminicli.com/docs, log in from your project folder, then use @ to inject file context into your first prompt.

The query is how to install Google Gemini CLI and use @ files. This page follows google-gemini/gemini-cli install and auth notes plus the file-management tutorial for @ references. It is Google’s terminal agent, not this site’s meeting product. For a short huddle to review a diff, open a room on wbmeet; see how to create and join a room.

Who Gemini CLI is for

Gemini CLI is an open-source (Apache 2.0) terminal-first agent: read repos, edit files, run shell, optional Google Search grounding. Many developers use Sign in with Google (OAuth); the README documents free-tier limits for personal accounts (see cloud.google.com/gemini/docs/quotas). Alternatives: GEMINI_API_KEY from AI Studio or Vertex AI for enterprise.

Install with npm or Homebrew

1. 1

   Prepare Node.js

   npm install needs a supported Node.js (see the official installation page). Confirm node -v and npm -v. Restricted environments can use the README conda + nodejs recipe.

2. 2

   Global install or npx

   npm install -g @google/gemini-cli. macOS/Linux: brew install gemini-cli. No global install: npx @google/gemini-cli. Channels: @latest, @preview, @nightly per Release Channels in the README.

3. 3

   Verify the command

   New terminal: gemini --version. If command not found, add npm’s global bin directory to PATH.

Sign in with Google (or API key)

1. 1

   Start from the project directory

   cd into your repo and run gemini. Choose Sign in with Google and finish OAuth in the browser.

2. 2

   Code Assist license (optional)

   For org Gemini Code Assist, README suggests export GOOGLE_CLOUD_PROJECT="YOUR_PROJECT_ID" before gemini.

3. 3

   API key path (optional)

   Create a key at aistudio.google.com/apikey, then export GEMINI_API_KEY="YOUR_API_KEY". Never commit keys to Git.

First prompt and @ file context

1. 1

   Force-read with @

   Official file-management tutorial: @src/foo.ts reads the file immediately and injects it. Example: @src/utils/helpers.ts Explain what each export does.

2. 2

   Multiple files and folders

   Chain references: @src/A.tsx @src/types/User.ts. Whole folder: @src/utils/ (large folders use more tokens—prefer named files first).

3. 3

   One reviewable task

   Follow with a diff-friendly ask: fix one typo in @README.md and show the unified diff before writing. Approve small edits only in hour one.

# First hour · Gemini CLI · 2026-09
npm install -g @google/gemini-cli
# or: brew install gemini-cli
gemini --version
cd /path/to/your/repo
gemini
# Sign in with Google
@src/main.ts Summarize the entry point and list public exports.
@src/main.ts Add one-line JSDoc to the main export; show diff before writing.

Install vs auth

Official path: install Gemini CLI → Google sign-in or API key → use @file for context → small change with reviewed diff. Trust geminicli.com/docs and your installed version.

Vs other terminal agents

Commands and auth differ per vendor; you can keep several CLIs. See our Claude Code install note for comparison.

What is GEMINI.md?

Project-level context file supported by the CLI—configure after you are comfortable with @ references.

Not a meeting-product guide

Only Gemini CLI’s first hour. Short whiteboard call: wbmeet.

Questions worth checking