google-gemini/gemini-cli

Google's official open-source AI agent CLI — brings Gemini into the terminal with tool use, MCP support, and an agentic loop.

What it is

A TypeScript-based command-line agent from Google that wraps the Gemini API (Pro / Flash / Nano models) with a Claude-Code-style harness: tool calls, file edits, terminal access, session memory, MCP client + server support. Distributed at geminicli.com, installable via npm. Apache 2.0 licensed. The Google-first equivalent of Anthropic's Claude Code.

Key features

Gemini-powered agent loop (model-callable tools: file edit, shell, search, etc.).
MCP (Model Context Protocol) client + server.
Apache 2.0 licensed — first-party open-source.
Cross-platform (Linux, macOS, Windows).
Multi-model support across Gemini family (Pro, Flash, Ultra variants).
Tight integration with Google Cloud (Vertex AI) for enterprise auth.

Tech stack

TypeScript primary.
Node.js runtime, npm distribution.

When to reach for it

You're Gemini-aligned and want a first-party CLI agent.
You're comparing first-party offerings: Claude Code (Anthropic), Codex (OpenAI), gemini-cli (Google).
You want an Apache-2.0-licensed reference agent.

When not to reach for it

You're allergic to Google-product lock-in.
You want a multi-provider agent — cline/cline or third-party harnesses fit better.

Maturity signal

105k stars, 14k forks, Apache 2.0, actively maintained. Open-issues count of 1,357 tracks the breadth of Gemini's evolving API + MCP-integration requests.

Alternatives

anthropics/claude-code — Anthropic equivalent.
OpenAI Codex CLI.
cline/cline, obra/superpowers — third-party.

Wiki: google-gemini/gemini-cli