Google Gemini CLI

Gemini CLI is Google's open-source agentic terminal tool, known for very large context windows and generous free tiers.

Install

npm install -g @google/gemini-cli
gemini

Authenticate with OAuth or a GEMINI_API_KEY from aistudio.google.com.

Daily use

gemini "summarize this repo"
gemini "add a rate limiter to the API"
gemini --yolo   # auto-approve everything (be careful!)

Gemini CLI can also launch an interactive chat with an attached web preview, and it supports MCP servers via .gemini/settings.json.

MCP config example

{
  "mcpServers": {
    "github": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-github"],
      "env": { "GITHUB_PERSONAL_ACCESS_TOKEN": "..." }
    }
  }
}

Strengths

• 1M-token context — it can read enormous codebases in one pass.
• Open source — you can inspect and extend it.
• Free/cheap — the API is often the most budget-friendly of the big three.

Tip: the gemini interactive UI shows a browser preview for web work — handy for iterating on HTML/CSS tasks.