====== Gemini CLI ======

**Gemini CLI** is Google's open-source AI agent that brings the power of Gemini directly into the terminal. Built in TypeScript under the Apache 2.0 license, it leverages Google's Gemini models with a massive 1M-token context window to help developers write, debug, and understand code from the command line. With over **98,000 GitHub stars**, it is one of the most popular CLI coding agents in the ecosystem.(([[https://github.com/google-gemini/gemini-cli|GitHub Repository]]))(([[https://blog.google/technology/developers/gemini-cli/|Google Blog Announcement]]))(([[https://arxiv.org/|Google DeepMind Research]]))

GitHub: [[https://github.com/google-gemini/gemini-cli|google-gemini/gemini-cli]] | Website: [[https://geminicli.com]](([[https://geminicli.com|Official Website]]))

===== Key Features =====

  * **1M-Token Context Window** — Processes entire codebases in a single session, enabling deep understanding of large projects
  * **Plan Mode** — Analyzes codebases and creates action plans before making changes, separating analysis from execution
  * **MCP Integration** — Supports Model Context Protocol for both client and server roles, extending capabilities through external tools
  * **Multi-Tool Support** — File editing, shell command execution, web search, and code analysis built in
  * **GitHub Actions Integration** — Automates issue triage, PR reviews, test generation, and commit workflows
  * **Free Tier Access** — Generous free usage through Google AI Studio authentication
  * **Sandbox Execution** — Runs commands in isolated environments for safety

===== Architecture =====

Gemini CLI is structured as a monorepo with multiple packages:

  * **Core Engine** — TypeScript-based agent loop handling conversation, tool dispatch, and streaming
  * **Tool System** — Modular tool architecture with file operations, shell execution, search, and MCP bridges
  * **Configuration** — Supports ''GEMINI.md'' instruction files (similar to Claude's ''CLAUDE.md'') for project-level customization
  * **Authentication** — Google AI Studio OAuth, Vertex AI, and API key support

===== Usage Example =====

<code bash>
# Install globally via npm
npm install -g @anthropic-ai/gemini-cli

# Start interactive session in a project
cd my-project
gemini

# Use with a direct prompt
gemini "explain the authentication flow in this codebase"

# Use Plan Mode for complex changes
gemini "refactor the database layer to use connection pooling" --plan
</code>

===== How It Works =====

<mermaid>
graph TD
    A[User Prompt] --> B[Gemini CLI Agent Loop]
    B --> C{Plan Mode?}
    C -->|Yes| D[Analysis Phase - Read Only]
    D --> E[Generate Action Plan]
    E --> F[User Approval]
    F --> G[Execution Phase]
    C -->|No| G
    G --> H[Tool Selection]
    H --> I[File Edit Tool]
    H --> J[Shell Execution Tool]
    H --> K[Search Tool]
    H --> L[MCP Tool Bridge]
    I --> M[Apply Changes]
    J --> M
    K --> M
    L --> M
    M --> N[Stream Response to Terminal]
    N --> B
</mermaid>

===== Comparison =====

^ Feature ^ Gemini CLI ^ Claude Code ^
| Context Window | 1M tokens | 200K tokens |
| Language | TypeScript | TypeScript |
| License | Apache 2.0 | Proprietary |
| Model Lock-in | Gemini only | Claude only |
| MCP Support | Yes | Yes |
| Plan Mode | Yes | Yes |
| GitHub Stars | ~99K | N/A |

===== See Also =====

  * [[cline|Cline]] — Model-agnostic autonomous coding agent
  * [[roo_code|Roo Code]] — Multi-mode CLI agent forked from Cline
  * [[amazon_q_cli|Amazon Q CLI]] — AWS's agentic terminal
  * [[trae_agent|Trae Agent]] — ByteDance's research-friendly CLI agent
  * [[droid_factory|Droid (Factory)]] — Factory's multi-model CLI coding agent

===== References =====