Open-source Alternative to Claude Code – Google Gemini CLI

Gemini CLI is an open-source, command-line AI tool that brings Google’s Gemini models directly into your terminal. A great alternative to Claude CLI and OpenAI Codex CLI.

It acts as a direct-access AI assistant that helps you work with code, automate jobs, and even interact with your local files without needing to switch contexts.

Features

• Large Codebase Analysis: Query and edit codebases that exceed Gemini’s 1M token context window, handling enterprise-scale projects with ease.
• Multimodal App Generation: Generate new applications from PDFs or sketches using Gemini’s advanced multimodal capabilities.
• Automated Operational Tasks: Handle complex operations like querying pull requests, managing git rebases, and analyzing commit histories.
• MCP Server Integration: Connect with Model Context Protocol servers and extensions, including media generation tools like Imagen, Veo, and Lyria.
• Built-in Google Search: Ground your queries with real-time web search capabilities integrated directly into the AI responses.
• System Tool Integration: Work with local file systems, manipulate images, organize documents, and perform system-level operations through natural language commands.
• Customizable Prompts: Tailor AI instructions and system prompts to match your specific workflow requirements.
• Non-interactive Automation: Invoke Gemini CLI within scripts for automated task execution and workflow integration.

See It In Action

Use Cases

• Explore a New Codebase: When you’re new to a project, you can cd into the repository and ask Gemini CLI questions. For example, you could ask it to “Describe the main pieces of this system’s architecture” or “What security mechanisms are in place?” to get up to speed quickly.
• Work with Existing Code: You can ask it to help with active development. A prompt like, “Implement a first draft for GitHub issue #123” gets it to start writing code based on an issue’s description. It can also help with bigger tasks, like “Help me migrate this codebase to the latest version of Java. Start with a plan.”
• Automate System Tasks: The CLI can interact directly with your machine. I’ve used it for simple things like “Convert all the images in this directory to png, and rename them to use dates from the exif data.” It can also handle more complex file organization, such as organizing PDF invoices by month.
• Create Reports and Apps: You can use it to generate assets for your team. For instance, “Make me a slide deck showing the git history from the last 7 days, grouped by feature and team member” automates a common reporting task.

How to Use It

1. Ensure you have Node.js version 18 or higher installed on your system. You can verify your Node.js version by running node --version in your terminal.

2. Run Gemini CLI directly without installation:

npx https://github.com/google-gemini/gemini-cli

3. Or install the tool globally using npm:

npm install -g @google/gemini-cli
gemini

4. When prompted, sign in with your personal Google account to receive up to 60 model requests per minute and 1,000 model requests per day using Gemini 2.5 Pro. This generous free tier provides substantial usage capacity for individual developers.

5. For higher request limits or specific model requirements, generate an API key from Google AI Studio and set it as an environment variable: export GEMINI_API_KEY="YOUR_API_KEY"

6. Once authenticated, navigate to any project directory and run gemini to start an interactive session. You can then issue natural language commands such as:

• “Write me a Discord bot that answers questions using a FAQ.md file”
• “Give me a summary of all changes that went in yesterday”
• “Refactor this function to improve performance”

Pros

• Exceptional Usage Limits: The free tier offers 60 model requests per minute and 1,000 requests per day, providing the industry’s most generous allowance for individual developers without requiring payment.
• Native Terminal Integration: Works directly within your existing terminal environment without requiring browser interfaces or separate applications, maintaining the efficiency that command-line users prefer.
• Open Source Transparency: The tool is fully open-sourced under Apache 2.0 license, allowing developers to inspect code, verify security implications, and contribute improvements to the project.
• Massive Context Understanding: Handles codebases that exceed Gemini’s 1M token context window, making it suitable for large enterprise projects and complex system analysis.
• Multimodal Capabilities: Can generate applications from PDFs or sketches using Gemini’s multimodal features, bridging the gap between visual concepts and functional code.
• Extensible Architecture: Built-in support for MCP servers and extensions allows users to connect additional tools and capabilities based on their specific needs.

Cons

• Preview Status Limitations: Currently in preview, which means some features may be unstable or subject to change as Google continues development.
• Node.js Dependency: Requires Node.js version 18 or higher, which may necessitate system updates for users running older JavaScript runtime environments.
• Internet Connection Required: Since the tool connects to Google’s Gemini API, it requires a stable internet connection for all AI interactions, limiting offline usage scenarios.
• Google Account Dependency: Authentication requires a personal Google account, which may not align with all organizational security policies or personal privacy preferences.

Related Resources

• Google AI Studio: Access additional API keys and model configurations through Google’s AI development platform for users requiring higher usage limits or specific model variants.
• MCP Server Ecosystem: Explore the Model Context Protocol documentation to understand how to extend Gemini CLI with custom tools and integrations.
• Gemini Code Assist: The tool shares technology with Google’s AI coding assistant, which provides additional AI capabilities within VS Code and other development environments.
• Official Blog Post: Provides context on the tool’s purpose and its integration with Gemini Code Assist.
• Claude Code: The agentic coding tool that lives in your terminal, understands your codebase, and helps you code faster through natural language

FAQs

Q: Do I need a paid API key to use Gemini CLI?
A: No. You can use it for free by signing in with a personal Google account. This gives you a very generous allowance of 60 requests per minute and 1,000 per day using the Gemini 2.5 Pro model. A paid key is only necessary for higher limits or enterprise use.

Q: What is the difference between Gemini CLI and Gemini Code Assist?
A: They are built on the same technology, but for different environments. Gemini CLI is for the terminal, while Gemini Code Assist is an AI assistant integrated into your IDE (like VS Code). They share the same quotas if you use both.

Q: Can Gemini CLI interact with my local files safely?
A: Yes, it can interact with your local files, but it’s designed to ask for your permission before taking actions like writing or modifying a file. You can also run it in “YOLO mode” (--yolo) to automatically accept all actions, though you should use that with caution.

Q: Is Gemini CLI only for coding?
A: While it excels at coding tasks, it’s a general-purpose tool. You can use it for research with its built-in Google Search, content generation, and automating tasks on your local system, like organizing files or converting images.

Q: Can I use Gemini CLI with existing development workflows?
A: Yes, the tool integrates naturally with git repositories, project directories, and standard development tools. You can invoke it within scripts for automation, use it alongside your regular terminal commands, and integrate it with CI/CD pipelines through its non-interactive execution capabilities.