Gemini CLI, an open-source AI agent developed by Google that integrates the Gemini 2.5 Pro model directly into the terminal for coding and automation tasks. Multiple sources highlight its generous free tier, offering high usage limits without charge, which is seen as a competitive move against similar paid tools like Claude Code. While the free tier might involve data collection for model improvement, users can opt for a paid API key to prevent this and potentially gain higher capacities. The articles detail how to set up Gemini CLI, either directly through Google Cloud/AI Studio API keys or via OpenRouter integrations, and mention its utility in various development environments like VS Code, as well as its capabilities for tasks such as debugging, generating code, and automating workflows.