Gemini CLI
Google's open-source terminal coding agent powered by Gemini 2.5 Pro. Features a 1M token context window, native MCP server support, and is free to use within Gemini API limits. A direct Claude Code and Aider competitor from Google.
Claude Code
Terminal-first agentic coding assistant from Anthropic. Full MCP client support, codebase-aware, runs multi-step tasks autonomously.