fx

fx is a lightweight, open-source AI coding agent designed to operate directly within Unix-style terminals. It helps developers inspect repositories, edit source files, execute shell commands, and automate software development tasks through natural language. The agent supports web searching, URL reading, background processes, and delegation to specialized subagents. Users can connect through Vercel AI Gateway, supported AI subscriptions, or OpenAI-compatible model endpoints. Its interface preserves familiar terminal scrolling, searching, and text selection. Configurable permission modes control whether actions require approval or undergo automated security checks. Sessions are saved locally and can be resumed or compacted when necessary. fx also supports scripting, MCP servers, reusable skills, and integration with external development tools.