fx

Meet fx

fx is an experimental coding agent and command-line tool written in Zig. Its small native binary can run interactive sessions or individual requests in a terminal, continuous integration environment, or agent sandbox. The interface keeps tool activity alongside the conversation and preserves scroll history, with a full transcript available when more detail is needed.

Developers can embed the core through libfx, supply their own tools, and connect skills or MCP servers. WebAssembly support allows applications to provide a browser workspace while controlling storage, networking, and tool access. The project is open source under Apache 2.0 and supports different model providers, including local inference. Its experimental status means interfaces and behavior can change frequently.