Vercel Labs has open-sourced fx, an experimental coding agent written in Zig. Unlike a full-screen terminal app, it keeps conversation in ordinary terminal scrollback and can return structured output for scripts and CI jobs.
Developers can also connect editors through the Agent Client Protocol or embed fx’s engine using libfx, including a WebAssembly build. Vercel reports a 6.3 MiB binary, single-digit-megabyte baseline memory use and a 10-microsecond cold start; those figures have not been independently verified. The project is pre-1.0 and its releases may require migration steps.
Why it matters
Developers building scripts, CI jobs or editor integrations can use fx without adopting a separate full-screen terminal interface, though its experimental status means embedded users should check migration guidance before upgrading.
