fx is Vercel's compact, open-source coding agent designed to stay out of your way. Built in Zig and delivered as a roughly 6MB native binary, it launches almost instantly and keeps memory and context overhead minimal. You can use it with local or cloud models, extend it with skills, plugins, and MCPs, or embed it into your own agent infrastructure. Its small footprint gives the model more room to work efficiently.
Launch Date:
August 26, 2026