fx is Vercel's tiny, open-source coding agent built to get out of your way. Written in Zig and shipped as a ~6MB native binary, it starts almost instantly while keeping memory and context overhead low. Use it with local or cloud models, extend it with skills, plugins and MCPs, or embed it into your own agent infrastructure. Small by design, so the model gets more room to work.

Vercel just released a coding agent, and it's tiny.

fx is an open-source coding agent written in Zig and packed into a ~6MB binary. It starts almost instantly, uses very little memory, and feels more like a Unix tool than another full IDE inside your terminal.

What caught my attention is that the minimalism isn't just about binary size. fx also keeps the system prompt and tool surface small, so less of your context window is spent on the harness itself.

It's model agnostic, works with local or cloud models, supports Wasm, and can be extended with skills, plugins and MCPs. Vercel also designed it to be embeddable, which makes the idea of running many lightweight coding agents particularly interesting.

It's still very early and experimental, but I like the direction: instead of making the coding agent more complicated, make the harness disappear.

The idea of giving the model more room by reducing tool overhead is interesting. Curious to see what developers build with this.

Vercel just released a coding agent, and it's tiny.

What caught my attention is that the minimalism isn't just about binary size. fx also keeps the system prompt and tool surface small, so less of your context window is spent on the harness itself.

It's still very early and experimental, but I like the direction: instead of making the coding agent more complicated, make the harness disappear.

The idea of giving the model more room by reducing tool overhead is interesting. Curious to see what developers build with this.

fx (by Vercel)

Vercel's tiny, open-source coding agent

Vercel's tiny, open-source coding agent