Introducing CHOMATO: A lightweight harness for LFM 2.5 with superpowers.

Karol Rybak — Sat, 08 Aug 2026 05:35:46 +0000

Have you ever wondered how cool it would be if your harness could:

Branch the KV-cache without huge buffers.
Attach precalculated context blocks however you please.
Give perfect structured responses in any shape you'd like.
Run on the backend, frontend, or anywhere WebGPU works.
Do all of that in less than 1 GB of RAM.

I definitely wanted one, and since there wasn't any — I built my own.

The GUI is mostly for diagnostics (styled after Classic Mac OS), but you can check out the live online demo here: https://3ksoft.github.io/chomato/

Code: https://github.com/3ksoft/chomato (AGPL-3.0). It also uses two libraries I've authored — they aren't on npm yet, but current versions are available on my GitHub under the MIT license.

The API is a bit unusual if you're used to traditional ones:

const result = await engine.generate(
  type({ id: "number", name: "string < 64" }),
  { checkpoint, blocks },
);

Basically, sparse (structured) mode is the engine default. If you just want plain text, you use type("string < max_length").

Hope you'll have as much fun using it as I had while building it!

DEV Community: Karol Rybak

Introducing CHOMATO: A lightweight harness for LFM 2.5 with superpowers.