handwired

Handwired turns program logic (if-else, comparisons, loops, state) into the math a neural net runs: weighted sums and ReLU. The weights are written by hand, not learned, so results are exact with no training, and because everything stays differentiable you can later unfreeze those weights and train them. It's a free, MIT-licensed research project from Cheng Lou, who also wrote the Pretext text-layout library.

The tagline says it turns your regular JavaScript into a neural net. Its own docs say otherwise: "No tool converts existing JavaScript source into a program." You rewrite the logic by hand in builder code, calling functions like emitCompare that append operations. Loops can't exit early, so they become counts, trees or tables. Setup is a clone, bun install, bun start. It isn't on npm. Programs run in JavaScript on the CPU; only the demo that searches 100,000 JSON documents per keystroke uses WebGPU.

Solo: worth an afternoon with the demos. Small and larger teams: nothing to ship yet. Free, no paid tier.

The catch: it's a days-old lab, not a library. No package, no stable API, and an evaluation throws when a value leaves its declared range.