Laya: The Open-Source Alternative to Jev

Laya is an open decision model that answers the same three question types as Jev — choice, score and noul — without sending anything to an API. It is a non-autoregressive model of roughly 421 million parameters, which is why it fits in 1–2 GB of RAM, runs on a laptop CPU, and has been ported to Apple's MLX and Core ML stacks.

It became the centre of the launch-week argument: the maintainers say the architecture was built and open-sourced about a year before Jev shipped, and the r/LocalLLaMA thread asking who was first is the single most-upvoted discussion of the whole release. For builders the argument matters less than the practical consequences: no API key, no per-call bill, no data leaving the machine, and no terms that restrict benchmarking.

What it does

Numbers worth knowing

MetricLayaReference
Parameters~421MEnglish checkpoint; multilingual variant is smaller
Memory~1–2 GB RAMComfortable on CPU-only boxes
Latency, short decisions~35 ms on GPUReported on the model card
Latency, MLX on M3 Max7–14 msValidator port with published benchmarks
Latency, Core ML + Neural Engine~5 msValidated port, reproducible speed and energy runs
Routing accuracy0.766vs 0.727 for the hosted model, on the public decision benchmark

Treat the accuracy row as a starting point, not a verdict: both sides were moving weekly during launch, and the eval set is shared and public. The honest summary is that a 400M-parameter model running locally lands in the same range as the hosted frontier model on this task family.

How to get it

When to use Laya instead of Jev

And when to stay hosted: you want the strongest calibration on hard, messy input, you do not want to operate inference, or you need the vendor's own support and terms behind a production decision.

Last updated: 2026-09-21 · sources & corrections