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jev-system-one-rlcd

Local reproduction of Jev-style inference that reads option-token logits from a small LLM in one pass, with an honest failure log.

Projectresearch

Overview

This repository reproduces the inference mechanism behind Jev-style decision models on a laptop, while being explicit that it does not reproduce Jev's weights or its full RLCD (Reinforcement Learning for Calibrated Decisions) stack. A bounded decision is phrased as a multiple-choice prompt with single-token letter labels; one prefill pass yields the last-position logits, and a softmax restricted to the option-letter tokens gives a real distribution over allowed answers. The model never generates text, mirroring SGLang's /v1/score approach.

The author also documents a first attempt that deleted the pretrained lm_head and attached untrained linear heads, which produced noise, and keeps it for comparison. On an M1 laptop, scoring with SmolLM-135M took about 60 ms versus about 1.6 s to generate JSON, roughly 26 times faster, but both 135M models mis-routed a test ticket at near-chance confidence. The README is clear that the mechanism is fast and structurally safe while accuracy needs a larger model and calibration. An RLCD training loop with proper scoring rules is included.

What the decision model decides

TypeQuestionAnswers
ChoiceWhich of four teams should handle this support ticket? (letter-labelled options)—

How it works

  1. Format options with single-token letter labels
  2. Run one forward pass and take last-position logits
  3. Softmax over the option-letter tokens only
  4. Optionally train calibration with the RLCD loop

Strengths

  • Invalid outputs are impossible by construction
  • README reports ~19-26x speedup over generation on small models
  • Candid account of what failed and why

Caveats

  • 135M models route at near-chance accuracy
  • Does not reproduce Jev weights or full calibration
  • Research and teaching code

Getting started

pip install -r requirements.txt && python3 jev_scoring.py

At a glance

Type
Project
Status
research
Language
Python
Runtime
PyTorch / transformers
Has code
yes

Use cases and integrations

How curated lists describe it

Frequently asked questions

Does this reproduce Jev?

Only the inference mechanism of reading option probabilities; not Jev's weights or its full calibration training.

How fast is it?

About 60 ms per decision on an M1 laptop with a 135M model, versus over a second for JSON generation.

Is it accurate?

Not at 135M parameters; the README notes accuracy needs a larger model and calibration.

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