What it is
A hosted demo calculator for anyone curious about Jev. It never evaluates arithmetic: each step Jev picks one of 13 characters, and the page shows the full probability distribution, confidence, and run-to-run jitter.
How it uses Jev
Per answer character, the browser sends the expression and the answer prefix to a Cloudflare Worker, which forwards one System One Choice over 13 options (0–9, ., -, END) to Jev. The returned choice is appended verbatim; the 13 probabilities and confidence are displayed. The loop repeats until END or the cap.
Primitives:choice
Technique worth stealing
Autoregressive character emission with no arithmetic: offer all options every step and use the returned choice, never an argmax.
Try it
npm install, copy .dev.vars.example to .dev.vars, then npm run dev and npx wrangler dev.
Evidence
Each line is one question put to Jev about the README. ≥ 0.60 reads as yes, ≤ 0.40 as no; in between Jev is not making a call.
- Jev-centricyes0.97
- Shows a System One patternyes0.89
- Handles uncertaintyno0.05
- Measuredno0.06
- Runnableyes0.73
- Worth recommendingunclear0.54
- Model replicano0.03
- Problem scopescore on a 0–2 scale0.01
- About Jevyes0.99
Signals by Jev jev-1.13.0, card written by DeepSeek V4.1 Flash from the README on 23 Sept 2026.