What it is
A chess match between Jev, which selects from legal moves, and a text-writing opponent (Qwen, GPT or Claude). Every game, move and rejected attempt is recorded to SQLite, with 15-second video export.
How it uses Jev
Jev receives the board state and a Choice question containing every legal move from python-chess. It returns the preferred move, a probability for every alternative, and a confidence score. The move is used directly; illegal moves are unrepresentable.
Primitives:choice
Technique worth stealing
Constrain a System One model to selection over a supplied option list, making illegal outputs unrepresentable.
Try it
uv sync; uv run jev-chess serve
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-centricyes0.88
- Shows a System One patternunclear0.58
- Handles uncertaintyno0.08
- Measuredno0.12
- Runnableunclear0.50
- Worth recommendingunclear0.53
- Model replicano0.06
- Problem scopescore on a 0–2 scale0.02
- About Jevyes0.98
Signals by Jev jev-1.13.0, card written by DeepSeek V4.1 Flash from the README on 20 Sept 2026.