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Jev + Gymnasium

A harness for evaluating TypeSafe Jev as a policy in Gymnasium and Atari environments: adapters turn observations into structured JSON and Jev picks a legal action through a single Choice question, with no training.
Stars
8
Language
Python
Reading time
2 min
Published by
Community
Author
taodav
Last verified
Oct 2026

Highlights

  • Supported environments: CartPole, Pong, Breakout and Ms. Pac-Man; Montezuma's Revenge is experimental with development paused.
  • Defaults: model jev-1.13.0, two emulator frames per Atari decision, sticky-action probability 0.25, seed 7, one episode.
  • Pinned to Python 3.14 with a committed uv.lock; no ROM files or credentials ship in the repository.
  • Records RAM, frames, requests, responses and rewards to NPY/JSONL and renders GIFs at 2x game speed.
  • RAM and known room geometry are privileged information versus pixel-only Atari benchmarks; a seeded random policy is the local baseline.

Quickstart

bash
uv sync --locked --extra atari --extra recording
uv run --locked --no-env-file main.py --env CartPole-v1 --policy random

Watch out

Copy reviewed against the repo README on 2026-10-15; the README was truncated after the default-settings table, and GitHub metadata lists no licence. Atari runs depend on Arcade Learning Environment ROM setup, which the repository does not include, and raw recordings stay local.

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