arena/README.md

Arena

RL environments from Lumbridge. Apache-2.0, built to the verifiers v1 spec so they install and run on the Prime Intellect Environments Hub unchanged.

An environment here is an eval you take the gradient of. That is not a rename — it changes what the artifact has to carry. A benchmark's score is its output, so a benchmark can be a number in a table. An environment's score is the input to the next weight update, so it has to be reproducible, gameable-proof, and traceable back to the code that produced it, or the model that trained on it inherits whatever was wrong with it silently.

Three rules follow, and every environment in this repository is held to them:

1. Graded on what the model did not see. Rules, plans and policies fitted to visible examples pass on visible examples. If a held-out slice cannot be generated, the environment does not measure generalisation and does not ship.
2. No single-sided reward. Every reward has a counterweight in the same episode. A reward you can max by doing the crude thing is a reward that teaches the crude thing.
3. A reachable ceiling and a zero floor, demonstrated. Each environment ships the check that shows an oracle scores 1.0 and inaction scores 0.0. An unreachable component is dead weight in the gradient; a floor above zero pays for doing nothing.

Environments

redaction-pressure	Write redaction rules for a ticket corpus. Source-character provenance makes partial edits residual secrets, while the clean gate requires character-for-character preservation of all non-secret source content. Hostile regexes share one episode budget.

Running one

uv run --project environments/redaction_pressure eval @ configs/redaction_pressure.toml --model <model-id>

Run its release gate from the repository root:

uv lock --project environments/redaction_pressure --check
uv sync --project environments/redaction_pressure --frozen
uv run --project environments/redaction_pressure \
  python -m unittest discover -s environments/redaction_pressure/tests -v

Why these, and not benchmark reimplementations

The Hub is filling with reimplementations, which are worth doing and are not what we have. What Lumbridge has is a set of tools aimed at verifiable work. Those gates make good rewards only after their ceiling, floor, adversarial cases, and replay identity are committed beside the environment. redaction-pressure is the first small contract for that path; Bench/Forge integration remains future work rather than an implied dependency.