Verifier card — reverse_text · grade A

Clean — no reward-hack signature found; the reward held against the full battery below.

• source: prime-hub · grader: deterministic* · verifiers: 0.1.14 · pass_threshold: 0.5 · rows: 3
• seal: record_sha256:4f7551d5041802b7 — re-running this audit reproduces it byte-for-byte

What we tested

• Degenerate-probe — 24 content-free completions: all below pass_threshold ✓
• IPT invariance — invariant under cosmetic re-rendering ✓
• Verifier-completeness — abstained (no usable scalar ground-truth answer)

What we found

• No reward-hack signature. Every degenerate probe scored below pass_threshold (0.5); the reward was invariant under cosmetic re-rendering; and the exploit-search (where run) found no accepted non-attempt. A defended reward.

Reproduce

stardata audit reverse_text --row-seed 0

Coverage & limitations

• grader class audited: deterministic (inferred from the replayable reward)
• instruments run: degenerate-probe, IPT invariance, verifier-completeness
• scope: an environment-side audit of reward gameability — it does not guarantee your policy won't find other optimizations, nor does it assess task difficulty (a separate difficulty certificate).