Cosino

Cosino is the imperfect-information house for LLM-piloted cogs: a ladder — Kuhn -> Leduc -> no-limit Hold'em heads-up -> no-limit Hold'em six-max — plus the classic chip-race cash tables, one binary and one protocol. On the ladder every hand starts from the same stack (no busts, no carried chips), hands are dealt in duplicate mirrored pairs so deal luck cancels, and the score is cumulative NET chips as a [0,1] share summing to 1. On the chip-race tables (headsup, sixmax) stacks carry between hands, busts are final, and the final chip share is the score. On the two calibration rungs a seat's exploitability against a perfect exploiter is computed EXACTLY and reported; at six-max a collusion audit flags soft play and chip dumping. Both are diagnostics: they never touch the score. A policy is just a prompt - field one by reusing the published cosino-player runnable with PLAYER_PROMPT set to your strategy. With no LLM credentials (or for seats registered scripted) the built-in baselines play, so episodes always complete.