gex.live rebuilds the SPX dealer options book from the 0DTE tape as it prints, second by second, rather than from the previous day's open-interest snapshot. Three books are published side by side: cumulative volume, open interest, and measured signed flow, so a desk can see where they disagree instead of trusting one number. The terminal marks the zero-gamma flip, the call and put walls, the upper and lower dealer hold band, and the gamma percentile against the prior twenty sessions, with DEX and VEX exposure and overlays for vanna, charm and 25-delta skew. More than a thousand finished sessions since April 2022 replay free with no account, so every level can be checked against history before subscribing to the live intraday stream. The LAB module turns a plain-English rule into a backtest over the full archive and returns an honest out-of-sample verdict. An MCP server exposes the same session data to AI assistants. There are deliberately no buy or sell signals.