Live commerce, flash sales, and ticketing create attribution challenges that invalidate standard 30-day window models. This paper presents a real-time multi-touch attribution framework optimized for high-velocity commerce, featuring sub-second event ingestion, time-decay weighting with velocity adjustments, and urgency-aware conversion modeling. The framework handles microsecond purchase decisions while maintaining causal integrity and Shapley-fair channel credit allocation. Extends Robinson (2026a) to live event contexts.