E-commerce AI in 2026 is the practice of building production AI for personalization, voice commerce, WISMO (where-is-my-order) chatbots, listing generation, and on-device search in mobile shopping apps. Unlike marketing personalization tools (Segment, mParticle) which segment audiences and trigger campaigns, e-commerce AI lives inside the purchase funnel itself, ranking products, drafting answer copy, and acting through cart and order systems. Unlike lexical-only site search, AI search uses hybrid retrieval, intent classification, and grounded answer synthesis to handle queries like "the navy puffer in size M under $200" that pure keyword match misses. Common integration points include Shopify Admin, Aftership for WISMO, Klaviyo, OMS and 3PL APIs, and Algolia for hybrid retrieval. Workflows include voice copilots in mobile, AI listing generators, support deflection bots, and cart-recovery agents. Compliance maps to CCPA/CPRA for personalization data, FTC endorsement and AI-generated-content guidance for listing copy, and PSD2/SCA where checkout flows touch EU buyers.