RetainAI bundles three retention engines for small Shopify stores: AI-written abandoned cart recovery, post-purchase review request emails, and one-click loyalty with auto-issued Shopify discount codes. Built for stores that would otherwise install three separate apps for these jobs. Every recovery email is written by Claude AI using the customer's name and the line items in their cart. Billing runs through Shopify's appSubscriptionCreate API. No theme edits, no Liquid changes, no new logins.