Castle is a platform that helps small and medium-sized businesses automate bitcoin accumulation using everyday revenue. By connecting payment and bookkeeping platforms such as Shopify, Stripe, Square, and QuickBooks, Castle allows businesses to implement dynamic bitcoin purchasing strategies—including percentage-based buys, recurring purchases, and manual transactions. Users can set thresholds, manage treasury allocations, and generate reports to align bitcoin holdings with their financial goals. The platform is designed to operate in the background without disrupting daily operations or requiring staff training.