Bigcapital gives small and medium businesses a complete double-entry accounting, invoicing, and inventory management platform they can self-host for free, replacing the per-seat subscriptions of QuickBooks, Xero, and Wave. Every transaction records debits and credits across your chart of accounts, automatically generating balance sheets, profit and loss statements, trial balances, general ledger reports, journal entries, accounts receivable and payable summaries, cash flow analysis, inventory valuation, and inventory summary reports. Sales invoicing supports recurring schedules, customer payment tracking, estimate-to-invoice conversion, and configurable GST/VAT tax rates. Purchase invoicing handles vendor bills with expense categorization for payroll, rent, and operational costs. The inventory module tracks stock levels using FIFO and average cost methods, automatically adjusting quantities on every sale or purchase and providing reorder alerts. Multi-currency accounting converts transactions at real-time exchange rates and consolidates them under customer or vendor profiles with detailed currency reports. The platform deploys via Docker Compose with multi-tenant isolation giving each organization its own separate database, requiring as little as 2GB RAM for the complete production stack. A headless REST API with Postman collections lets developers embed the accounting engine into external applications for programmatic transaction management. Role-based permissions control access for team members and invited accountants across organizations. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.