SalesLedger: An AI-Augmented Business Operating System for Micro and Small Enterprises in Sub-Saharan Africa

Micro and small enterprises (MSEs) in sub-Saharan Africa constitute approximately 90% of all businesses and employ over 80% of the workforce, yet operate with severe digital infrastructure constraints and a fragmented software environment that typically requires owners to stitch together ten or more disconnected tools. This fragmentation imposes financial, cognitive, and compliance burdens that inhibit business growth, formalization, and access to credit. We present SalesLedger, an integrated business operating system designed for African MSEs that consolidates inventory management, point-of-sale, customer relationship management, AI powered storefront, tax compliance (Nigeria Tax Act, 2025), field agent management, and multi-gateway payment processing into a single platform deployable on commodity shared hosting. The system contributes: (1) an SQL-driven context architecture that achieved 100% factual accuracy on our structured-data validation set by replacing embedding-based retrieval with parameterized SQL via LLM tool calling; (2) an Encoded Response Protocol that bridges conversational AI with rich graphical interfaces without model-specific function calling dependencies; (3) multi-model AI routing with prompt caching that reduces cost by up to 85% through complexity-tiered model selection; and (4) a server-side time authority mechanism for anti-cheat enforcement in field agent networks. We evaluate the system on accuracy, cost, and tax compliance benchmarks and discuss its implications for MSE digital transformation in Africa.