Best alternatives to Open Mercato in 2026

Open Mercato is a foundation for building business software — a CRM, an ERP, an order management system — that arrives roughly 80% finished, so a developer starts from working multi-tenancy, permissions, and business modules instead of deciding those architectural questions from a blank file, the way a house-builder starts from a poured foundation instead of raw dirt. It's an open-source (MIT), TypeScript framework built on Next.js and PostgreSQL, with pre-built modules for sales, orders, catalog and pricing, plus multi-tenancy, role-based access control, and event-driven architecture already decided as conventions. Its distinguishing design choice is being explicitly built for AI coding assistants (Cursor, Claude Code, Codex) via structured specs and MCP support, so an AI agent can extend the app along existing patterns rather than re-deciding architecture each time.