Medusa

The leading open-source headless commerce framework, with a paid managed cloud option

Best for: Developers building a fully custom commerce backend/storefront who want an open-source, self-hostable alternative to Shopify with multi-warehouse and multi-region support.
Skip if: You want a simple themed store rather than a headless build-your-own-frontend commerce framework.

Medusa is an open-source, TypeScript/Node.js headless commerce framework for building custom storefronts and commerce backends. It supports multi-warehouse inventory, multiple sales channels, multi-region pricing/tax/currency, a promotion engine, and a customizable admin dashboard, plus MCP integration for AI agents. The core framework is free and self-hostable on GitHub; Medusa also offers a managed cloud starting at $29/month for teams that don't want to run their own infrastructure.

Pros

Free, open source, and self-hostable with no GMV tax if you run it yourself
One of the most active open-source commerce projects on GitHub with real enterprise adopters (Eight Sleep, Heineken)
Handles complex commerce needs (multi-warehouse, multi-region, promotions) that simpler starters skip

Cons

Headless architecture means you still have to build or wire up your own storefront frontend
More setup and infrastructure decisions than a hosted platform like Shopify
Managed cloud pricing adds up for higher-traffic stores beyond the base $29/month tier