Medusa vs commercetools vs Saleor - headless B2B in 2026

The 2026 headless market splits into three camps: open-source with code ownership (MedusaJS v2, Saleor), enterprise SaaS with annual licenses (commercetools) and vendor-hosted hybrids. For B2B the logo on a slide matters less than whether the engine supports contract pricing, credit limits, marketplace split checkout and ERP sync without waiting on a product roadmap.

commercetools is built over years in global programmes with dedicated SI partners. Saleor attracts GraphQL teams with strong product catalogues. MedusaJS v2 pairs modular Node.js architecture with the React/Next.js ecosystem - a natural stack when you already run JavaScript and want one API for web, mobile apps and integrations.

GMI Software delivers all three classes, but most often recommends Medusa when a mid-market client needs B2B with ERP and does not want GMV fees or enterprise license rent without a clear ROI.

Most Medusa, Saleor and commercetools comparisons look like feature matrices. The problem: features do not buy themselves. In B2B the expensive decisions are accountability decisions: who operates the engine, who writes integrations, who owns order lifecycle and how fast the business can change commercial rules.

commercetools communicates order-based pricing with no GMV fee and additional packages such as Connect, Frontend and InStore. That is a strong enterprise model, but it requires sales conversation, procurement and a partner who knows the ecosystem. It is not a “turn on a plan and build tomorrow” purchase.

Saleor Cloud publishes GMV thresholds and overage percentage, which helps early D2C and catalogue-heavy evaluation. Medusa communicates no GMV platform fee and code ownership. So the comparison must combine platform economics with team and integration cost.

B2B commerce is not “a shop with login”. It is per-customer and per-group price lists, MOQs, credit limits synced with ERP, sales-rep order approval and split checkout when a buyer fills a cart from many marketplace vendors.

MedusaJS v2 ships price list modules and an extensible order lifecycle - GMI adds NestJS integrations for credit balance sync, Redis caching and warehouse webhooks. Saleor needs similar custom work in GraphQL. commercetools offers B2B patterns out of the box, but every custom rule flows through expensive SI change requests.

When migrating from a monolith (Magento, legacy ERP portal), historical data matters too: orders, contract prices, company accounts. Open-source gives full control over migration scripts; enterprise SaaS often needs partner tooling priced separately.

Headless B2B TCO covers license or cloud plan, storefront and module development, ERP/PIM integrations, run-team cost and regulatory change work. Do not compare price tables only: in B2B the expensive parts are custom rules, data quality and speed of change after launch.

Medusa and Saleor move cost toward team and infrastructure while giving more code control. commercetools moves cost toward enterprise platform, partners and governance while reducing some operational responsibility for global organizations.

GMI practice: a Medusa v2 plus Next.js MVP lands at EUR 25,000 - 45,000; full B2B with ERP EUR 55,000 - 120,000. Annual run cost (hosting, monitoring, small iterations) is typically 15-25% of initial build. Saleor and Medusa are comparable on open-source TCO; the gap is team stack and onboarding time.