Seeed develops custom Medusa.js modules, storefronts, ERP integrations, and Square-connected commerce systems. It has run Medusa in production in three SaaS products: Cashless, Just Reservations, and WTZON.
Medusa.js v2 Development Agency
The team behind the Medusa v2 plugin with complete bidirectional Square sync on npm. Native v2 expertise from early access. Custom modules, marketplaces, ERP integrations, and storefronts.
Five Ways We Ship on Medusa
Custom Modules — Isolated v2 modules following MedusaService patterns. Subscription, marketplace, ERP, event commerce.
Third-Party Integrations — Square, DDI Advantix, Payload CMS, Algolia, GCP — connected via Medusa module links.
Storefronts + Admin UI — Next.js 15 storefronts plus custom Medusa Admin extensions with @medusajs/ui.
Five Types of Medusa Engagements
Custom Medusa Modules
Domain-specific commerce logic — event ticketing, subscription billing, vendor revenue splits, real-time ERP inventory — built as isolated v2 modules following the MedusaService pattern.
Third-Party Integrations
Square (medusa-square-plugin), DDI Advantix ERP, Payload CMS, Algolia/Meilisearch, SendGrid, GCP — connected via the module link system and workflow engine.
Multi-Vendor Marketplaces
Seeed's Rogue Commerce architecture powers WTZON. Multiple merchants list inventory; Seeed handles payment splitting and settlement through Square.
Storefront Development
Next.js 15 storefronts connected to Medusa's REST API. SSR product pages, ISR-cached catalog grids, Payload CMS editorial pages, Square checkout.
Admin UI Extensions
Custom panels and widgets built with @medusajs/ui and @tanstack/react-query that extend the Medusa Admin dashboard with client-specific workflows.
Square Medusa Integration: @weareseeed/medusa-square-plugin
Square OAuth + Bidirectional Catalog Sync — Merchants connect their Square account; products and inventory stay in sync across systems.
Web Payments SDK — Credit card, Apple Pay, Google Pay, Cash App Pay. PCI scope isolated via GCP Cloud Run microservice.
Medusa Admin UI Extension — Configure Square locations, view sync status, and trigger reconciliation directly from the Medusa Admin.
Why Medusa v2 Architecture Matters
Customization Without Forking
v1 required modifying core Medusa files for customization. In v2, you write a custom module that extends or replaces default behavior — core stays untouched.
Selective Module Use
Use Medusa's Catalog module only while keeping your existing order management. v2 modules compose selectively — adopt incrementally without rip-and-replace.
Workflow Engine
StepResponse workflows handle complex multi-step operations (multi-vendor checkout with split settlement) with built-in retry logic and compensation steps. No external queue infrastructure needed.
Frequently Asked Questions
Common questions about Medusa.js v2 development with Seeed.
Weighing a move
to Medusa?
Read our decision guide: when to migrate from Shopify Plus or Magento, what moves, and how a phased migration keeps the store selling.
Build on Medusa.js with Seeed
The team behind the Medusa v2 plugin with complete bidirectional Square sync. Let's talk about your project.
medusa-square-plugin authors
Complete bidirectional Square sync for Medusa v2, published on npm.
v2 native from early access
No v1 carry-over. Built on the new module architecture.
Production proven
Three SaaS products run on Seeed's Medusa stack.
ERP integration depth
DDI Advantix in production. NetSuite and QuickBooks pattern ready.
Build on Medusa.js with Seeed
The team behind the Medusa v2 plugin with complete bidirectional Square sync. Let's talk about your project.
medusa-square-plugin authors
Complete bidirectional Square sync for Medusa v2, published on npm.
v2 native from early access
No v1 carry-over. Built on the new module architecture.
Production proven
Three SaaS products run on Seeed's Medusa stack.
ERP integration depth
DDI Advantix in production. NetSuite and QuickBooks pattern ready.
