How to Build a Multi-Vendor Marketplace with Medusa.js in 2026

Most ecommerce platforms were designed around a single-seller model. Adding multi-vendor capability on top of Shopify, WooCommerce, or Magento means layering third-party plugins that often conflict, create data silos, and impose serious limitations on how orders are split or how vendor payouts work. Medusa.js takes a fundamentally different approach.

The platform's modular architecture lets you define custom data models, link them to existing commerce primitives like products, orders, and inventory, and expose vendor-specific logic through custom API routes. The official Medusa Marketplace Recipe outlines how to create a Marketplace Module, register vendor data models, and use Medusa's workflow engine to handle the complex order-splitting logic that multi-vendor carts require.

Medusa is also the only open-source headless commerce platform with a dedicated marketplace platform page and a pre-built B2C marketplace starter (MercurJS by RigbyJS), which is already powering production marketplaces for enterprise clients. That combination of raw flexibility and production-proven starters makes Medusa.js the strongest foundation available for marketplace development in 2026.

Before touching any code, it is worth understanding the layers that make up a Medusa.js marketplace. Each layer has a clear responsibility, and keeping that separation clean is what makes the platform maintainable at scale.

The key architectural principle is module isolation. In Medusa.js, each module manages its own data and exposes its own service methods. To connect vendor data to existing commerce modules like products or orders, you use Medusa's Link Module system, which forms associations between data models across modules without breaking module isolation.

Start by creating a new Medusa project using the CLI. The installation command below sets up the Medusa application along with the optional Next.js storefront:

After installation, you will have a Medusa backend running on port 9000 and an admin dashboard accessible at localhost:9000/app. You will need PostgreSQL running locally or via a cloud provider before the application starts. Redis is also recommended for production-grade event handling and caching.

The Marketplace Module is the heart of your multi-vendor implementation. It contains custom data models for Vendor and VendorAdmin, and it links those models to Medusa's native product, order, and store entities.

Defining the Vendor Data Model

Create the module directory at src/modules/marketplace and define your Vendor model using Medusa's Data Model Language (DML). A basic Vendor model includes a unique handle, display name, contact email, and a relationship to VendorAdmin users who manage that vendor's operations.

The VendorAdmin model connects a Medusa User to a specific Vendor, allowing vendor staff to authenticate and access only their own products and orders. Medusa supports custom actor types, so vendor admins authenticate through a dedicated endpoint separate from the main admin login.

Linking Vendors to Products and Orders

Once the Vendor model is defined, you link it to Medusa's native Product and Order modules using defineLink. A module link forms a many-to-one association: each product belongs to one vendor, and each child order is linked to one vendor. These links enable Medusa's Query API to fetch vendor information alongside product or order data in a single request, without breaking module isolation.

Vendor admins need to authenticate and access their own data without touching the main Medusa admin. Medusa's custom actor type system handles this cleanly. You register a vendor actor type in your application, create a custom authentication API route at /auth/vendor, and issue JWT tokens specific to vendor sessions.

From there, you expose vendor-specific routes for managing products, viewing orders, and updating shipping profiles. Each route uses Medusa's middleware system to verify that the authenticated vendor only accesses data that belongs to them. This isolation is critical in a marketplace context, where data privacy between competing vendors is a non-negotiable requirement.

Order splitting is the most technically complex aspect of marketplace development. When a customer adds products from three different vendors to a single cart and completes checkout, the platform needs to split that single cart into three vendor-specific child orders, each with its own fulfillment workflow and payout calculation.

Medusa handles this through its Workflow engine. You replicate the native Complete Cart API route and replace it with a custom workflow that inspects the cart's line items, groups them by vendor, creates a child order for each vendor group, and links each child order back to the parent cart. Workflows in Medusa include automatic rollback mechanisms, so if one step in the order-splitting process fails, the entire transaction is safely reversed without leaving orphaned records.

The official Medusa documentation covers this pattern in detail under the Marketplace Recipe examples. The vendor example repository provides a full working implementation you can run locally before adapting it to your specific business logic.

Once orders are split, you need a payout mechanism that automatically routes funds to the correct vendor after a sale. Stripe Connect is the standard choice for this pattern. Each vendor onboards to your marketplace Stripe account as a connected account, and when an order is placed, Stripe's payment split logic routes the vendor's portion directly to their connected account while retaining your marketplace commission.

Medusa's payment module supports custom payment providers, so you implement Stripe Connect as a custom payment provider that is aware of the multi-vendor context. The provider receives the cart total, looks up the vendor accounts for each line item group, and issues separate payment intents or transfer instructions accordingly.

The MercurJS marketplace starter by RigbyJS includes pre-built Stripe Connect integration as part of its vendor payout system. If you want a head start rather than building payout logic from scratch, MercurJS is worth evaluating. Details are available at the Medusa marketplace platform page.

The default Medusa admin is a solid foundation, but a marketplace requires additional views that the standard admin does not provide out of the box. You need a vendor list page, a vendor detail view, tools to approve or suspend vendors, and commission reporting.

Medusa's admin is extensible through Widgets and UI Routes. Widgets let you inject custom React components into existing admin pages, for example adding a vendor attribution panel on the order details page. UI Routes let you add entirely new pages to the admin sidebar, such as a Vendors management page or a Marketplace Settings page.

For teams that want these marketplace admin features pre-built, the MercurJS starter includes vendor verification workflows, commission management, and super admin impersonation of vendor accounts for support purposes. The Mercur Seller Module also provides a pending invite system for onboarding new vendor team members securely.

Individual vendors need their own dashboard to manage their product catalog, view their orders, check their earnings, and update shipping profiles. The Medusa admin is a super admin tool and is not intended to be shared with vendors directly.

You have two options here. The first is to build a custom vendor dashboard using Next.js or React that consumes your vendor-specific API routes. This gives you complete control over the interface and user experience. The second option is to use the MercurJS vendor dashboard, which comes pre-built with product management, order tracking, and earnings views and is designed to connect directly to a Medusa.js backend.

Both approaches are valid. Teams with strong frontend capacity and unique vendor workflow requirements benefit from building a custom dashboard. Teams that want to launch quickly and iterate should start with the MercurJS starter and customize it over time.

The customer-facing storefront in a Medusa.js marketplace works exactly like a standard headless storefront, with the addition of vendor-specific features like vendor profile pages, filtered product listings by vendor, and vendor ratings or reviews if your business model requires them.

Medusa provides a Next.js Starter Storefront that you can deploy and customize immediately. It handles product listing, cart management, checkout, and customer accounts out of the box. For marketplace-specific customizations, you extend the storefront to pass vendor context through API calls and render vendor attribution on product and order pages.

If SEO is a priority for your marketplace, the Next.js storefront's server-side rendering capabilities ensure that product pages, category pages, and vendor profile pages are fully indexable by search engines. This is a significant advantage over client-rendered storefronts, particularly for marketplaces that rely on organic discovery to acquire both vendors and customers.

The right starting point depends entirely on how differentiated your marketplace model is. If you are building a straightforward buyer-seller platform in a niche category, MercurJS or the community marketplace plugin by Tech-Labi gives you a working foundation in days rather than months. If your marketplace has genuinely novel commission structures, complex product ownership rules, or deep ERP integrations, you will want to build from the official recipe so that your customizations are clean rather than layered on top of a starter's assumptions.

Before launching a marketplace to real vendors and customers, there are several infrastructure decisions that are easy to defer during development but become critical at scale.

• Database: PostgreSQL is the only fully supported production database for Medusa.js. Avoid SQLite beyond local development.

• Caching and events: Use Redis for both the event bus and in-memory caching. This is essential for handling concurrent cart operations across vendors without race conditions.

• File storage: Configure an S3-compatible storage provider for vendor product images. Medusa's file module abstracts storage, so switching providers later is straightforward.

• Vendor data isolation: Thoroughly test that vendor API routes cannot access other vendors' data. Authorization middleware must be applied consistently across every vendor-facing endpoint.

• Order rollback testing: Simulate payment failures during multi-vendor checkout to confirm that Medusa's workflow compensation logic rolls back all child orders cleanly.

The Askan Technologies team has published a detailed writeup on API-first architecture trade-offs that is highly relevant when designing the vendor API layer for a Medusa.js marketplace. You can read that at askantech.com/medusa-js-ecommerce-development-company.

Foraged is one of the most cited examples of a custom marketplace built on Medusa.js. It is a specialty food marketplace that required vendor-specific fulfillment rules, granular product metadata, and a customer experience that no existing marketplace template could have delivered. The Medusa team documented this case study as part of the Marketplace Recipe materials, and it remains a useful benchmark for what is achievable with the platform.

Patyna, another production marketplace built with the MercurJS starter by RigbyJS, demonstrates that the pre-built starter approach is also capable of powering serious commerce at scale. Both examples confirm that Medusa.js is not a theoretical framework. It is a production-proven infrastructure for multi-vendor commerce.

Building a multi-vendor marketplace with Medusa.js in 2026 is more accessible than it has ever been. The official recipe, the MercurJS starter, and the growing plugin ecosystem mean you are not starting from a blank canvas. The framework handles the hard problems of commerce data modeling, workflow rollback, and API-first extensibility so your team can focus on the business logic that actually differentiates your platform.

The decision that deserves the most care upfront is not which starter to use but how clearly you understand the vendor experience you want to create. Vendors who can onboard quickly, manage their catalog confidently, and trust that their data is isolated from competitors will stay on your platform and grow within it. Everything else is an implementation detail that Medusa.js is well equipped to handle.

If you are building a marketplace that sits adjacent to an existing tech stack involving ERP integrations or API-heavy microservices, it is worth reading the broader architectural thinking from Askan Technologies on headless commerce backend design. That context will help you make better decisions about where Medusa.js fits within your overall system before you write the first line of marketplace-specific code.