Medusa's Architecture

In this chapter, you'll learn about the architectural layers in Medusa.

HTTP, Workflow, and Module Layers#

Medusa is a headless commerce platform. So, storefronts, admin dashboards, and other clients consume Medusa's functionalities through its API routes.

In a common Medusa application, requests go through four layers in the stack. In order of entry, those are:

1. API Routes (HTTP): Our API Routes are the typical entry point.
2. Workflows: API Routes consume workflows that hold the opinionated business logic of your application.
3. Modules: Workflows use domain-specific modules for resource management.
4. Data store: Modules query the underlying datastore, which is a PostgreSQL database in common cases.

Database Layer#

The Medusa application injects into each module a connection to the configured PostgreSQL database. Modules use that connection to read and write data to the database.

Service Integrations#

Third-party services are integrated through commerce and architectural modules. You also create custom third-party integrations through a custom module.

Commerce Modules#

Commerce modules integrate third-party services relevant for commerce or user-facing features. For example, you integrate Stripe through a payment module provider.

Architectural Modules#

Architectural modules integrate third-party services and systems for architectural features. For example, you integrate Redis as a pub/sub service to send events, or SendGrid to send notifications.

Full Diagram of Medusa's Architecture#

The following diagram illustrates Medusa's architecture over the three layers.