Reaction Commerce — Open-Source Headless Commerce Platform

Introduction

Reaction Commerce is an open-source, API-first commerce platform built on Node.js. It exposes a GraphQL API that decouples the storefront from backend logic, letting teams build custom shopping experiences while relying on a proven order and catalog engine.

What Reaction Commerce Does

• Manages product catalogs with variants, pricing, and inventory tracking
• Processes orders through configurable fulfillment and payment workflows
• Provides a real-time GraphQL API for headless storefront integrations
• Supports multi-shop and marketplace architectures out of the box
• Handles tax calculation, discount rules, and shipping rate configuration

Architecture Overview

Reaction runs as a set of Node.js microservices behind a GraphQL gateway. The core services cover catalog, orders, accounts, and payments, each communicating through an internal event bus. MongoDB serves as the primary datastore. The platform is designed for containerized deployment with Docker, and the plugin system allows extending or replacing any core service.

Self-Hosting & Configuration

• Requires Docker and Docker Compose for local or production deployment
• Configure environment variables for MongoDB connection, SMTP, and payment providers
• Use the admin dashboard (Reaction Admin) for catalog and order management
• Extend with custom plugins by registering them in the plugin registry
• Production setups typically place the GraphQL API behind an API gateway or CDN

Key Features

• Headless architecture with a full GraphQL API for flexible frontend development
• Plugin-based extensibility for payments, shipping, taxes, and fulfillment
• Real-time data updates via GraphQL subscriptions
• Built-in support for multi-vendor marketplace configurations
• Role-based access control for admin and operator workflows

Comparison with Similar Tools

• Medusa — newer headless engine with modular architecture; Reaction has a more mature marketplace model
• Saleor — Python/Django-based with GraphQL; Reaction is Node.js-native
• Vendure — TypeScript-first with NestJS; Reaction uses a microservices approach
• Shopify — proprietary SaaS; Reaction is fully self-hosted and open source
• Spree — Ruby on Rails commerce; Reaction leverages the Node.js ecosystem

FAQ

Q: What database does Reaction Commerce use? A: MongoDB is the primary datastore. The platform uses MongoDB change streams for real-time event processing.

Q: Can I use any frontend framework with Reaction? A: Yes. The headless GraphQL API works with React, Next.js, Vue, or any client that can make GraphQL requests.

Q: Does Reaction support multiple storefronts from one backend? A: Yes. The multi-shop architecture allows separate catalogs, pricing, and fulfillment rules per shop.

Q: Is Reaction Commerce production-ready? A: Yes. It has been used in production by e-commerce businesses. Deployment is containerized and horizontally scalable.

Sources

• https://github.com/reactioncommerce/reaction
• https://reactioncommerce.com/docs