What is Reaction Commerce used for?

Reaction Commerce, later Mailchimp Open Commerce, an API-first headless commerce platform on Node.js, MongoDB, and GraphQL that has been discontinued. It is a good fit for studying headless commerce architecture and forking as a base for a custom storefront back end.

Is Reaction Commerce open source?

Yes. Reaction Commerce is open source under the GPL-3.0 licence. Its source code is on GitHub at reactioncommerce/reaction and is written mainly in JavaScript.

Is Reaction Commerce free?

Yes. Reaction Commerce is open source, so the software itself is free to use.

Can I self-host Reaction Commerce?

Yes. Reaction Commerce can be self-hosted on your own server or infrastructure; there is no official hosted version.

What is Reaction Commerce an alternative to?

Reaction Commerce is an open-source alternative to commercetools and BigCommerce. Other open-source alternatives to commercetools include Medusa, Vendure and Virto Commerce.

Is Reaction Commerce actively maintained?

The most recent commit to Reaction Commerce was on 1 March 2026, and the latest release is v5.0.0, published on 13 June 2023. The project has 12k stars on GitHub.

Reaction Commerce: open-source alternative to commercetools

About Reaction Commerce

Reaction, formerly Reaction Commerce and later Mailchimp Open Commerce, is an API-first, headless commerce platform built with Node.js, React, MongoDB, and GraphQL. It runs with npm, Docker, and Kubernetes. The repository tagline states that the project has been discontinued, so it should be treated as archived code, not a maintained product. It is released under the GPL-3.0 license.

While it was active it offered a plugin system for choosing integrations, multi-tenant hosting of several shops in one installation, products with options and variants, and an architecture designed to scale from one server to hundreds. The README claimed fast GraphQL queries and use on sites processing tens of thousands of orders a day.

Today it is mostly useful as a reference for headless commerce architecture or as a starting point for teams willing to maintain a fork. Anyone planning a new store should look at actively maintained alternatives.

Key features

API-first headless commerce architecture
GraphQL API on Node.js and MongoDB
Plugin system for integrations
Multi-tenant shops in one installation
Products with options and variants
Docker and Kubernetes deployment

Good fit for

→Studying headless commerce architecture
→Forking as a base for a custom storefront back end

Built with: JavaScript; Docker; MongoDB; GraphQL
Tags: ecommerce; headless-commerce; graphql; nodejs; mongodb; discontinued; api-first; marketplace

Reaction Commerce: questions and answers

What is Reaction Commerce used for?: Reaction Commerce, later Mailchimp Open Commerce, an API-first headless commerce platform on Node.js, MongoDB, and GraphQL that has been discontinued. It is a good fit for studying headless commerce architecture and forking as a base for a custom storefront back end.
Is Reaction Commerce open source?: Yes. Reaction Commerce is open source under the GPL-3.0 licence. Its source code is on GitHub at reactioncommerce/reaction and is written mainly in JavaScript.
Is Reaction Commerce free?: Yes. Reaction Commerce is open source, so the software itself is free to use.
Can I self-host Reaction Commerce?: Yes. Reaction Commerce can be self-hosted on your own server or infrastructure; there is no official hosted version.
What is Reaction Commerce an alternative to?: Reaction Commerce is an open-source alternative to commercetools and BigCommerce. Other open-source alternatives to commercetools include Medusa, Vendure and Virto Commerce.
Is Reaction Commerce actively maintained?: The most recent commit to Reaction Commerce was on 1 March 2026, and the latest release is v5.0.0, published on 13 June 2023. The project has 12k stars on GitHub.