How We Built Oxygen: Hydrogen’s Counterpart for Hosting Custom Storefronts

In June, we shared the details of how we built Hydrogen, our React-based framework for building custom storefronts. We talked about some of the big bets we made on new technologies like React Server components, and the many internal and external collaborations that made Hydrogen a reality.  

This time we tell the story of Oxygen, Hydrogen’s counterpart that makes hosting Hydrogen custom storefronts easy and seamless. Oxygen guarantees fast and globally available storefronts that securely integrate with the Shopify ecosystem while eliminating additional costs of setting up third-party hosting tools. 

We’ll dive into the experiences we focused on, the technical choices we made to build those experiences, and how those choices paved the path for Shopify to get involved in standardizing serverless runtimes in partnership with leaders like Cloudflare and Deno.

Shopify-Integrated Merchant Experience

Let’s first briefly look at why we built Oxygen. There are existing products in the market that can host Hydrogen custom storefronts. Oxygen’s uniqueness is in the tight integration it provides with Shopify. Our technical choices so far have largely been grounded in ensuring this integration is frictionless for the user.

We started with GitHub for version control, GitHub actions for continuous deployment, and Cloudflare for worker runtimes and edge distribution. We combined these third-party services with first-party services such as Shopify CDN, Shopify Admin API, and Shopify Identity and Access Management. They’re glued together by Oxygen-scoped services that additionally provide developer tooling and observability. Oxygen today is the result of bundling together this collection of technologies.

A flow diagram highlighting the interaction between the developer, GitHub, Oxygen, Cloudflare, the buyer, and Shopify
Oxygen overview

We introduced the Hydrogen sales channel as the connector between Hydrogen, Oxygen, and the shop admin. The Hydrogen channel is the portal that provides controls to create and manage custom storefronts, link them to the rest of shop administrative functions, and connect them to Oxygen for hosting. It is built on Shopify’s standard Rails and React stack, leveraging Polaris design system for consistent user experience across Shopify-built admin experiences.

Fast Buyer Experience

Oxygen exists to give merchants the confidence that Shopify will deliver an optimal buyer experience while merchants focus on their entrepreneurial objectives. Optimal buyer experience in Oxygen’s context is a combination of high availability guarantees, super fast site performance from anywhere in the world, and resilience to handle high-volume traffic.

To Build or To Reuse

This is where we had the largest opportunity to contemplate our technical direction. We could leverage over a decade’s experience at Shopify in building infrastructure solutions that keep the entire Shopify platform up and running to build an infrastructure layer, control plane, and proprietary V8 isolates. In fact, we did briefly and it was a successful venture! However, we ultimately decided to opt for Cloudflare’s battle-hardened worker infrastructure that guarantees buyer access to storefronts within milliseconds due to global edge distribution.

This foundational decision significantly simplified upfront infrastructural complexity, scale and security risk considerations, allowing us to get Oxygen to merchants faster and validate our bets. These choices also leave us enough room to go back and build our own proprietary version at scale or a simpler variation of it if it makes sense both for the business and the users.

A flow diagram highlighting the interactions between the Shopify store, Cloudflare, and the Oxygen workers.
Oxygen workers overview

We were able to provide merchants and buyers the promised fast performance while locking in access controls. When a buyer makes a request to a Hydrogen custom storefront hosted at, that request is received by Oxygen’s Gateway Worker running in Cloudflare. This worker is responsible for validating that the accessor has the necessary authorization to the shop and the specific storefront version before routing them to the Storefront Worker that is running the Hydrogen-based storefront code. The worker chaining is made possible using Cloudflare’s new Dynamic Dispatch API from Workers for Platforms.

Partnerships and Open Source

Rather than reinventing the wheel, we took the opportunity to work with leaders in the JavaScript runtimes space to collectively evolve the ecosystem. We use and contribute to the Workers for Platforms solution through tight feedback loops with Cloudflare. We also jointly established WinterCG, a JavaScript runtimes community group in partnership with Cloudflare, Vercel, Deno, and others. We leaned in to collectively building with and for the community, just the way we like it at Shopify.

Familiar Developer Experience

Oxygen largely provides developer-oriented capabilities and we strive to provide a developer experience that cohesively integrates with existing developer workflows. 

Continuous Data-Informed Improvements

While the Oxygen platform takes care of the infrastructure and distribution management of custom storefronts, it surfaces critical information about how custom storefronts are performing in production, ensuring fast feedback loops throughout the development lifecycle. Specifically, runtime logs and metrics are surfaced through the observability dashboard within the Hydrogen channel for troubleshooting and performance trend monitoring. The developer-oriented user can extrapolate actions necessary to further improve the site quality.

A flow diagram highlighting the observability enablement side
Oxygen observability overview

We made very deliberate technical choices again on the observability enablement side. Unlike Shopify’s internal observability stack, Oxygen’s observability stack consists of Grafana for dashboards and alerting, Cortex for metrics, Loki for logging, and Tempo for tracing. Under the hood, Oxygen’s Trace Worker runs in Cloudflare and attaches itself to Storefront Workers to capture all of the logging and metrics information and forwards all of it to our Grafana stack. Logs are sent to Loki and metrics are sent to Cortex where the Oxygen Observability Service pulls both on-demand when the Hydrogen channel requests it.

The tech stack was chosen for two key purposes: Oxygen provided a good test bed to experiment and evaluate these tools for a potential long-term fit for the rest of Shopify, and Oxygen’s use case is fundamentally different from internal Shopify. To support the latter, we needed a way to separate internal-facing from external-facing metrics cleanly while scaling to the data loads. We also needed the tool to be flexible enough that we can provide merchants optionality to integrate with any existing monitoring tools in their workflows.

What’s Next

Thanks to many flexible, eager, and collaborative merchants who maintained tight feedback loops every step of the way, Oxygen is used in production today by Allbirds, Shopify Supply, Shopify Hardware, and Denim Tears. It is generally available to our Plus merchants as of June.

We’re just getting started though! We have our eyes on unlocking composable, plug-and-play styled usage in addition to surfacing deeper development insights earlier in the development lifecycle to shorten feedback loops. We also know there is a lot of opportunity for us to enhance the developer experience by reducing the number of surfaces to interact with, providing more control from the command line, and generally streamlining the Oxygen developer tools with the overall Shopify developer toolbox.

We’re eager to take in all the merchant feedback as they demand the best of us. It helps us discover, learn, and push ourselves to revalidate assumptions, which will ultimately create new opportunities for the platform to evolve.

Curious to learn more? We encourage you to check out the docs!

Sneha is an engineering leader on the Oxygen team and has contributed to various teams building tools for a developer-oriented audience.

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