What is hypernova?

Hypernova is an archived project from Airbnb that solved a specific problem: they had a backend server written in a language like Ruby or Python, and they wanted to render React components on the server before sending HTML to the browser, but Node.js was the only runtime that could actually execute React code. Hypernova solved this by running a small Node.js service as a sidecar, which the main server could send requests to whenever it needed a React component rendered to HTML. The way it works is that your main application server collects the data needed for a page, then sends an HTTP request to the Hypernova service with that data and the name of the component to render. Hypernova executes the JavaScript, produces an HTML string, and sends it back. The main server then embeds that HTML in the full page response. When the page reaches the browser, the JavaScript picks up where the server left off and makes the page interactive. This approach gives users faster page loads and better accessibility because the content is present in the HTML from the start, rather than being assembled in the browser after JavaScript loads. It also avoids the problem of maintaining two separate template systems, one for the server language and one for JavaScript. Hypernova includes client libraries for different server languages. The README shows examples using Ruby on Rails with the hypernova-ruby gem and React with the hypernova-react package. If the Hypernova service goes down or fails to render a component, the client libraries fall back to client-side rendering so the page still works. Note: Airbnb has archived this repository and is no longer maintaining it, as they no longer use this approach internally. The code remains available for reference or forking.