Building a custom sync provider for real-time collaboration

WordPress 7.0 will introduce real-time collaboration in the block editor. Out of the box, the editor syncs changes between peers using an HTTP polling provider. However, an HTTP polling transport isn’t the only option and it may not be the best fit for your infrastructure, especially if you are a WordPress hosting provider.

The sync.providers client-side filter proposed for WordPress 7.0 lets you replace the default transport with your own. This post walks through why you’d want to use one, what a provider does, and how to build one.

Why build a custom provider?

The default HTTP polling provider is