Custom Codes — Reference

The Custom Codes surface is the site-wide injection layer — the place where an operator drops a snippet of HTML, JavaScript, or third-party tag that should run on every page (or a defined subset) of the site. It is the last-resort surface for things the design system, the theme, and the page-level editors cannot express on their own — analytics tags, marketing pixels, support widgets, feature flags, custom font loaders, schema markup, scroll trackers.

This page is a reference for platform engineers and integrators. The Custom Codes surface is intentionally narrow — it lives separately from Custom CSS (which carries design-system styles) and from the page body sanitizer (which strips inline