--- title: "Code Injection - Serpwise Documentation" description: "Inject custom CSS and JavaScript through the Serpwise gateway without touching your origin server or deploying code." url: "https://serpwise.ai/docs/code-injection/" source: "https://serpwise.ai/docs/code-injection/" --- [Back to Serpwise](/) Serpwise Documentation Connect · Configure · Execute Search documentation `/` No documentation found. ↑↓ Navigate Enter to open Browse documentation **Code Injection** lets you append global CSS and JavaScript to every HTML response served by the Serpwise gateway for a domain. It runs at the gateway layer, so changes apply instantly without a code deployment, CMS publish, or CDN purge on your origin. Common use cases: - Hide or restyle elements you can’t modify in your CMS (cookie banners, widgets, legacy footers) - Load third-party analytics, consent, or chat scripts globally - Add tracking pixels or deferred scripts without touching your theme - Override styles from a third-party tool embedded on every page * * * ## How It Works When a proxied HTML response is returned from your origin, the gateway applies code injection **before** evaluating rules: 1. If **CSS** is set, a `