[relaybell docs › Install › Installing the SDK](https://relaybell.com/docs/install) · [All docs as Markdown](https://relaybell.com/docs.md) · [Index for AI assistants](https://relaybell.com/llms.txt)

# Installing the SDK

> Hosting the service worker (sw.js, swPath, swScope), apiBase, and the iPhone/iPad Home Screen rule.

The SDK needs a service worker on your own domain. The default `swPath` is `/sw.js` — host our [sw.js](https://relaybell.com/sw.js) there, or put it somewhere else on the same domain and pass that path as `swPath` (for example `"/folder/sw.js"`). The [WordPress plugin](https://relaybell.com/docs/install-wordpress) serves its own service worker, so there's no file to upload. Shopify doesn't let you upload this file — see [Shopify](https://relaybell.com/docs/install-shopify).

**Already have a service worker at `/sw.js`** (a PWA, for example)? Keep it, and host relaybell's `sw.js` in its own folder with `swPath` and `swScope` (for example `"/relaybell/sw.js"` and `"/relaybell/"`). A worker with a narrower scope still receives push, so the two don't clash.

`apiBase` is the relaybell address the SDK talks to. If you leave it out, the SDK uses the address it was loaded from — `https://relaybell.com` for the snippet above — so the snippet works either way.

> **Note:** On **iOS/iPadOS**, web push only works once a visitor adds your site to their Home Screen (Apple's rule). The SDK detects iOS and shows an "Add to Home Screen" hint automatically.