How to share components among multiple extensions?

Extensions
1

Hello! This is my first time working with Shopify Plus and its architecture. My goal is to customize the new customer account area with several pages.

  1. I have created and installed an app.

  2. In the app, I’ve created “Customer account UI extensions” of the type “Full-page extension,” specifically using customer-account.page.render (I’m creating 1 extension per page).

I’m working with the latest API, 2025-10, which mandates the use of Polaris web components (This is my first time, and styling/layout has been tough, checking every single property in the documentation).

I’ve successfully created and displayed one page. The problems arose when I decided to create a /components directory outside the extension folders to reuse components across the app’s different extensions, but they are not being loaded.

Simplified structure:

myapp/
├─ app/
├─ extensions/
│  ├─ caui-page-main/
│  │  ├─ src/Main.jsx
│  ├─ caui-page-account/
│  │  ├─ src/Account.jsx
│  └─ extensions-components/
│     ├─ TextTest.jsx  ← Shared component

I’ve tried setting up a package.json to import it like this: import { TextTest } from '@myapp/extensions-components';

Simple component, TextTest.jsx:

JavaScript

import '@shopify/ui-extensions/preact';

export function TextTest() {
  return <s-text>Hi!</s-text>;
}

But it doesn’t work. Do you have any suggestions? I’m not sure how to approach this. Thanks.