I'd be happy to draft a training material for your developers to gain hands-on experience with Shopify-specific concepts. This material will guide them through creating a working Shopify app that demonstrates webhooks, app_proxy, and checkout extensibility. The app will be built using Next.js and can be hosted locally and served through ngrok.

Let's break this down into a step-by-step guide:

1. Setting up the development environment
2. Creating a basic Next.js app
3. Implementing Shopify authentication
4. Working with Shopify webhooks
5. Implementing app_proxy
6. Exploring checkout extensibility
7. Testing the app locally with ngrok

Let's start with the setup and basic app creation:

Now that we have our basic app structure, let's go through the training material step by step:

1. Setting up the development environment:

   • Install Node.js and npm
   • Install the Shopify CLI: npm install -g @shopify/cli @shopify/cli-hydrogen
   • Create a new Shopify partner account and create a new app in the partner dashboard

2. Creating a basic Next.js app:

   • Run npx create-next-app@latest shopify-training-app
   • Navigate to the app directory: cd shopify-training-app
   • Install necessary dependencies: npm install @shopify/shopify-api

3. Implementing Shopify authentication:

   • Create the pages/api/auth.ts and pages/api/auth/callback.ts files as shown above

   • Set up environment variables in a .env.local file:

     API_KEY=your_api_key API_SECRET_KEY=your_api_secret_key SCOPES=read_products,write_products HOST=https://your-ngrok-url.ngrok.io

4. Working with Shopify webhooks:

   • Create the pages/api/webhooks.ts file as shown above
   • Register webhooks in your Shopify app settings in the partner dashboard
   • Test webhook reception by creating a product in your development store

5. Implementing app_proxy:

   • Create the pages/api/proxy.ts file as shown above
   • Set up app proxy in your Shopify app settings in the partner dashboard
   • Test the app proxy by making a request to your proxy URL

6. Exploring checkout extensibility:

   • Create a new checkout UI extension using the Shopify CLI:

     shopify hydrogen extension create
   • Choose "Checkout UI" as the extension type
   • Implement the extension as shown in the checkout-ui-extension/src/index.jsx file above
   • Use the Shopify CLI to push and publish your extension

7. Testing the app locally with ngrok:

   • Install ngrok: npm install -g ngrok
   • Start your Next.js app: npm run dev
   • In a new terminal, start ngrok: ngrok http 3000
   • Update your app URL and allowed redirection URL in the Shopify partner dashboard with your ngrok URL
   • Test your app by installing it on a development store

Throughout this process, encourage developers to:

• Read the Shopify API documentation for each concept
• Experiment with different API endpoints and webhook topics
• Implement error handling and logging
• Consider security best practices, such as validating webhook signatures

This hands-on approach will give your developers practical experience with key Shopify concepts while building a functional app. They'll learn how to authenticate with Shopify, handle webhooks, implement app proxies, and extend the checkout process.

Remember to provide ample time for questions and troubleshooting during the training. It might also be beneficial to set up a shared repository where developers can commit their progress and collaborate.

Is there any specific area you'd like me to expand on or any additional Shopify concepts you'd like included in this training material?