added endpoint for storefront (#1084)

docs/content/advanced/backend/endpoints/add-storefront.md

@@ -0,0 +1,176 @@
+---
+title: Add Endpoint for Storefront
+---
+
+# Add Endpoint for Storefront
+
+In this document, you’ll learn how to add a custom endpoint in the Backend that you can use from the Storefront.
+
+## Overview
+
+Custom endpoints reside under the `src/api` directory in your Medusa Backend. To define a new endpoint, you can add the file `index.js` under the `src/api` directory. This file should export a function that returns an Express router.
+
+Your endpoint can be under any path you wish. By Medusa’s conventions, all Storefront REST APIs are prefixed by `/store`. For example, the `/store/products` lets you retrieve the products to display them on your storefront.
+
+## Implementation
+
+To create a new endpoint, start by creating a new file in `src/api` called `index.js`. At its basic format, `index.js` should look something like this:
+
+```js
+import { Router } from "express"
+
+export default () => {
+  const router = Router()
+
+  router.get("/store/hello", (req, res) => {
+    res.json({
+      message: "Welcome to My Store!"
+    })
+  })
+
+  return router
+}
+```
+
+This exports a function that returns an Express router. In that function, you can create one or more endpoints. In the example above, you create the endpoint `/store/hello`.
+
+Now, if you run your server and send a request to `/store/hello`, you will receive a JSON response message.
+
+> Custom endpoints are compiled into the `dist` directory of your Backend when you run your server using `medusa develop`, while it’s running, and when you run `npm run build`.
+
+## Multiple Endpoints
+
+### Same File
+
+You can add more than one endpoints in `src/api/index.js`:
+
+```js
+router.get("/store/hello", (req, res) => {
+  res.json({
+    message: "Welcome to My Store!"
+  })
+})
+
+router.get("/store/bye", (req, res) => {
+  res.json({
+    message: "Come back again!"
+  })
+})
+```
+
+### Multiple Files
+
+Alternatively, you can add multiple files for each endpoint or set of endpoints for readability and easy maintenance.
+
+To do that with the previous example, first, create the file `src/api/hello.js` with the following content:
+
+```js
+export default (router) => {
+  router.get("/store/hello", (req, res) => {
+    res.json({
+      message: "Welcome to My Store!"
+    })
+  })
+}
+```
+
+You export a function that receives an Express router as a parameter and adds the endpoint `store/hello` to it.
+
+Next, create the file `src/api/bye.js` with the following content:
+
+```js
+export default (router) => {
+  router.get("/store/bye", (req, res) => {
+    res.json({
+      message: "Come back again!"
+    })
+  })
+}
+```
+
+Again, you export a function that receives an Express router as a parameter and adds the endpoint `store/bye` to it.
+
+Finally, in `src/api/index.js` import the two functions at the beginning of the file:
+
+```js
+import helloRoute from "./hello"
+import byeRoute from "./bye"
+```
+
+and in the exported function, call each of the functions passing them the Express router:
+
+```js
+export default () => {
+  const router = Router()
+
+  helloRoute(router)
+  byeRoute(router)
+
+  return router
+}
+```
+
+## Use Services
+
+Services in Medusa bundle a set of functionalities into one class. Then, you can use that class anywhere in your Backend. For example, you can use the `ProductService` to retrieve products or perform operations like creating or updating a product.
+
+You can retrieve any registered service in your endpoint using `req.scope.resolve` passing it the service’s registration name.
+
+Here’s an example of an endpoint that retrieves the count of products in your store:
+
+```js
+router.get('/store/products/count', (req, res) => {
+    const productService = req.scope.resolve('productService')
+
+    productService
+      .count()
+      .then((count) => {
+        res.json({
+          count
+        })
+      })
+  })
+```
+
+The `productService` has a `count` method that returns a Promise. This Promise resolves to the count of the products. You return a JSON of the product count.
+
+## Protected Routes
+
+Protected routes are routes that should be accessible by logged-in customers only.
+
+To make a route protected, first, import the `authenticate` middleware:
+
+```js
+import authenticate from '@medusajs/medusa/dist/api/middlewares/authenticate'
+```
+
+Then, add the middleware to your route:
+
+```jsx
+router.get('/store/products/count', authenticate(), (req, res) => {
+  //...
+})
+```
+
+Now, only authenticated users can access this endpoint.
+
+### Accessing Current Customer
+
+You can get the logged-in customer’s ID using `req.user`:
+
+```jsx
+const id = req.user.customer_id
+```
+
+To get the customer’s details, you can use the `customerService`:
+
+```jsx
+const id = req.user.customer_id
+const customerService = req.scope.resolve("customerService")
+
+const customer = await customerService.retrieve(id)
+```
+
+## What’s Next :rocket:
+
+- [Check out the API reference for all available endpoints.](https://docs.medusajs.com/api/store)

www/docs/sidebars.js

@@ -105,6 +105,18 @@ module.exports = {
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+              items: [
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+                  id: "advanced/backend/endpoints/add-storefront",
+                  label: "Add Endpoint for Storefront"
+                },
+              ]
+            },
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               id: "tutorial/adding-custom-functionality",