Server Routes Differences with PWA Kit

PWA Kit server routes are typically centralized as Express handlers in SSR server code. Storefront Next replaces that with file-based resource routes and loader/action handlers using standard Web Request/Response APIs. This distributes server behavior across route modules and aligns API endpoints with routing conventions.

Aspect	PWA Kit	Storefront Next
Pattern	Express routes in `ssr.js`	File-based resource routes
Configuration	Centralized in one file	Distributed across route files
Request API	Express `req`/`res` objects	Web Standard `Request`/`Response`
Route Definition	`app.get('/path', handler)`	Export `loader`/`action` from file
Dynamic Routes	Express params (`/:param`)	File naming (`$param`)
Middleware	Express middleware chain	React Router middleware exports
Client Execution	Server only	Optional `clientLoader`/`clientAction`

Both support GET (loaders) and POST/PUT/DELETE (actions).
Both can set cache headers and response status codes.
Both integrate with SLAS for authentication callbacks.
Both can proxy Commerce API calls.
Both support dynamic route parameters.

Keep these tips in mind when you convert your PWA Kit storefront to Storefront Next.

Route extraction: Move logic from ssr.js callbacks into separate route files.
Request handling: Convert Express req.body/req.query to request.json()/URL.searchParams.
Response handling: Convert res.json() to Response.json().
Middleware: Use React Router middleware exports instead of Express middleware.
Client-side option: Consider adding clientLoader for endpoints that can run on the client.