How to create an Express router — Basic

Server Architecture / Routes Building routes

Instantiate Router(), wire handlers, and export the router for mounting on the app.

Learn: An Express Router is a mini-app: it has its own middleware stack and routes, then mounts on the main app. `mergeParams: true` lets nested routers see parent params (e.g. `:userId` from a parent mount). Always export the router for `app.use`.

Supplementary examples

Router module skeleton

const router = require("express").Router({ mergeParams: true });

// routes here

module.exports = router;

Mount in app.js

const pastesRouter = require("./pastes/pastes.router");
app.use("/pastes", pastesRouter);

Course example

const router = require("express").Router({ mergeParams: true });

Additional references & examples

Express Router API
Router methods, route parameters, and mounting paths.
Express.js guide
Routing, middleware order, and request/response lifecycle.
Thinkful — Organizing Express (pastes example)
Router/controller structure demonstration project.