Adding Express Middlewares

Catalyst uses Express.js under the hood, allowing you to add custom middlewares in server/server.js.

Basic Setup

Export an addMiddlewares function that receives the Express app instance:

server/server.js

import express from "express";

export function addMiddlewares(app) {
  // Add your middlewares here
}

Examples

Serving Static Files

server/server.js

import express from "express";
import path from "path";

export function addMiddlewares(app) {
  app.use("/assets", express.static(path.join(__dirname, "../src/static")));
  app.use("/favicon.ico", express.static(path.join(__dirname, "../public/favicon.ico")));
}

Adding Custom Headers

server/server.js

export function addMiddlewares(app) {
  app.use((req, res, next) => {
    res.setHeader("X-Custom-Header", "value");
    next();
  });
}

Request Logging

server/server.js

import morgan from "morgan";

export function addMiddlewares(app) {
  app.use(morgan("combined"));
}

Authentication Middleware

server/server.js

export function addMiddlewares(app) {
  app.use((req, res, next) => {
    const token = req.headers.authorization;
    if (token) {
      req.user = verifyToken(token);
    }
    next();
  });
}

Middleware Order

Middlewares execute in the order they are added. Place authentication and logging middlewares before route handlers:

server/server.js

export function addMiddlewares(app) {
  // 1. Logging (runs first)
  app.use(morgan("combined"));

  // 2. Static files
  app.use("/assets", express.static("./public"));

  // 3. Authentication
  app.use(authMiddleware);

  // 4. Custom headers
  app.use(headerMiddleware);
}