Middleware

Composable request processing with middleware functions.

Work in Progress

This page is under construction. More detailed documentation coming soon.

Overview

Middleware functions are executed before your handler, allowing you to:

• Authenticate requests
• Log requests
• Validate input
• Transform data
• Handle CORS

const authMiddleware = (req, res, next) => {
  if (!req.headers.authorization) {
    res.status(401).json({ error: 'Unauthorized' });
    return;
  }
  next();
};

export const handler: Handler = [authMiddleware, (req, res) => {
  res.json({ protected: 'data' });
}];

Built-in Middleware

CORS

import { cors } from '@gati-framework/runtime';

export const handler: Handler = [
  cors({
    origin: '*',
    methods: ['GET', 'POST'],
    credentials: true
  }),
  (req, res) => {
    res.json({ ok: true });
  }
];

Creating Middleware

export const logger = (req, res, next) => {
  console.log(`${req.method} ${req.url}`);
  next();
};

export const requireAuth = (req, res, next) => {
  const token = req.headers.authorization;
  if (!token) {
    res.status(401).json({ error: 'Unauthorized' });
    return;
  }
  // Verify token...
  next();
};

Related

• Handler API - Handler function signature
• CORS Guide - CORS configuration