Socket

Authentication and the Handshake

Understand the Socket.IO handshake process and how to securely authenticate clients using the auth payload, middleware, and token renewal on reconnect.

Building a Chat Application

Learn how to design a real-time chat app with Socket.IO, covering rooms, broadcasting, message persistence, and delivery guarantees.

Debugging Socket.IO

Tools and techniques for diagnosing connection failures, dropped events, and scaling bugs in Socket.IO apps.

Error Handling in Socket.IO

Learn the distinct categories of Socket.IO errors — connection errors, disconnect reasons, and acknowledgement failures — and how to handle each robustly.

Middleware in Socket.IO

Learn how Socket.IO middleware intercepts connections and packets, enabling authentication, logging, and rate limiting before your event handlers ever run.

Namespaces in Socket.IO

Understand how namespaces partition a single Socket.IO server into independent communication channels, each with its own middleware, event handlers, and connec…

Real-Time Notifications

Design a reliable real-time notification system with Socket.IO using per-user rooms, namespaces, and durable fan-out for offline users.

Socket.IO Best Practices

Practical patterns for structuring, scaling, and maintaining production Socket.IO applications.

Socket.IO Interview Questions

Common interview questions on Socket.IO internals, scaling, and design trade-offs, with model answers.

Socket.IO Quick Reference

A condensed cheat sheet of core Socket.IO APIs, events, and configuration options for day-to-day use.

Socket.IO vs WebSockets

A comparison of Socket.IO's higher-level abstraction against the raw WebSocket API/protocol, covering compatibility, features, and when to choose each.

Socket.IO with React

Integrate Socket.IO cleanly into React using a context provider, custom hooks, and correct connection lifecycle management.

Socket.IO with TypeScript

Learn how to add end-to-end type safety to Socket.IO applications using event-map generics for server-to-client, client-to-server, and inter-server events.

Testing Socket.IO Apps

Write reliable integration and unit tests for Socket.IO features using real servers, real clients, and targeted mocking strategies.

The Socket.IO Adapter

Learn what the Socket.IO adapter is, how it powers rooms and broadcasting under the hood, and why the default in-memory adapter breaks down once you run more t…

What Is Socket.IO?

Socket.IO is a JavaScript library that enables low-latency, bidirectional, event-based communication between web clients and servers, built on top of the Engin…

Your First Socket.IO Server

A hands-on walkthrough of building and running a minimal Socket.IO server with Express, handling connections, custom events, and disconnections.

Socket.IO Explained

Understand what Socket.IO adds on top of raw WebSockets — rooms, namespaces, automatic reconnection, and transport fallback — and when it's the wrong tool for…

Socket Programming Basics

Learn how sockets provide the programming interface for network communication, using Python's socket module to build a minimal TCP client and server.