From the OpenReplay Blog
MCP Apps: Adding Interactive UI to AI Conversations
MCP Apps enable interactive UI components inside AI conversations. See how MCP servers render dashboards and forms using the ext-apps SDK standard.
A Better Way to See Errors in VS Code with Error Lens
Error Lens brings ESLint and TypeScript diagnostics inline in VS Code, helping frontend developers spot and fix errors faster without leaving the editor.
Building Your First API with Koa
Build a REST API with Koa by setting up routing, parsing JSON bodies, and applying the middleware cascade model to handle GET and POST endpoints.
When to Use user-select: none (and When It's a UX/Accessibility Trap)
Know exactly when CSS user-select none helps interactive controls and when it harms accessibility, translation tools, and users who rely on text selection.
How to Measure JavaScript Performance
Profile JavaScript execution with DevTools, the Performance API, and Core Web Vitals to identify bottlenecks and measure real user INP accurately.
Virtual Scrolling for High-Performance Interfaces
Virtual scrolling renders only visible DOM nodes, keeping large datasets fast. See how windowing, overscan, and libraries like TanStack Virtual work.
OpenClaw: A New Open-Source AI Assistant
OpenClaw is a self-hosted AI agent that executes shell commands, controls browsers, and integrates with Slack, Telegram, and WhatsApp on your own hardware.
Streams Explained for Web Developers
Process fetch responses chunk by chunk using the Web Streams API, ReadableStream, and TransformStream to reduce memory pressure and improve performance.
How Key-Value Databases (e.g., Redis, Memcached) Work
Redis, Memcached, and key-value databases use in-memory hash tables for fast lookups, caching, and session storage in frontend-facing backend systems.
What Is Lynx.js? A Beginner's Guide
Lynx.js is a cross-platform framework from ByteDance that renders native iOS and Android UIs using React, real CSS, and a dual-thread architecture.
Absolute Values in CSS with abs()
The CSS abs() function handles signed custom properties safely in spacing, animation timing, and layout math without requiring JavaScript workarounds.
Building Type-Safe API Clients with OpenAPI and TypeScript
Generate TypeScript types from OpenAPI specs using openapi-typescript, openapi-fetch, and Orval to build type-safe API clients and eliminate runtime errors.
Implementing Binary Search in JavaScript
Implement iterative and recursive binary search in JavaScript, learn the sorted array requirement, and decide when binary search outperforms linear search.
Linux Text Processing Cheat Sheet
Boost terminal productivity with grep, sed, awk, ripgrep, and jq to parse log files, extract columns, and transform structured text data efficiently.
How CSS Aspect Ratio Works
CSS aspect-ratio controls box sizing, replaces the padding hack, and prevents layout shift when paired with object-fit in flexbox and grid layouts.
How to Implement Toast Notifications in Vue
Build Vue 3 toast notifications using a custom composable or libraries like Vue Toastification, with accessible markup and Composition API patterns throughout.
Caching Basics Every Web Developer Should Know
Build faster web applications by applying browser cache, CDN cache, Cache-Control headers, ETag, and Last-Modified validation techniques correctly.
Showing Human-Readable Time in the Browser
Format UTC timestamps for browser display using Intl.DateTimeFormat, Intl.RelativeTimeFormat, Intl.DurationFormat, and Temporal without third-party libraries.
CSS Grid Lanes: The New Native Masonry Layout
Native CSS Grid masonry layout, browser support status, and fallback strategies for building Pinterest-style layouts without JavaScript libraries.
How to Handle Uncaught (in promise) TypeError
Fix Uncaught in promise TypeError by applying try catch blocks, dot catch handlers, and the unhandledrejection event for browser Promise error handling.
The Best Git UIs for Developers
Compare Fork, GitKraken, Tower, Sourcetree, GitButler, and Lazygit to choose the right Git UI for branching, rebasing, and conflict resolution workflows.
What's the Difference Between Map, Set, and Object in JavaScript?
Compare Map, Set, and Object in JavaScript to choose the right data structure based on key handling, iteration order, and performance characteristics.
Using Git Subrepos to Manage Large Codebases
Compare Git subrepo, Git submodules, and Git subtree for managing shared code across large codebases and select the right vendoring workflow for your team.
How to Self-Host Google Fonts in WordPress
Host Google Fonts locally in WordPress via the Font Library, manual WOFF2 upload, or plugins to remove third-party connections and improve GDPR compliance.