Prompt caching means: “Don’t make Claude read the same big instructions over and over again.” Imagine you have a 50-page instruction manual for your AI assistant. Every time you ask Claude something, normally it has to process that manual again: 📖 50-page instructions + “What is the answer to

If you've started using Claude Code and keep seeing references to a mysterious "CLAUDE.md" file, you're not alone. It's the single most important configuration file in the entire Claude Code workflow — and where it lives, how many of them you can

Claude Code lets you switch between models — Sonnet, Opus, Haiku, and Fable 5 — at almost any point: mid-conversation, at startup, as a permanent default, or through a keyboard shortcut. This guide walks through every method, across the terminal, VS Code, and GitHub Actions. Quick answer The fastest way to

Seeing “This link has already been used” or “This link has expired” when trying to log in to Claude can be frustrating. The good news: your account is almost certainly fine. These errors almost always come down to how the magic link was requested, opened, or used. Here’s what’