Every LLM app that wants to read a file, query a database, or call an API needs some way to describe that capability to the model and route the model's requests back to the right system. Before MCP, every vendor built that wiring differently. MCP is Anthropic's attempt at a …

A chain follows the map you drew. An agent draws its own.

LangChain gives you two ways to wire an LLM into a workflow: chains and agents. Both connect prompts, tools, and models into something useful, but the control flow works in opposite directions.

Chains: fixed routes

A chain is …

Claude Code is not a chatbot. It lives in your terminal, reads your actual files, writes code, runs commands, and executes multi-step workflows — all with your permission. Here are 30 concepts you need to understand it properly. No fluff, no hand-holding.

The 30 Concepts

1. The Terminal — Claude Code doesn't …