LCEL chains are powerful but limited - they can’t loop, branch dynamically, or maintain complex state between steps. LangGraph solves this by modeling agent workflows as state machines: graphs where nodes are processing steps and edges define control flow. This explicit structure enables cycles, conditional routing, and persistent state that production agents require.
Building Agents with LCEL and Tool Integration
The LangChain Expression Language (LCEL) transforms how we build LLM workflows. Instead of managing execution flow manually, LCEL lets you compose components declaratively - like Unix pipes for AI. Combined with tool integration, LCEL enables building agents that reason and act in the real world.
Mastering LangChain and LangGraph - A Practitioner's Guide
If you’ve been building with LLMs, you’ve likely encountered the gap between simple API calls and production-ready agent systems. LangChain and LangGraph bridge that gap, providing the abstractions and patterns needed to build reliable, maintainable AI applications. This series takes you from LangChain fundamentals to production multi-agent systems, focusing on practical implementation over theory.
TIL: Setup MCP Server in Claude Code
Quick guide to add a Model Context Protocol (MCP) server to Claude Code CLI.