03. Modern Stack: ReAct with LangChain

Comparing the "From Scratch" ReAct implementation with LangChain.

In 01_react_scratch, we built an agent loop manually using while loops and Regex parsing. This notebook demonstrates how LangChain simplifies this process into just a few lines of code.

Key Concepts

• LCEL (LangChain Expression Language): Declarative way to compose chains.
• LangChain Hub: Pulling pre-tested prompts (e.g., hwchase17/react).
• AgentExecutor: Automatic handling of the Thought-Action-Observation loop.