Free LangChain Course with Python
Learn LangChain step by step, from your first LLM app to agents and retrieval-augmented generation (RAG). Follow practical Python lessons with clear explanations and hands-on examples.
Start Learning →Learn LangChain with Python, step by step
This free LangChain tutorial is for learners who want to understand how to build applications with large language models. Start with what LangChain is, then practice prompts, LCEL, model workflows, and agents. The later lessons show how to load and retrieve information from documents to create a retrieval-augmented generation (RAG) app, including a simple RAG chatbot.
What you will learn
- Connect Python applications to LLM providers and local models.
- Compose prompts, models, and output parsers with LCEL.
- Build tool-using agents and conversational applications.
- Use embeddings and vector stores to build RAG workflows.
Who the course is for
Beginners can start with the introductory modules and work through the examples in order. Basic Python familiarity is helpful; you can explore the lessons for free and move at your own pace.
Course Modules
Introduction to Generative AI & LLMs
Generative AI basics, OpenAI and other providers, and what LangChain does in a real project.
4 lessonsSetup & Environment
OpenAI account, local models with Ollama, then project folder, venv, and LangChain dependencies.
3 lessonsLangChain Basics
First scripts with LangChain — OpenAI in the cloud, then Ollama on your PC with the same invoke pattern.
6 lessonsLCEL & Chains
Wire prompts, clients, and parsers with LCEL — then build sequential chains, parallel runnables, and streaming.
10 lessonsChat History & Memory
Multi-turn chats — slot past messages into templates, then persist and trim history with memory classes.
8 lessonsEmbeddings, Vector Stores & RAG
Load documents from files and the web, split them into chunks, embed them, store in a vector database, and build a RAG chatbot.
11 lessonsAgents
When the model picks its own steps — tool calling, ReAct, custom tools, and API hooks.
9 lessons