Who it's for
For developers who write Python and have called an API before. You need Python 3 and API keys for an embedding model, Claude and a judge model, plus a Postgres server with pgvector for lessons 2 and 3.
Lessons
- 1RAG tutorial: build a retrieval pipeline step by stepA RAG tutorial for developers: split documents, embed them with Voyage AI, retrieve by similarity and have Claude answer with citations.
- 2What are embeddings? Models, dimensions and pgvector for developersWhat are embeddings and how do you use them? Pick a model and a dimension, compare vectors with cosine similarity and store them in Postgres.
- 3RAG chunking strategies: chunk size, overlap, contextual retrieval and hybrid searchRAG chunking strategies for developers: choose a chunk size and overlap, split by structure, add context to each chunk and combine BM25 with vectors.
- 4How to evaluate RAG: retrieval metrics, faithfulness and a small test setHow to evaluate RAG: build a small test set, measure retrieval with context recall and precision, and score answers for faithfulness with Ragas.
Frequently asked questions
Is this RAG course free?
Yes. Every lesson is free to read. To follow along you need API keys for an embedding model, Claude and a judge model, and those providers may bill for their use.
Do I need LangChain or LlamaIndex?
No. Lesson 1 retrieves with a few lines of NumPy and calls the model directly. It borrows LangChain's text splitter for chunking, and lessons 3 and 4 use LangChain's splitters and Ragas.
Which vector database does the course use?
Postgres with the pgvector extension. Lesson 2 covers its distance operators, its HNSW and IVFFlat indexes, its dimension limits and filtered queries, and lesson 1 starts with vectors held in memory.
Which versions of the tools do the lessons follow?
The documentation as it stood on 5 November 2026, including pgvector 0.8.7, the Voyage 4 model series and Ragas 0.4.3, the newest release on PyPI. The Ragas pages it relies on are dated 9 December 2025, so pin the version you install.
What should I learn after this course?
The advanced prompt engineering course is next, the first course of the Master prompting path. Its first lesson teaches a model with examples, and the path goes on to reasoning models and prompt optimization.
