Practical Agentic RAG patterns implemented with LangGraph

Four self-contained Jupyter notebooks, each implementing a different way of making a Retrieval-Augmented Generation (RAG) pipeline "agentic" — able to decide, check itself, correct its own mistakes, or defer to a person, instead of blindly retrieving once and answering.

Each notebook is fully commented with markdown cells explaining what every step does and why — you don't need to already know LangGraph to follow along.

This is the free demo notebook (1_Agentic_RAG.ipynb). The full series — including Corrective RAG, Adaptive RAG, and Human-in-the-Loop RAG — is available here: Agentic RAG — Four Working Patterns with LangGraph

They sit on a spectrum of how much a RAG pipeline second-guesses itself — and who gets the final say:

• Agentic RAG — the retrieval decision itself is delegated to the LLM.
• Corrective RAG — retrieval always happens, but theresult is checked and corrected with a web-search fallback.
• Adaptive RAG — adds routing at the front (vectorstore vs. web)and a second self-check at the very end, on the generated answer itself.
• Human-in-the-Loop RAG — keeps the same grading/self-check machinery as Adaptive RAG, but the LLM's verdicts stop being routing decisions and become suggestions: a real person approves, revises, or rejects at two checkpoints using LangGraph'sinterrupt /Command(resume=...) pattern with aMemorySaver checkpointer.

Understanding all four, and where each one is worth the extra complexity, is more useful than knowing just one.

• VS Code with the Python and Jupyter extensions
• Python 3.11+
• uv — a fast, single-binary Python package/environment manager. It replacespip +venv with one tool and one lockfile.
• A Groq API key (free tier available) — used by all four notebooks as the LLM.
• A Tavily API key (free tier available) — used by the Corrective RAG and Adaptive RAG notebooks for live web search. Not needed for Agentic RAG or Human-in-the-Loop RAG.

Pick whichever matches your setup — you only need one of these.

macOS / Linux:

curl -LsSf https://astral.sh/uv/install.sh | sh

Windows (PowerShell):

powershell -c "irm https://astral.sh/uv/install.ps1 | iex"

Already have Python + pip and prefer not to run an install script:

pip install uv

Other options (Homebrew, pipx, winget, cargo, standalone downloads) are listed in the official install docs.

Check it worked:

uv --version

From the project folder:

uv sync

uv run python -m ipykernel install --user --name agentic-rag

Copy the env template and add your API keys:

macOS / Linux:

cp .env.example .env

Windows (Command Prompt):

copy .env.example .env

Windows (PowerShell):

Copy-Item .env.example .env

Open .env and fill in GROQ_API_KEY and TAVILY_API_KEY.

1. Install the Python andJupyter extensions in VS Code, if you don't already have them.
2. Open the project folder in VS Code (File > Open Folder... ).
3. Open any of the four .ipynb files.
4. In the top-right of the notebook, click Select Kernel and choose theagentic-rag kernel you registered above (it may show as.venv (Python 3.11) — pick the one whose path points at this project's.venv ).
5. Run the cells top to bottom with the ▶ buttons, or Run All .

That's the whole setup — no manually creating a virtualenv, no separate pip install -r requirements.txt step, and uv.lock means everyone who runs uv sync gets the exact same dependency versions you tested with.

Kernel is selected per notebook, not per project. VS Code remembers a separate kernel choice for each .ipynb file, so it's easy to open a second notebook and have it silently fall back to your global Python install instead of this project's .venv — especially if the .venv kernel hasn't been used in that notebook before. If one notebook runs fine but another throws import errors for packages this project clearly installs (e.g. chromadb, langchain_chroma), that's the first thing to check: open the kernel picker for the failing notebook and confirm the path points into this project's .venv, not AppData\Local\Programs\Python\... or any other system/global install.

1_Agentic_RAG.ipynb scrapes the LangGraph and LangChain documentation into two separate Chroma vector stores, wraps each as a retriever tool, and gives both tools to a tool-calling agent. The agent decides per question whether to call a tool, which one, and whether the retrieved documents are good enough to answer from or need a rewritten query.

2_Corrective_RAG.ipynb indexes a small set of blog posts on AI agents into one vector store. Every question always retrieves from it; a grading step then checks each retrieved chunk for relevance. If nothing relevant comes back, the question is rewritten for web search and Tavily fills the gap before the answer is generated.

3_Adaptive_RAG.ipynb builds on the same idea but adds a router at the very start (should this question go to the vectorstore or straight to the web?) and two more graders at the very end, checking that the generated answer is actually grounded in the retrieved documents and actually answers the question — looping back to retry if either check fails.

4_Human_in_the_Loop_RAG.ipynb takes the retrieve/grade/generate/self-check machinery from the Adaptive RAG notebook and puts a person in charge of the two decisions that used to be automatic:

• After retrieval, each document is graded for relevance as before, but the grade is shown to a human as a suggestion only — the human decides whether to proceed to generation or reject and have the question rewritten and re-retrieved.
• After generation, the two self-checks (grounded-in-documents, addresses-the-question) are shown for reference, but the human has the final call: approve, ask for a revision with their own feedback, or send it back to retrieval.

Mechanically, this runs on LangGraph's current recommended HITL pattern: interrupt(payload) called inside a node s the graph and surfaces payload to whoever is running it; resuming happens with graph.stream(Command(resume=...), config), and a MemorySaver checkpointer persists the graph's state while it's d. All branching still goes through plain add_conditional_edges rather than Command(goto=...), so every routing decision lives in one place. This notebook only needs GROQ_API_KEY — it doesn't call Tavily.

• Embeddings run locally via sentence-transformers (BAAI/bge-m3 ) — no embedding API key needed.
• Vector data is written to a local Chroma store at runtime and is not committed to the repo (chroma/ is gitignored).
• These notebooks scrape live documentation pages and blog posts at run time, so results will vary slightly as those pages change.

1_Agentic_RAG.ipynb is a free demo — use it, share it, redistribute it. The other three notebooks are a paid, personal-use resource — see LICENSE.md. In short: use them, learn from them, build on them, but don't resell or redistribute the notebooks themselves.

Get the full bundle here: Agentic RAG — Four Working Patterns with LangGraph