> ## Documentation Index
> Fetch the complete documentation index at: https://docs.galileo.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# MongoDB Atlas Integration for Retrieval-Augmented Generation (RAG)

> Guide to using MongoDB Atlas Vector Search with LangGraph agents logging to Galileo

## MongoDB + RAG + Galileo overview

MongoDB Atlas Vector Search lets you keep your knowledge base *inside* MongoDB while enjoying hybrid search and AI-ready workloads.
In this guide you'll:

1. Embed and store vectors in Atlas
2. Setup Galileo
3. Stream LangGraph traces to **Galileo** for end-to-end observability

## Set up MongoDB

Sign up to MongoDB Atlas and set up your credentials. You can setup the vector store as follows:

```python theme={null}
from langchain_mongodb import MongoDBAtlasVectorSearch
from langchain_openai import OpenAIEmbeddings
from pymongo import MongoClient

client          = MongoClient(MONGODB_URI)
DB_NAME         = "rag_demo"
COLLECTION_NAME = "blog_vectors"

collection = client[DB_NAME][COLLECTION_NAME]
embeddings = OpenAIEmbeddings()

vector_store = MongoDBAtlasVectorSearch(
    collection    = collection,
    embedding     = embeddings,
    index_name    = "rag-index",
    relevance_score_fn = "cosine"
)
```

## Use Galileo for logging

```python theme={null}
import os
from galileo.handlers.langchain import GalileoCallback

# --- Galileo ---
os.environ["GALILEO_API_KEY"] = "<galileo-key>"
os.environ["GALILEO_PROJECT"] = "<galileo-project>"
os.environ["GALILEO_LOG_STREAM"] = "mongo_rag_demo"

# You can leave this commented out if you are using app.galileo.ai
# os.environ["GALILEO_CONSOLE_URL"] = "<galileo-console-url>"

galileo_handler = GalileoCallback()
```

Once the callback is created we can add it to the agent.

```python theme={null}
query = "What types of agent memory does Lilian Weng describe?"
inputs = {"messages": [HumanMessage(content=query)]}

result = graph.invoke(
    inputs,
    config={"recursion_limit": 5, "callbacks": [galileo_handler]}
)
```

Find the full notebook [in Google Colab](https://colab.research.google.com/github/rungalileo/examples/blob/main/examples/RAG/logstreams/Galileo_LangGraph_Agent_with_MongoDB_Atlas_Vector_Search_for_RAG.ipynb).