LlamaIndex Retrievers Integration: MongoDBAtlasBM25Retriever

What is this?

This is a BM25 Retriever for MongoDB Atlas that can be used with LlamaIndex.

How to use

This was created with reference to MongoDBAtlasVectorSearch, so it's mostly the same.

Please refer to that.

However, while MongoDBAtlasVectorSearch is an VectorStore, MongoDBAtlasBM25Retriever is a Retriever.

MongoDBAtlasBM25Retriever Example:

mongodb_client = pymongo.MongoClient(mongo_uri)

retriever = MongoDBAtlasBM25Retriever(
    mongodb_client=mongodb_client,
    db_name="vectorstore",
    collection_name="vector_collection",
    index_name="index_vector_collection",
)
nodes = retriever.retrieve("retrieve_query")