.ipynb
.pdf
Chat Over Documents with Vectara
 Contents 
Pass in chat history
Return Source Documents
ConversationalRetrievalChain with search_distance
ConversationalRetrievalChain with map_reduce
ConversationalRetrievalChain with Question Answering with sources
ConversationalRetrievalChain with streaming to stdout
get_chat_history Function
Chat Over Documents with Vectara#
This notebook is based on the chat_vector_db notebook, but using Vectara as the vector database.
import os
from langchain.vectorstores import Vectara
from langchain.vectorstores.vectara import VectaraRetriever
from langchain.llms import OpenAI
from langchain.chains import ConversationalRetrievalChain
Load in documents. You can replace this with a loader for whatever type of data you want
from langchain.document_loaders import TextLoader
loader = TextLoader("../../modules/state_of_the_union.txt")
documents = loader.load()
We now split the documents, create embeddings for them, and put them in a vectorstore. This allows us to do semantic search over them.
vectorstore = Vectara.from_documents(documents, embedding=None)
We can now create a memory object, which is neccessary to track the inputs/outputs and hold a conversation.
from langchain.memory import ConversationBufferMemory
memory = ConversationBufferMemory(memory_key="chat_history", return_messages=True)
We now initialize the ConversationalRetrievalChain
openai_api_key = os.environ['OPENAI_API_KEY']
llm = OpenAI(openai_api_key=openai_api_key, temperature=0)
retriever = vectorstore.as_retriever(lambda_val=0.025, k=5, filter=None)
d = retriever.get_relevant_documents('What did the president say about Ketanji Brown Jackson')
rtdocs_stable/api.python.langchain.com/en/stable/integrations/vectara/vectara_chat.html