Build RAG Chatbot with LangChain, Zilliz Cloud, Anthropic Claude 3.5 Sonnet, and Cohere embed-english-light-v2.0

Introduction to RAG

Retrieval-Augmented Generation (RAG) is a game-changer for GenAI applications, especially in conversational AI. It combines the power of pre-trained large language models (LLMs) like OpenAI’s GPT with external knowledge sources stored in vector databases such as Milvus and Zilliz Cloud, allowing for more accurate, contextually relevant, and up-to-date response generation. A RAG pipeline usually consists of four basic components: a vector database, an embedding model, an LLM, and a framework.

Key Components We'll Use for This RAG Chatbot

This tutorial shows you how to build a simple RAG chatbot in Python using the following components:

LangChain: An open-source framework that helps you orchestrate the interaction between LLMs, vector stores, embedding models, etc, making it easier to integrate a RAG pipeline.
Zilliz Cloud: a fully managed vector database-as-a-service platform built on top of the open-source Milvus, designed to handle high-performance vector data processing at scale. It enables organizations to efficiently store, search, and analyze large volumes of unstructured data, such as text, images, or audio, by leveraging advanced vector search technology. It offers a free tier supporting up to 1 million vectors.
Anthropic Claude 3.5 Sonnet: This advanced model in the Claude 3 family is designed for nuanced understanding and creative language generation. With enhanced prompt comprehension and contextual awareness, it excels in complex dialogue, creative writing, and sophisticated content creation. Ideal for applications where deep engagement and high-quality output are paramount.
Cohere embed-english-light-v2.0: This lightweight embedding model is designed for efficient English text encoding, providing high-quality representations for various natural language processing tasks. It excels in scenarios requiring embedding generation with minimal computational resources, such as document similarity, clustering, and recommendation systems, ensuring fast performance without compromising accuracy.

By the end of this tutorial, you’ll have a functional chatbot capable of answering questions based on a custom knowledge base.

Note: Since we may use proprietary models in our tutorials, make sure you have the required API key beforehand.

Step 1: Install and Set Up LangChain

%pip install --quiet --upgrade langchain-text-splitters langchain-community langgraph

Step 2: Install and Set Up Anthropic Claude 3.5 Sonnet

pip install -qU "langchain[anthropic]"

import getpass
import os

if not os.environ.get("ANTHROPIC_API_KEY"):
  os.environ["ANTHROPIC_API_KEY"] = getpass.getpass("Enter API key for Anthropic: ")

from langchain.chat_models import init_chat_model

llm = init_chat_model("claude-3-5-sonnet-latest", model_provider="anthropic")

Step 3: Install and Set Up Cohere embed-english-light-v2.0

pip install -qU langchain-cohere

import getpass
import os

if not os.environ.get("COHERE_API_KEY"):
  os.environ["COHERE_API_KEY"] = getpass.getpass("Enter API key for Cohere: ")

from langchain_cohere import CohereEmbeddings

embeddings = CohereEmbeddings(model="embed-english-light-v2.0")

Step 4: Install and Set Up Zilliz Cloud

pip install -qU langchain-milvus

from langchain_milvus import Zilliz

vector_store = Zilliz(
    embedding_function=embeddings,
    connection_args={
        "uri": ZILLIZ_CLOUD_URI,
        "token": ZILLIZ_CLOUD_TOKEN,
    },
)

Step 5: Build a RAG Chatbot

Now that you’ve set up all components, let’s start to build a simple chatbot. We’ll use the Milvus introduction doc as a private knowledge base. You can replace it with your own dataset to customize your RAG chatbot.

import bs4
from langchain import hub
from langchain_community.document_loaders import WebBaseLoader
from langchain_core.documents import Document
from langchain_text_splitters import RecursiveCharacterTextSplitter
from langgraph.graph import START, StateGraph
from typing_extensions import List, TypedDict

# Load and chunk contents of the blog
loader = WebBaseLoader(
    web_paths=("https://milvus.io/docs/overview.md",),
    bs_kwargs=dict(
        parse_only=bs4.SoupStrainer(
            class_=("doc-style doc-post-content")
        )
    ),
)

docs = loader.load()

text_splitter = RecursiveCharacterTextSplitter(chunk_size=1000, chunk_overlap=200)
all_splits = text_splitter.split_documents(docs)

# Index chunks
_ = vector_store.add_documents(documents=all_splits)

# Define prompt for question-answering
prompt = hub.pull("rlm/rag-prompt")


# Define state for application
class State(TypedDict):
    question: str
    context: List[Document]
    answer: str


# Define application steps
def retrieve(state: State):
    retrieved_docs = vector_store.similarity_search(state["question"])
    return {"context": retrieved_docs}


def generate(state: State):
    docs_content = "\n\n".join(doc.page_content for doc in state["context"])
    messages = prompt.invoke({"question": state["question"], "context": docs_content})
    response = llm.invoke(messages)
    return {"answer": response.content}


# Compile application and test
graph_builder = StateGraph(State).add_sequence([retrieve, generate])
graph_builder.add_edge(START, "retrieve")
graph = graph_builder.compile()

Test the Chatbot

Yeah! You've built your own chatbot. Let's ask the chatbot a question.

response = graph.invoke({"question": "What data types does Milvus support?"})
print(response["answer"])

Example Output

Milvus supports various data types including sparse vectors, binary vectors, JSON, and arrays. Additionally, it handles common numerical and character types, making it versatile for different data modeling needs. This allows users to manage unstructured or multi-modal data efficiently.

Optimization Tips

As you build your RAG system, optimization is key to ensuring peak performance and efficiency. While setting up the components is an essential first step, fine-tuning each one will help you create a solution that works even better and scales seamlessly. In this section, we’ll share some practical tips for optimizing all these components, giving you the edge to build smarter, faster, and more responsive RAG applications.

LangChain optimization tips

To optimize LangChain, focus on minimizing redundant operations in your workflow by structuring your chains and agents efficiently. Use caching to avoid repeated computations, speeding up your system, and experiment with modular design to ensure that components like models or databases can be easily swapped out. This will provide both flexibility and efficiency, allowing you to quickly scale your system without unnecessary delays or complications.

Zilliz Cloud optimization tips

Optimizing Zilliz Cloud for a RAG system involves efficient index selection, query tuning, and resource management. Use Hierarchical Navigable Small World (HNSW) indexing for high-speed, approximate nearest neighbor search while balancing recall and efficiency. Fine-tune ef_construction and M parameters based on your dataset size and query workload to optimize search accuracy and latency. Enable dynamic scaling to handle fluctuating workloads efficiently, ensuring smooth performance under varying query loads. Implement data partitioning to improve retrieval speed by grouping related data, reducing unnecessary comparisons. Regularly update and optimize embeddings to keep results relevant, particularly when dealing with evolving datasets. Use hybrid search techniques, such as combining vector and keyword search, to improve response quality. Monitor system metrics in Zilliz Cloud’s dashboard and adjust configurations accordingly to maintain low-latency, high-throughput performance.

Anthropic Claude 3.5 Sonnet optimization tips

Claude 3.5 Sonnet delivers enhanced reasoning while maintaining a balance between speed and complexity. Optimize by refining retrieval pipelines to prioritize top-ranked context, reducing unnecessary token consumption. Use adaptive chunking methods to provide structured and concise context, ensuring that the model receives only the most relevant information. Implement a dynamic query selection approach, routing simpler questions to Claude 3.5 Haiku for cost and speed efficiency while reserving Sonnet for deeper reasoning. Optimize API request handling with batch processing and response caching to lower latency. Fine-tune temperature and sampling settings, keeping them low for deterministic outputs in retrieval-based tasks. Use system instructions to guide responses, improving consistency and reducing hallucinations. If deploying at scale, leverage parallel query execution and real-time monitoring to dynamically adjust workloads based on system performance metrics.

Cohere embed-english-light-v2.0 optimization tips

Cohere embed-english-light-v2.0 is designed for faster, more resource-efficient embedding generation in English-language tasks. To optimize processing, preprocess text by removing stopwords, punctuation, and unnecessary formatting to minimize the complexity of the input. Leverage vector compression techniques, such as quantization or PCA, to reduce storage requirements without sacrificing significant accuracy. For retrieval, implement hybrid search strategies that combine keyword search with dense vector search to achieve faster and more relevant results. Use multi-threading or parallel processing to handle large batches of embeddings efficiently. Apply caching for frequently queried embeddings to minimize re-processing and reduce query latency, especially for high-traffic RAG systems.

By implementing these tips across your components, you'll be able to enhance the performance and functionality of your RAG system, ensuring it’s optimized for both speed and accuracy. Keep testing, iterating, and refining your setup to stay ahead in the ever-evolving world of AI development.

RAG Cost Calculator: A Free Tool to Calculate Your Cost in Seconds

Estimating the cost of a Retrieval-Augmented Generation (RAG) pipeline involves analyzing expenses across vector storage, compute resources, and API usage. Key cost drivers include vector database queries, embedding generation, and LLM inference.

RAG Cost Calculator is a free tool that quickly estimates the cost of building a RAG pipeline, including chunking, embedding, vector storage/search, and LLM generation. It also helps you identify cost-saving opportunities and achieve up to 10x cost reduction on vector databases with the serverless option.

Calculate your RAG cost now.

Calculate your RAG cost

What Have You Learned?

What an incredible journey you've embarked on! In this tutorial, you’ve learned how to weave together a powerful RAG system by integrating a framework, a vector database, a large language model, and an embedding model. Together, these components create a robust architecture that can handle information retrieval and conversational tasks with remarkable efficiency.

You’ve discovered how the framework—like LangChain—serves as the backbone, orchestrating the collaboration of the different parts to create a seamless user experience. The vector database, powered by Zilliz Cloud, ensures that your searches are lightning-fast, significantly enhancing retrieval times and making your applications more responsive than ever. Meanwhile, with the innovative Anthropic Claude 3.5 Sonnet, your system gains conversational intelligence, allowing it to engage users in a natural, human-like manner. And with the Cohere embed-english-light-v2.0 embedding model, you’re equipping your RAG application with rich semantic representations that capture nuances in language, making interactions even more meaningful.

Don't forget the extra features we discussed, like optimization tips and the free cost calculator—tools that will guide your efforts as you take your understanding to the next level. Now it’s your turn to dive in! Start building, optimizing, and innovating your very own RAG applications. The possibilities are boundless, and I can’t wait to see the incredible solutions you'll create. Your journey has just begun—let your creativity flow and make technology work for you!

Further Resources

🌟 In addition to this RAG tutorial, unleash your full potential with these incredible resources to level up your RAG skills.

How to Build a Multimodal RAG | Documentation
How to Enhance the Performance of Your RAG Pipeline
Graph RAG with Milvus | Documentation
How to Evaluate RAG Applications - Zilliz Learn
Generative AI Resource Hub | Zilliz

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