Agent & RAG Frameworks

LangChain, LlamaIndex, Haystack, MCP & AgentOps

RAG & Agent Frameworks

🔗 LangChain

Meaning: A framework for building LLM-powered apps with memory, tool use, and RAG.
Example: Building a customer-support chatbot that looks up your company's knowledge base before answering.
from langchain.chat_models import ChatOpenAI
from langchain.chains import RetrievalQA

# Initialize LLM and retrieval chain
llm = ChatOpenAI()
qa_chain = RetrievalQA.from_chain_type(llm=llm)

# Query with context
response = qa_chain.run("What is our refund policy?")
print(response)

📊 LlamaIndex

Meaning: Specializes in connecting LLMs to your structured/unstructured data.
Example: A law firm loads thousands of PDFs (contracts) → chatbot answers legal queries from those docs.

Key Features:

  • Advanced document indexing
  • Query routing and optimization
  • Structured data integration
  • Multi-modal support (text, tables, images)

🌾 Haystack

Meaning: An open-source RAG framework for production-ready search + QA.
Example: News company builds a search system where users can ask "Summarize all articles about inflation in 2025" → Haystack + LLM answers.

Production Features:

  • Pipeline-based architecture
  • Built-in evaluation tools
  • Scalable document stores
  • REST API ready

Infrastructure & Operations

🔌 MCP (Model Context Protocol)

Meaning: A standard by Anthropic for LLMs to talk to tools, data, and each other.
Example: Instead of writing custom APIs for every agent, MCP defines a "language" → easier to plug models into company systems.

Benefits:

  • Standardized tool interfaces
  • Interoperability between different LLMs
  • Simplified integration with enterprise systems
  • Built-in security and access controls

🎯 AgentOps

Meaning: A framework to observe, debug, and track AI agents (like DevOps but for AI agents).
Example: Team deploys multiple AI assistants (data cleaner, recruiter bot) → AgentOps monitors errors, costs, and tool usage.

Key Capabilities:

  • Agent performance monitoring
  • Cost tracking per agent/task
  • Error detection and alerting
  • Tool usage analytics
  • A/B testing for prompts

Understanding Agents vs LLMs

🧠 LLM (Large Language Model)

Meaning: A model trained to generate text (predicts the next word).
Example: Ask "What's 2+2?" → it answers "4."

Characteristics:

  • Stateless (no memory between calls)
  • Text in, text out
  • No external actions
  • Single-turn interactions

🤖 Agent

Meaning: An LLM wrapped with memory, tools, and goals → can reason and act.
Example: Agent gets task: "Book me a flight and add it to my calendar."
It:
  • Talks to flight API
  • Confirms booking
  • Adds event to Google Calendar

Design Patterns:

  • ReAct: Reason + Act loop
  • Planner-Executor: One agent plans, another executes
  • Multi-agent teams: Recruiter bot + reviewer bot + scheduler bot work together