LangChain and LangFlow are tools for developing applications using large language models (LLMs). LangChain provides libraries, templates, and tools to facilitate building context-aware systems using LLMs from prototype to production. It includes components, chains to process data, and LangSmith for debugging models. LangFlow is a GUI for LangChain. The presentation demonstrates LangChain's chat capabilities and use of tools/agents. It discusses building applications with LangChain and deploying them via LangServe APIs. LangChain aims to enhance LLM utility by making them more reasoning and context-aware.

1. LangChain and LangFlow
Gene Leybzon, Jim Steele
February 1, 2023

2. DISCLAIMER
§ The views and opinions expressed by the Presenter are those of the Presenter.
§ Presentation is not intended as legal or financial advice and may not be used as legal or
financial advice.
§ Every effort has been made to assure this information is up-to-date as of the date of
publication.

3. Agenda for today
1. LangChain Concept
2. Demo
3. LangFlow
4. Q&A

4. LangChain
Value Proposition:
LangChain is designed as a comprehensive toolkit for
developers working with large language models (LLMs).
It aims to facilitate the creation of applications that are
context-aware and capable of reasoning, thereby
enhancing the practical utility of LLMs in various
scenarios.
Purpose:
LangChain simplifies the transition from prototype to
production, offering a suite of tools for debugging, testing,
evaluation, and monitoring.

5. Parts of LangChain Framework
https://www.langchain.com/
•Libraries: Available in Python and JavaScript, these
libraries offer interfaces and integrations for various
components, a runtime for creating chains and agents,
and ready-made chain and agent implementations.
•Templates: This is a set of deployable reference
architectures for diverse tasks, facilitating ease of
deployment.
•LangServe: A specialized library for converting
LangChain chains into a REST API, enhancing
accessibility and integration.
•LangSmith: A comprehensive developer platform
designed for debugging, testing, evaluating, and
monitoring chains created with any LLM framework,
fully compatible with LangChain.

6. GenAI Application Development with LangChain
Develop
• Streamlined Prototyping:
Simplifies the process of
creating prototypes with large
language models.
• Context-Aware Systems:
Facilitates the building of
applications that understand
and utilize context effectively.
• Integration Support: Offers
tools for integrating various
data sources and components.
• Production Readiness: Provides
resources for debugging, testing,
evaluating, and monitoring
applications.
• Collaborative Development:
Encourages and supports
collaborative efforts in the
developer community.
• Diverse Applications: Suitable
for a wide range of
applications, from chatbots to
document analysis.
Turn into product
• Scalability: Provides tools to
scale applications from small
prototypes to larger,
production-level systems.
• Robust Testing: Offers robust
testing frameworks to ensure
application reliability.
• Monitoring Tools: Includes
monitoring capabilities to track
performance and user
interactions.
• Deployment Ease: Simplifies the
deployment process, making it
easier to launch applications.
• Continuous Improvement:
Supports ongoing development
and refinement of applications
post-launch.
Deploy
• LangServe: A library that allows
for the deployment of
LangChain chains as REST APIs,
making applications easily
accessible and integrable.
• Deployment Templates: Ready-
to-use reference architectures
that streamline the deployment
process for various tasks.
• Scalability Tools: Supports the
scaling of applications from
development to production level.
• Ease of Integration: Ensures
seamless integration with
existing systems and workflows.
• Production-Grade Support:
Offers features for ensuring
stability and performance in
production environments.

7. LangChain Components
LangChain components are designed
to enhance the development and
deployment of applications using large
language models. Components are
modular and easy-to-use, whether you
are using the rest of the LangChain
framework or not
https://python.langchain.com/docs/integrations
/components

8. LangChain Libraries
langchain-
core
• Base
abstractions
• LangChain
Expression
Language
langchain-
community
• Chat
Models
• Email Tools
• Database
integrations
langchain
• Chains
• Agents
• Data
Retrieval
Strategies

9. Base Abstractions
LangChain Base abstractions are
designed to simplify the process of
integrating and utilizing Large Language
Models (LLMs) in various applications.
These abstractions likely include
components for handling different
aspects of LLM integration, such as data
processing, model interaction, and
response generation. They are structured
to provide a foundation for building
complex LLM-based solutions,
streamlining development and allowing
for more efficient deployment. For a
detailed list and explanation of these
base abstractions, you would need to
refer to Langchain documentation or their
GitHub repository.
1.Languagemodels: This abstraction deals with the interaction with
language models. It includes the functionality to send prompts to a
language model and receive responses.
2.Chains: Chains are sequences of operations or transformations
applied to data. In Langchain, chains are used to process the input and
output of language models, allowing for complex workflows.
3.Apps: This abstraction is about building applications that use
language models. Apps combine different chains and models to create
an end-to-end application.
4.Actuators: Actuators are about taking action based on the output of
a language model. This could include sending an email, generating a
report, or any other action that results from the language model's
output.
5.World Models: These are abstractions for representing and
understanding the state of the world. They can be used to maintain
context or state across interactions with a language model.
6.Orchestrators: Orchestrators manage and coordinate the
interactions between different components of the system, such as the
language model, chains, actuators, and world models.
7.Components: These are smaller building blocks used within
chains. Components can be anything from a simple text processing
function to a complex neural network.
8.Data Sources: Abstractions for managing and accessing data that
the language model or other components might need. This could
include databases, APIs, or file systems.

10. LANGCHAIN DEMO

11. INSTALLATION AND CONFIGURATION
pip install langchain
pip install langchain-openai OPENAI_API_KEY
sudo vi /etc/launchd.conf
export OPENAI_API_KEY = “K
Install LangChain and OpenAI Model: Set up API KEY for OpenAI:

12. HELLO OPENAI LANGCHAIN
from langchain_openai import ChatOpenAI
llm = ChatOpenAI()
r = llm.invoke("how can langsmith help with testing?")
print(r)

13. PROMPT TEMPLATE
from langchain_openai import ChatOpenAI
from langchain_core.prompts import ChatPromptTemplate
from langchain_core.output_parsers import StrOutputParser
llm = ChatOpenAI()
prompt = ChatPromptTemplate.from_messages([
("system", "You are world class technical documentation writer."),
("user", "{input}")
])
chain = prompt | llm
r = chain.invoke({"input": "how can langsmith help with testing?"})
print(r)

14. OUTPUT PARSER
from langchain_openai import ChatOpenAI
from langchain_core.prompts import ChatPromptTemplate
from langchain_core.output_parsers import StrOutputParser
llm = ChatOpenAI()
prompt = ChatPromptTemplate.from_messages([
("system", "You are world class technical documentation writer."),
("user", "{input}")
])
output_parser = StrOutputParser()
chain = prompt | llm | output_parser
r = chain.invoke({"input": "how can langsmith help with testing?"})
print(r)

15. “RANDOM” AGENT
import sys
import random
from langchain_openai import ChatOpenAI
from langchain.agents import tool
from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
from langchain_community.tools.convert_to_openai import format_tool_to_openai_function
from langchain.agents.format_scratchpad import format_to_openai_function_messages
from langchain.agents.output_parsers import OpenAIFunctionsAgentOutputParser
from langchain.agents import AgentExecutor
@tool
def get_word_length(word: str) -> int:
"""Returns the length of a word."""
return len(word)
@tool
def random_number() -> int:
"""Returns random number"""
return random.randint(0, sys.maxsize)
tools = [get_word_length, random_number]
llm = ChatOpenAI(model="gpt-3.5-turbo", temperature=0)
prompt = ChatPromptTemplate.from_messages(
[
(
"system",
"You are very powerful assistant, but don't know current events",
),
("user", "{input}"),
MessagesPlaceholder(variable_name="agent_scratchpad"),
]
)
llm_with_tools = llm.bind(functions=[format_tool_to_openai_function(t) for t in tools])
agent = (
{
"input": lambda x: x["input"],
"agent_scratchpad": lambda x: format_to_openai_function_messages(
x["intermediate_steps"]
),
}
| prompt
| llm_with_tools
| OpenAIFunctionsAgentOutputParser()
)
agent_executor = AgentExecutor(agent=agent, tools=tools, verbose=True)
agent_executor.invoke({"input": "How many letters in the word educator"})
agent_executor.invoke({"input": "Generate 10 random numbers"})

16. THE ROLE OF ART AND POETRY
# Import necessary modules and classes
import os
import json
import datetime
from langchain.agents import load_tools, initialize_agent, AgentType, ZeroShotAgent, Tool, AgentExecutor
from langchain_community.utilities import SerpAPIWrapper
from typing import List, Dict, Callable
from langchain.chains import ConversationChain
from langchain_openai import OpenAI, ChatOpenAI
from langchain.memory import ConversationBufferMemory
from langchain.prompts.prompt import PromptTemplate
from langchain.schema import AIMessage, HumanMessage, SystemMessage, BaseMessage
from jinja2 import Environment, FileSystemLoader
# Set environment variables for API keys and configurations
#os.environ['OPENAI_API_KEY'] = str("")
#os.environ["SERPAPI_API_KEY"] = str("")
os.environ["LANGCHAIN_TRACING_V2"]="false"
os.environ["LANGCHAIN_ENDPOINT"]="https://api.smith.langchain.com"
#os.environ["LANGCHAIN_API_KEY"]="" #https://smith.langchain.com/
os.environ["LANGCHAIN_PROJECT"]="pt-wooden-infix-62"
#Constants
#topic = "Ethics and the Good Life"
topic = "The Role of Art and Poetry"
word_limit = 300
names = {
"Plato": ["arxiv", "ddg-search", "wikipedia"],
"Aristotle": ["arxiv", "ddg-search", "wikipedia"],
}
max_dialogue_rounds = 8
#Language Model Initialization
llm = OpenAI(temperature=0, model_name='gpt-4-1106-preview’)
...
Plato Aristotle
Your name is {name}.
Your description is as follows: {description}
Your goal is to persuade your conversation partner of your point of view.
DO look up information with your tool to refute your partner's claims.
DO cite your sources.
DO NOT fabricate fake citations.
DO NOT cite any source that you did not look up.
Do not add anything else.
Stop speaking the moment you finish speaking from your perspective.

17. LANGFLOW

18. LANGFLOW – GUI FOR LANGCHAIN

19. QUESTIONS?

20. About Presenter
https://www.meetup.com/members/9074420/
https://www.linkedin.com/in/leybzon/