How to Create a Simple Chatbot Using OpenAI APIs and LangChain

Building an AI-powered chatbot has never been easier, thanks to OpenAI’s GPT models and LangChain. In this tutorial, we’ll walk through how to set up a simple chatbot using Python, OpenAI’s API, and the LangChain library.

What You’ll Need

• Python 3.8 or later
• OpenAI API key (Get it here)
• Install required libraries:

pip install openai langchain

Step 1: Set Up OpenAI and LangChain

First, configure the OpenAI API key in your environment:

export OPENAI_API_KEY="your_openai_api_key"

Or set it directly in Python (not recommended for production):

import os
os.environ["OPENAI_API_KEY"] = "your_openai_api_key"

Step 2: Create a Simple Chatbot

Here’s the Python code for a basic chatbot:

from langchain.chat_models import ChatOpenAI
from langchain.chains import ConversationChain
from langchain.memory import ConversationBufferMemory

# Initialize the OpenAI model
chat = ChatOpenAI(model_name="gpt-4o", temperature=0.7)

# Add memory to hold the conversation context
memory = ConversationBufferMemory()

# Create the conversation chain
conversation = ConversationChain(
    llm=chat,
    memory=memory,
    verbose=True
)

# Simple chat loop
print("🤖 Chatbot is ready! Type 'exit' to quit.")
while True:
    user_input = input("You: ")
    if user_input.lower() == "exit":
        print("Chatbot: Goodbye! 👋")
        break
    response = conversation.predict(input=user_input)
    print("Chatbot:", response)

Step 3: Run the Chatbot

Save the code to a file, e.g., chatbot.py, and run:

python chatbot.py

Now, you can chat with your AI assistant directly from the terminal!

What’s Next?

This is just the beginning! You can extend the chatbot by:
✅ Connecting it to a database or API
✅ Adding tools like web search or calculators using LangChain’s agents
✅ Deploying it as a web app using FastAPI or Streamlit