How To Build Agentic Applications with Streamlit and LangChain
Discover how to build powerful agentic applications by combining the simplicity of Streamlit with the advanced capabilities of LangChain. This method allows developers to create interactive, intelligent apps with minimal effort while leveraging cutting-edge language model tools.
Introduction
Creating AI-driven applications no longer requires complex setups. By merging Streamlit for rapid front-end deployment and LangChain for advanced language model orchestration, developers can quickly design agentic systems that interact with users and external tools in real time.
Core Setup
To start, install the required libraries:
pip install streamlit langchain openai
Streamlit manages the user interface, while LangChain integrates with LLMs and coordinates multiple components.
Key Components
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Agents in LangChain
LangChain provides different agent types, such as:-
Zero-Shot ReAct Agent β uses reasoning + actions for queries.
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Conversational Agent β maintains context across sessions.
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Custom Tools β integrate APIs, databases, or logic directly.
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Streamlit UI
With streamlit.chat_input and streamlit.chat_message, creating a chat-like experience is seamless. -
Memory Management
LangChain supports short-term and long-term memory, ensuring conversations remain contextual.
Implementation Example
import streamlit as st
from langchain.chat_models import ChatOpenAI
from langchain.agents import initialize_agent, load_tools
# Setup
llm = ChatOpenAI(temperature=0)
tools = load_tools(["serpapi", "llm-math"], llm=llm)
agent = initialize_agent(tools, llm, agent="zero-shot-react-description")
# UI
st.title("Agentic App with Streamlit + LangChain")
user_input = st.chat_input("Ask me anything")
if user_input:
with st.chat_message("user"):
st.markdown(user_input)
response = agent.run(user_input)
with st.chat_message("assistant"):
st.markdown(response)
This script combines Streamlitβs frontend simplicity with LangChainβs agent orchestration, producing a functional AI chatbot.
Advanced Enhancements
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Custom APIs: Connect with services like Google Search API, Wolfram Alpha, or internal databases.
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Chained Agents: Build multi-step workflows where one agent calls another.
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Deployment: Use
streamlit run app.py
to launch instantly.
Real-World Use Cases
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Customer Support Bots with contextual memory.
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Data Analysis Assistants that query structured datasets.
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Knowledge Base Explorers that connect to document search.
Conclusion
By integrating Streamlit + LangChain, developers gain a scalable, customizable framework for crafting agentic applications that feel natural, intelligent, and highly interactive.
For more details, check the official docs:
Enjoy!