Generating chatbot responses

Designing Agentic Systems with LangChain

Dilini K. Sumanapala, PhD

Founder & AI Engineer, Genverv, Ltd.

Streaming graph events

   

  • Stream events in real-time

  • Each event is a workflow step

  • Track responses and tool calls

  • Track chatbot progress

User: Where is the Congo?

Agent: Let me check some details 
       for you...

Agent: AIMessage([Tool Call to 
       Google Maps] Searching for 
       information on "the Congo")

Agent: The Democratic Republic of 
       Congo is a country in 
       Central Africa.
Designing Agentic Systems with LangChain

Streaming LLM responses

# Define a function to execute the chatbot based on user input
def stream_graph_updates(user_input: str):


    # Start streaming events from the graph with the user's input
    for event in graph.stream({"messages": [("user", user_input)]}):


        # Retrieve and print the chatbot node responses
        for value in event.values():
            print("Agent:", value["messages"])


# Define the user query and run the chatbot
user_query = "Who is Mary Shelley?"
stream_graph_updates(user_query)
Designing Agentic Systems with LangChain

Streaming LLM responses

   Agent: [AIMessage(content='Mary Shelley (1797-1851) was an English 
   novelist...

   ...best known for her groundbreaking work in the Gothic genre, 
   particularly for her novel "Frankenstein; or, The Modern Prometheus," 
   published in 1818. This novel is often considered one of the earliest 
   examples of science fiction and explores themes of creation, 
   responsibility, and the nature of humanity through the story of Victor 
   Frankenstein, a scientist who creates a sentient creature in an 
   unorthodox experiment...',

   response_metadata={'finish_reason': 'stop', 'model_name': 
   'gpt-4o-mini-...')]
Designing Agentic Systems with LangChain

LLMs and hallucinations

Agent: [AIMessage(content='Judith 
Love Cohen was an American aerospace 
engineer, and worked on various 
space missions, including the Apollo 
program... Cohen was also the mother 
of actor and writer Adam Cohen, 
who has spoken about her influence on 
his life and career. 
additional_kwargs={}, 
response_metadata={'finish_reason': 
'stop', 'model_name': 
'gpt-4o-mini-...)

   

Example hallucination

 

  • Judith Love Cohen's famous son is Jack Black, not "Adam Cohen".
Designing Agentic Systems with LangChain

Generate a LangGraph diagram

# Import modules for chatbot diagram
from IPython.display import 
Image, display


# Try generating and displaying 
# the graph diagram
try:
    display(Image(graph.get_graph()
    .draw_mermaid_png()))


# Return an exception if necessary  
except Exception:
    print("Additional dependencies 
    required.")

Basic chatbot LangGraph diagram.

Designing Agentic Systems with LangChain

Let's practice!

Designing Agentic Systems with LangChain

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