Multi-agent graphs in LangChain - Mini Project: Build & Apply

Multi-agent Graphs with Langchain

📖 Scenario: You are building a simple multi-agent system using Langchain where agents communicate through a graph structure. Each agent has a name and a role, and the graph shows connections between agents.

🎯 Goal: Create a multi-agent graph using Langchain's graph data structures. You will define agents, set up a configuration for connection rules, build the graph with edges between agents, and finalize the graph for use.

📋 What You'll Learn

Create a dictionary called agents with exact agent names and roles

Define a variable min_connections to set the minimum number of connections per agent

Use a loop to add edges between agents in a MultiAgentGraph object

Complete the graph setup by calling finalize() on the graph object

💡 Why This Matters

🌍 Real World

Multi-agent graphs help model communication and collaboration in teams, robotics, or AI systems.

💼 Career

Understanding multi-agent systems and graph structures is useful for AI developers, data scientists, and system architects.

1

Define the agents dictionary

Create a dictionary called agents with these exact entries: 'Alice': 'manager', 'Bob': 'developer', 'Carol': 'designer', 'Dave': 'tester'.

LangChain

# Create the agents dictionary with names and roles
# Your code here

Need a hint?

Use curly braces to create a dictionary with keys as agent names and values as their roles.

2

Set minimum connections configuration

Define a variable called min_connections and set it to 2 to specify the minimum number of connections each agent should have.

LangChain

agents = {
    'Alice': 'manager',
    'Bob': 'developer',
    'Carol': 'designer',
    'Dave': 'tester'
}
# Define min_connections variable
# Your code here

Need a hint?

Just assign the number 2 to the variable min_connections.

3

Build the multi-agent graph with edges

Create a MultiAgentGraph object called graph. Use a for loop with variables agent1 and role1 to iterate over agents.items(). Inside it, use another for loop with variables agent2 and role2 to iterate over agents.items(). Add an edge between agent1 and agent2 in graph only if agent1 != agent2. Use the method graph.add_edge(agent1, agent2).

LangChain

agents = {
    'Alice': 'manager',
    'Bob': 'developer',
    'Carol': 'designer',
    'Dave': 'tester'
}
min_connections = 2

# Create MultiAgentGraph and add edges between different agents
# Your code here

Need a hint?

Use nested loops to connect each agent to every other agent except itself.

4

Finalize the multi-agent graph

Add a method finalize() to the MultiAgentGraph class that sets an attribute is_finalized to true. Then call graph.finalize() to complete the graph setup.

LangChain

agents = {
    'Alice': 'manager',
    'Bob': 'developer',
    'Carol': 'designer',
    'Dave': 'tester'
}
min_connections = 2

class MultiAgentGraph:
    def __init__(self):
        self.edges = []
    def add_edge(self, a1, a2):
        self.edges.append((a1, a2))
    # Add finalize method here

graph = MultiAgentGraph()
for agent1, role1 in agents.items():
    for agent2, role2 in agents.items():
        if agent1 != agent2:
            graph.add_edge(agent1, agent2)

# Call finalize on graph
# Your code here

Need a hint?

Define the finalize method inside the class and call it on the graph object.