LangGraph

Integrate LangGraph's graph-based orchestration with Agent Kernel.

Installation

pip install agentkernel[langgraph]

Basic Usage

from typing import TypedDict
from langgraph.graph import StateGraph, END
from agentkernel.cli import CLI
from agentkernel.langgraph import LangGraphModule

class State(TypedDict):
    messages: list

def agent_node(state: State):
    # Your logic
    return {"messages": state["messages"] + ["response"]}

# Build graph
workflow = StateGraph(State)
workflow.add_node("agent", agent_node)
workflow.set_entry_point("agent")
workflow.add_edge("agent", END)

# Compile
graph = workflow.compile()
graph.name = "assistant"

LangGraphModule([graph])

if __name__ == "__main__":
    CLI.main()

Complex Graph

from langgraph.graph import StateGraph, END

# Multi-node graph with conditional routing
workflow = StateGraph(State)
workflow.add_node("analyzer", analyze_node)
workflow.add_node("responder", respond_node)
workflow.add_node("validator", validate_node)

workflow.set_entry_point("analyzer")
workflow.add_conditional_edges(
    "analyzer",
    router_func,
    {
        "respond": "responder",
        "validate": "validator"
    }
)
workflow.add_edge("responder", END)
workflow.add_edge("validator", "responder")

graph = workflow.compile()
graph.name = "complex_agent"

Configuration

export OPENAI_API_KEY=sk-...

Tool Binding

Use LangGraphToolBuilder to bind plain Python functions as tools to your LangGraph agents:

from langgraph.prebuilt import create_react_agent
from agentkernel.langgraph import LangGraphModule, LangGraphToolBuilder

def get_weather(city: str) -> str:
    """Returns the weather for a given city."""
    return f"Weather in {city}: sunny, 25°C"

weather_agent = create_react_agent(
    name="weather",
    tools=LangGraphToolBuilder.bind([get_weather]),
    model=model,
    prompt="Use the get_weather tool for weather-related questions.",
)

LangGraphModule([weather_agent])

Both sync and async functions are supported. Async functions are automatically passed as coroutines.

See Tools for the full guide on writing and binding tools.

Features

• ✅ Graph-based workflows
• ✅ Conditional routing
• ✅ State management
• ✅ Checkpointing
• ✅ Framework-agnostic tool binding

Example

See examples/cli/langgraph for complete examples.