kagent-langgraph 0.9.2

LangGraph integration for KAgent with A2A server support

KAgent LangGraph Integration

This package provides LangGraph integration for KAgent with A2A (Agent-to-Agent) server support. It implements a custom checkpointer that persists LangGraph state to the KAgent REST API, enabling distributed agent execution with session persistence.

Features

• Custom Checkpointer: Persists LangGraph checkpoints to KAgent via REST API
• A2A Server Integration: Compatible with KAgent's Agent-to-Agent protocol
• Session Management: Automatic session creation and state persistence
• Event Streaming: Real-time streaming of graph execution events
• FastAPI Integration: Ready-to-deploy web server for agent execution

Quick Start

from kagent_langgraph import KAgentApp
from langgraph.graph import StateGraph
from langchain_core.messages import BaseMessage
from typing import TypedDict, Annotated, Sequence

class State(TypedDict):
    messages: Annotated[Sequence[BaseMessage], "The conversation history"]

# Define your graph
builder = StateGraph(State)
# Add nodes and edges...

# Create KAgent app
app = KAgentApp(
    graph_builder=builder,
    agent_card={
        "name": "my-langgraph-agent",
        "description": "A LangGraph agent with KAgent integration",
        "version": "0.1.0",
        "capabilities": {"streaming": True},
        "defaultInputModes": ["text"],
        "defaultOutputModes": ["text"]
    },
    kagent_url="http://localhost:8083",
    app_name="my-agent"
)

# Build FastAPI application
fastapi_app = app.build()

Architecture

The package mirrors the structure of kagent-adk but uses LangGraph instead of Google's ADK:

• KAgentCheckpointer: Custom checkpointer that stores graph state in KAgent sessions
• LangGraphAgentExecutor: Executes LangGraph workflows within A2A protocol
• KAgentApp: FastAPI application builder with A2A integration
• Session Management: Automatic session lifecycle management via KAgent REST API

Configuration

The system uses the same REST API endpoints as the ADK integration:

• POST /api/sessions - Create new sessions
• GET /api/sessions/{id} - Retrieve session and events
• POST /api/sessions/{id}/events - Append checkpoint events
• POST /api/tasks - Task management

Deployment

Use the same deployment pattern as kagent-adk samples with Docker and Kubernetes.