assistant-ui-langgraph-fastapi

A demonstration project that combines LangGraph, assistant-stream, and FastAPI to create an AI agent with a modern UI. The project uses assistant-ui and Next.js.

Overview

This project showcases:

• A LangGraph agent running on a FastAPI
• Real-time response streaming to the frontend using assistant-stream
• A modern chat UI built with assistant-ui and Next.js
• Demonstrate how to integrate external tools and APIs

Prerequisites

• Python 3.11
• Node.js v20.18.0
• npm v10.9.2
• Yarn v1.22.22

Project Structure

assistant-ui-langgraph-fastapi/
├── backend/         # FastAPI + assistant-stream + LangGraph server
└── frontend/        # Next.js + assistant-ui client

Setup Instructions

Set up environment variables

Go to ./backend and create .env file. Follow the example in .env.example.

Backend Setup

The backend is built using the LangChain CLI and utilizes LangGraph's create_react_agent for agent creation.

cd backend
poetry install
poetry run python -m app.server

Frontend Setup

The frontend is generated using the assistant-ui CLI tool.

cd frontend
yarn install
yarn dev

Credits

Based on https://github.com/hminle/langserve-assistant-ui