Simple stdin chatbot using LangChain with tool calling (OpenRouter). Installation 1pip install langchain langchain-openai python-dotenv Environment Setup 1# .env 2OPENROUTER_API_KEY=your_api_key_here 3OPENROUTER_MODEL=openai/gpt-4-turbo-preview Basic Chatbot 1import os 2from dotenv import load_dotenv 3from …