Large Language Models (LLMs) like OpenAI's GPT-4 and Mistral have revolutionized how developers build intelligent applications. Whether you're creating a chatbot, code assistant, or content generator, integrating LLMs into your Next.js project is easier than ever in 2025. In this guide, we’ll walk you through how to create an LLM-powered app using Next.js, with API routes, edge functions, and server-side streaming—all with best practices in mind.