DeepSeek has emerged as a serious contender in the large language model space, offering open-weight models that deliver strong performance at a fraction of the cost of comparable alternatives. For developers building AI-powered web applications, DeepSeek API integration with React and Next.js provides a production-viable path that uses an OpenAI-compatible endpoint structure, meaning existing tooling and SDK knowledge transfers directly. This tutorial walks through building a complete Next.js application with a React chat interface powered by the DeepSeek API, covering everything from project scaffolding to streaming responses to production deployment. How to Integrate the DeepSeek API with React and Next.js Scaffold a Next.js App Router project with TypeScript and install the OpenAI SDK. Store your DeepSeek API key in .env.local and validate it at startup. Create a shared DeepSeek client utility that points the OpenAI SDK at the DeepSeek base URL.…