Model Wrapping vs Opt-In Calls: How Vercel AI SDK and Genkit Approach Middleware

As Gen AI frameworks mature, middleware design becomes crucial for building scalable, maintainable applications. Vercel AI SDK and Genkit represent two distinct philosophies—one wraps models transparently, the other requires explicit opt-in per call—each suited to different architectural needs. Understanding these differences enables developers to choose the right approach or strategically combine both frameworks in the same codebase.