Why “which API do I call?” is the wrong question in the LLM era

For decades, we have adapted to software. We learned shell commands, memorized HTTP method names and wired together SDKs. Each interface assumed we would speak its language. In the 1980s, we typed 'grep', 'ssh' and 'ls' into a shell; by the mid-2000s, we were invoking REST endpoints like GET /users; by the 2010s, we imported SDKs (client.orders.list()) so we didn’t have to think about HTTP. But underlying each of those steps was the same premise: Expose capabilities in a structured form so others can invoke them.

But now we are entering the next interface paradigm. Modern LLMs are challenging the notion that a user must choose a function or remember a method signature. Instead of “Which API do I call?” the question becomes: “What outcome am I trying to achieve?” In other words, the interface is shifting from code → to language. In this shift, Model Context Protocol ...