Last week, I ran a small experiment. I wanted to see how well GPT-4 could interact with a real-world API without much hand-holding. Nothing complicated. No multi-agent workflows. No orchestration frameworks. Just a simple task that thousands of applications perform every day. Send an email through SendGrid. The goal was straightforward. Give the model the context it needed, let it generate the request, and see how far it could get. What happened next surprised me. GPT-4 generated a request containing several parameters that looked completely valid. The payload was structured correctly. The field names were descriptive. Everything looked professional. The only problem was that those parameters did not exist in the SendGrid API. The request failed immediately. At first, I thought this was a model problem. After all, hallucinations are a well-known limitation of language models. **But the more I experimented with APIs, agents, and production workflows, the more I realized something deeper.…