What Makes Something an Agent? There is a meaningful difference between calling an LLM API and building an AI agent. A single API call takes an input, produces an output, and stops. An agent does something more: it perceives a situation, decides what action to take, executes that action, observes the result, and decides what to do next. That loop, repeated until the task is complete, is what makes something an agent rather than a wrapper. The concept has deep roots in AI research, but the practical engineering of LLM-based agents has matured enormously in the past two years. Today, a competent Python developer can build a functional agent in…