You are building a command interface, not a programming language. Stop paying the architectural tax of a full compiler toolchain. This is part 3 of our ongoing series on safely integrating LLMs with production backends. Before diving in, you might want to read the previous part . ANTLR is a superb tool. If you are building a real language, a compiler front-end, or a complex configuration format, a parser generator is often the right choice. But many teams are not actually building a language. They are building a command surface inside an application: an admin console, a support terminal, a business rules interface, or a constrained control layer for LLM agents. In that middle ground, the problem is usually not how do we generate a parser? It is how do we turn a controlled sentence into one deterministic Java action with minimal friction? ANTLR Is Excellent at What It Was Built For ANTLR shines when you need a full parsing toolchain. In those contexts, a parser generator is not overkill.…