A portable C11 lead-processing engine that combines deterministic business rules with OpenAI-compatible LLMs. The AI interprets a natural-language message — what service the customer wants, the type of space, likely urgency, a summary, a next step, and a draft response — while the deterministic C engine verifies and controls the result. For example, if a customer writes "20 by 30 feet," the C engine calculates 600 square feet itself; it does not rely on the model to do the math. If information is missing, the lead is routed as insufficient rather than letting the AI invent details. It parses CSV leads and produces normalized JSONL, with mock and live modes.