XERJ.code — reference coding

An agent that does not know an API guesses, runs, fails, and guesses again. Each lap costs output tokens, which are the expensive kind. This skill replaces laps with a lookup: clone the repositories that already contain a correct implementation, index them with XERJ, and retrieve the passage before writing.

The trade is deliberate. Retrieval spends input tokens, which are cheaper per token and cacheable; loops spend output tokens. See COSTS.md for the arithmetic and for the conditions under which this trade loses.