How to run Claude Code cheaply on a big codebase

The bill on a busy AI coding setup is mostly search and checking, most of it the expensive model doing work a cheaper one could do. This is the structure that fixes it, with every file ready to copy. Cheap models for the bulk, the top model only where it is needed, wired once.

Open a usage report on a busy AI coding setup and the spend is spread across dozens of sessions, almost all of it the expensive model running search and checks a cheaper model does just as well. The fix is structure, cheap models for the bulk and the top model only where it is needed. This post has the exact files to copy.