Afaik, most of the coding harnesses use whether graph or different type of code indexing methods. not the RAG we know, but probably different version with a better algorithm. check: https://kilo.ai/docs/customize/context/codebase-indexing
got it. It seems that I'm not in the wrong case. Somebody talk about RAG for agents maybe not for coding harnesses but some other business. Maybe it is not suitable for coding harnesses.