A practical, step-by-step guide to configuring Claude Code with CLAUDE.md, rules, and skills so AI-generated code matches your team's conventions in a large NestJS monorepo.
Hook: Ask Claude to "add a consumer-visible status to a booking" in an unconfigured monorepo, and it will happily edit the wrong microservice, hardcode an error string, and check user.role === 'admin'. None of that is Claude being wrong — it's Claude guessing. This guide removes the guessing.
Key Takeaways
Claude Code reads .claude/ from your git root, so one configuration governs every service in the monorepo.
Three mechanisms do the heavy lifting: CLAUDE.md (always-loaded project briefing), rules (hard prohibitions), and skills (multi-step workflows with templates).
