Put nested CLAUDE.md files in subdirectories for local context

The problem

One giant root CLAUDE.md tries to document every subsystem, gets ignored mid-session, and wastes tokens on rules that do not apply to the current files.

The hack

Keep global rules in root CLAUDE.md under ~200 lines. Add `src/payments/CLAUDE.md` (and similar) with module-specific invariants — Claude loads nested files when it touches that directory.

Why it works

Widely confirmed by HN power users and Anthropic’s memory model: nested CLAUDE.md is automatic, path-local context. Pair with path-scoped `.claude/rules/` when you want frontmatter-controlled loading.

Setup

1. Trim root CLAUDE.md to team-wide rules only. 2. Create `src/<area>/CLAUDE.md` with that area’s invariants, commands, and pitfalls. 3. Ask Claude to edit a file in that area and run `/memory` or `/context` to confirm local memory loaded. 4. Avoid duplicating the same prose in root and nested files.

Source

Related

• → Keep CLAUDE.md under 200 lines so rules actually stick
• → Load rules only when files match with .claude/rules