Anatomy of the .claude/ Folder

The .claude folder is the control center for how Claude behaves in your project — it holds your instructions, your custom commands, your permission rules, and Claude's memory across sessions.

Apr 10 • 8 read time • From Thuc Pham

Two folders, not one

Before diving in, one thing worth knowing upfront: there are actually two .claude directories, not one. The project-level folder holds team configuration. The global ~/.claude/ folder holds personal preferences and machine-local state.

CLAUDE.md: Claude's instruction manual

Whatever you write in CLAUDE.md, Claude will follow. Keep it under 200 lines — past that, instruction adherence drops.

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# Development

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- Use pnpm, not npm

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- Run tests with `pnpm test`

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- TypeScript strict mode is on

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# Architecture

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- Monorepo (Turborepo), packages under /packages

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- API lives in /apps/api (Fastify)

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- Web lives in /apps/web (Next.js 15)