---
published: true
id: claude-md
title: CLAUDE.md
description: Knowledge captured in João Lopes' learning graph.
tags:
- claude-code
- ai-engineering
- behavioral-modeling
locale: en
resource: https://joaolopes.dev.br/knowledge/concepts/en/claude-md/
created: '2026-03-19'
---

# CLAUDE.md
The file format for instructions in Claude Code, loaded into the context window at session start to give the model persistent context.

## Definition
CLAUDE.md is a plain markdown file that Claude Code loads at session start to provide persistent instructions. Files live at four scopes: managed policy (org-wide), user (~/.claude/CLAUDE.md), project (repo root), and subdirectory (loaded on demand), with more specific scopes taking precedence. CLAUDE.md is not enforcement — the instructions are loaded into the model's context, but the model may not follow them. For enforcement, see hooks.

## Source
- [Manage Claude's memory - Claude Code Docs](https://docs.anthropic.com/en/docs/claude-code/memory)

## Related
- [Instructions](/concepts/en/instructions.md)
- [Hooks](/concepts/en/hooks.md)
- behavioral-modeling
- [Context Window](/concepts/en/context-window.md)