First Setup: What Changes with a Single CLAUDE.md
This is chapter 2 of my book **Building Autonomous AI Agents with Claude Code * — a field guide to turning Claude Code from a coding assistant into an agent that remembers, verifies its own work, and knows when to stop. Everything below is from a system I actually run every day on one Windows PC.* 1. CLAUDE.md Is a "Contract Read Every Time" Every time Claude Code starts a session, it injects the…
Every time Claude Code initiates a new session, it incorporates the global settings stored in ~/.claude/CLAUDE.md along with the specific project's CLAUDE.md file. These global settings and project-specific rules are automatically attached to every conversation, making the rules a permanent part of the AI's behavior. This feature is beneficial as it eliminates the need to repeat essential instructions, but it also poses a risk - too many rules can cause the AI to overlook the most critical ones.
If a rule set grows beyond 1,300 lines, the AI may begin to disregard important rules. To prevent this, it's essential to maintain a concise CLAUDE.md file containing only the most crucial rules, while moving less critical rules to separate files. This three-layer structure - a global CLAUDE.md file, rule fragments in ~/.claude/rules/*.md, and specific rules for different topics - helps manage the size of the rule set.
Each rule should be verifiable through behavior, have a clear one-line reason, and propose a replacement behavior instead of just a prohibition. To manage the growth of rules, monitor for multiple rules on the same topic, rules containing "as an exception", and ignored rules. Instead of rewriting a rule, consider transforming it into a "hook" that guides the AI's behavior.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
