CC4E #5: The Best Personal Assistant Remembers Things About You
Author: Hannah Stulberg | Published: 2026-02-14
A deep dive on CLAUDE.md files – onboarding documents that auto-load so Claude starts every session already briefed. Solves the “Groundhog Day employee” problem.
How CLAUDE.md Files Work
- Plain text markdown files, named exactly
CLAUDE.md(all caps required) - Auto-load at session start from the current folder all the way up to the root
- Hierarchical loading: deeper files layer more specific context on top of general context
- Conflict resolution: more specific (deeper) file wins
- Applies equally to AGENTS.md (Cursor, Antigravity) – concepts are tool-agnostic
Critical Trade-Off
Every line in a CLAUDE.md file consumes thinking room from the start. More context loaded = less room to think = lower quality output. Be intentional about what goes in.
- If CLAUDE.md files push context to 10-15% before you start, they’re too heavy
- Practical ceiling: ~150 total instructions across all loaded files (Claude Code’s system prompt uses ~50, leaving ~100-150)
Folder Structure Controls Context
| Level | Location | Contains |
|---|---|---|
| Level 0 | ~/CLAUDE.md | Personal working style, portable across jobs |
| Level 1 | ~/Acme/CLAUDE.md | Company context, role, team, areas |
| Level 2 | ~/Acme/Marketing/CLAUDE.md | Domain-specific (brand voice, processes) |
| Level 3 | ~/Acme/Marketing/Q1Campaign/CLAUDE.md | Project goals, timeline, decisions, status |
Only create a CLAUDE.md when you have context that is (1) specific to that level and (2) needed across multiple sessions.
Four Types of Content
- Document index – map of what’s where so Claude doesn’t search blindly. Can use
@imports for auto-loading specific files - The people involved – names, roles, relationships at the relevant level
- What this is about – identity, goals, key facts
- How you want things done – workflows, processes, preferences, guardrails
What Does NOT Belong
- Passwords, API keys, sensitive data
- Context that belongs at a different level
- Info that changes so frequently it’ll be stale next session
- Templates (use custom slash commands instead – loaded on demand)
- Litmus test: if a piece of context isn’t relevant to the vast majority of sessions where that file loads, it doesn’t belong
Three Methods to Write Them
| Method | When to use | How |
|---|---|---|
| Plan mode interview | Context lives in your head | Plan mode, Claude interviews you, you answer conversationally |
| Load docs, then generate | You have existing documents | Save docs into the folder, ask Claude to read them and draft |
| Generate from a session | Just finished productive work | Ask Claude to capture durable context from the session |
Claude drafts, you edit. Always review – Claude may include session-specific details that aren’t durable.
Maintenance
- After big sessions: ask Claude if CLAUDE.md needs updating
- When you keep re-explaining the same thing: make it permanent
- Signs a file needs trimming: longer than when created, finished project details, multiple projects crammed in one file
- CLAUDE.md files load at session start. Mid-session edits require re-reading the file,
/clear, or a new session