Lesson 5 / 7 · ~10 minutes

Context: CLAUDE.md
and project memory

Day two's unpleasant surprise: you open a new conversation and Claude remembers nothing from yesterday. It's not a bug. Every session starts with a clean slate. The solution is a file called CLAUDE.md.

CLAUDE.md: a notebook it reads by itself

If a CLAUDE.md file exists in the project folder, Claude Code reads it automatically at the start of every session. It's the note yesterday's session leaves for today's. It should contain:

  • What the project is: a sentence or two.
  • How it runs and deploys: where to click, what to type.
  • Rules: what not to touch, what language to write in.
  • Current state: what's done, what's in progress.

And the best part: you don't have to write it yourself. At the end of a session, say: “Write into CLAUDE.md what we did today and what's unfinished.” Claude keeps its own notebook, you just check it now and then.

Long sessions: when to start fresh

A conversation has limited “working memory” (context). When a session gets too long, replies slow down and Claude starts forgetting what happened at the beginning. The golden rule:

Thing finished → commit → note in CLAUDE.md → feel free to start a new session. A new session with a good CLAUDE.md knows everything important about the project, and thinks fast.

Builder: what belongs in CLAUDE.md?

Eight blocks for a fictional café website. Click the four that belong in CLAUDE.md, then evaluate.

“Project: website for Café Amora. Static HTML, pages in the web/ folder, styles in assets/style.css.”

Belongs: what the project is and where things live. The first thing a new session needs.

“Hosting password: cafeAmora2026!”

Doesn't belong. Never put passwords in CLAUDE.md (lesson 4). The file travels with the project everywhere.

“Run: open web/index.html in the browser. Deploy: tell Claude 'deploy the site' and it knows how.”

Belongs: how the project runs and deploys. Exactly what you'd otherwise explain from scratch every day.

“June 3rd we tried a blue background, then green, then light blue, then blue again, Kate wanted beige…”

Doesn't belong. A diary of experiments takes up space and doesn't help. History lives in git, so keep only the current state and standing decisions in CLAUDE.md.

“Rules: write copy in English. Don't change anything in the photos-original/ folder.”

Belongs: rules and prohibitions. Claude will respect them in every session without reminders.

“Claude, please be maximally creative, thorough, and think like a world-class designer.”

Doesn't belong. Empty incantations improve nothing. Spend context space on facts about the project.

“State: homepage and menu done. In progress: reservation form, submission missing.”

Belongs: current state and unfinished work. A new session knows exactly where to pick up.

The entire HTML of the homepage, copied into CLAUDE.md “just in case”.

Doesn't belong. Code lives in files and Claude reads it by itself. A copy in CLAUDE.md only goes stale and eats context.

Summary

  • CLAUDE.md = project memory. Claude reads it automatically at session start.
  • It holds: what the project is, how it runs, rules, current state. Not: passwords, code, diaries.
  • Delegate the writing: “write into CLAUDE.md what we did today”.
  • Long sessions fade: finish, commit, note, new session.
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