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' — 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; 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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