Chapter 10 introduced the project-level CLAUDE.md, chapter 22 showed how a single session handles compaction. This chapter closes the gap in between: how does Claude remember things that should outlast a single project or a single session?

Project CLAUDE.md vs. user-wide settings

The CLAUDE.md from chapter 10 lives in the project folder and only applies there - for the recipe planner, for example, the rule "storage is a JSON file, no database". But some preferences don't apply to just one project, they apply to you personally, no matter which project you're working in: for example "Always answer me in German" or "Always write commit messages in the imperative mood, not past tense". For exactly these kinds of personal, cross-project preferences, you can set up a user-wide configuration in addition to the project CLAUDE.md, which applies regardless of which project folder is currently open.

The difference in practice

• Project-level (CLAUDE.md in the project folder, chapter 10): tech stack, conventions, and rules that apply only to this one specific project - for example the recipe planner.
• User-wide (personal settings): preferences that apply to you as a person in every project, regardless of what you're currently working on.

A good rule of thumb for deciding where a rule belongs: would a new teammate joining this exact project also need the same rule? Then it belongs in the project CLAUDE.md. Is it more about your own personal way of working, which would apply in a completely different project too? Then it belongs in your user-wide settings.

How knowledge accumulates over time

Across many sessions, small insights inevitably pile up that are worth capturing - a design decision that turned out to be the right call, a pitfall to avoid next time, a preference that crystallised while working together. Rather than hoping you'll remember it yourself in a later session, it's worth actively capturing such insights - depending on whether they're project-specific, into the project CLAUDE.md, otherwise into your personal, user-wide notes.

> We just decided that the category list in the recipe planner stays deliberately fixed to three values (see chapter 18). Please add a short note to the project's CLAUDE.md, so this doesn't come up for debate again later.

With context window, compaction, and memory covered, you now have a complete picture of how Claude Code handles knowledge over time. The last two chapters of this block turn to practical collaboration: first with git, then within a team.