Session Memory

Diary entries capture what happened in each Claude Code session so context survives across conversations and machines.

How it works

A PreCompact hook fires automatically before Claude Code compacts a long conversation. It outputs an instruction that Claude reads and uses to write a structured diary entry to .claude/memory/diary/ in the current project.

Entries use the format YYYY-MM-DD-session-N.md and contain:

• Task Summary — what the user was trying to accomplish
• Work Done — bullet list of completed items
• Design Decisions — key choices and the WHY behind them
• Challenges Encountered — errors, failed approaches, user corrections
• Solutions Applied — how problems were resolved
• User Preferences Observed — code style, workflow preferences, language protocol
• Context — project type, languages, frameworks used in the session

Diary entries are per-project (stored in the project's .claude/memory/diary/), never committed to git (.gitignore excludes *.md in that directory), and never shared between projects.

Installation

The install-claude-commands.ps1 installer handles everything automatically:

1. Copies pre-compact.sh to ~/.claude/hooks/
2. Adds a PreCompact block to ~/.claude/settings.json

This runs on every machine where you run the installer — including work laptops.

To verify the hook is registered, run /hooks inside Claude Code and look for PreCompact | auto.

Manual diary entry

For short but important sessions where /compact never fires:

Create a diary entry for this session and save it to .claude/memory/diary/

Claude will write the entry using the same format as the automatic hook.

/reflect-diary

After accumulating a few entries, run /reflect-diary to analyse patterns:

/reflect-diary
/reflect-diary last 5
/reflect-diary from 2026-05-01 to 2026-05-31

The skill reads the diary entries, identifies preferences and decisions that appear in 2 or more entries (strong pattern: 3+), cross-checks against the existing project-profile.md, and presents proposed updates.

Nothing is written automatically. You approve each proposed change individually before it is applied to project-profile.md.

What is not automated

• Updates to CLAUDE.md — always manual, to prevent drift
• Cross-project pattern detection — each project's diary is independent
• Processed-entry tracking — low volume per project makes a log file unnecessary