diary

name	diary
description	Use when the user says 'save diary', 'log session', 'wrapping up', or at end of a productive session.
version	1.0.0

📓 Diary — Logging Session...

Document what was accomplished in each CC session for future recall.

Activation

When this skill activates, output:

📓 Diary — Logging session...

Then execute the protocol below.

Context Guard

Context	Status	Priority
User says "save diary", "log session", "write diary"	ACTIVE — write diary	P1
User explicitly says they're done ("that's it", "wrapping up")	ACTIVE — suggest diary if work was done	P2
Multi-agent session (Builder/Reviewer role)	DORMANT — Manager handles diary	—
Mid-session, user is actively coding	DORMANT — don't interrupt flow	—
Casual conversation, no code changes made	DORMANT — nothing to log	—
User asks to recall past sessions ("what did we do")	DORMANT — Echo handles recall, not Diary	—
User says "save project" or "handoff"	DORMANT — Project skill handles this	—
Session just started, no work yet	DORMANT — nothing to log	—

When NOT to Fire

• Do NOT fire autonomously. Only activate when the user explicitly requests it ("save diary", "log session", "wrapping up").
• Multi-agent sessions: If you are operating as Builder, Reviewer, or any non-Manager agent in a multi-agent session, do NOT fire diary. Only the Manager or a standalone session should trigger diary.
• No work done: If no meaningful changes were made (no commits, no file edits), skip diary.

Reminders

When the user asks to save a diary, keep these in mind:

Temptation	Why it matters
"Nothing important happened"	Even small decisions have context worth capturing.
"Commits capture everything"	Commits don't capture decisions, blockers, or next steps.
"Skip the handoff section"	Handoffs are the most valuable part for session continuity.

Protocol

Always use Bash for all memstack-db.py commands. Do not use PowerShell or CMD -- PowerShell mangles JSON arguments.

All JSON field values must be plain strings. Never pass arrays or objects. If multiple items (files, commits, decisions), join them as a comma-separated string.

1. Summarize the session:

   • Project name and working directory
   • Date and approximate duration
   • What was built or changed
   • Key files created or modified
   • Commits made (hashes and messages)
   • Decisions made and why
   • Problems encountered and solutions

2. Check git log for commits:

   git log --oneline -10
   

3. Format the diary entry:

   # Session Diary — {project} — {date}
   
   ## Accomplished
   - Item 1...
   
   ## Files Changed
   - path/to/file.ts — description
   
   ## Commits
   - abc1234 Message
   
   ## Decisions
   - Decision: reason
   
   ## Next Steps
   - What to do next
   
   ## Session Handoff
   **In Progress:** [what was actively being worked on when session ended]
   **Uncommitted Changes:** [list any unstaged/uncommitted work, or "None"]
   **Pick Up Here:** [exact instruction for next session — specific enough to start cold]
   **Session Context:** [anything important that isn't captured elsewhere — temp decisions, debugging state, gotchas discovered]
   

4. Save to SQLite database (primary storage):

   python "$MEMSTACK_PATH/db/memstack-db.py" add-session '{"project":"<name>","date":"<YYYY-MM-DD>","accomplished":"<bullets>","files_changed":"<bullets>","commits":"<bullets>","decisions":"<bullets>","problems":"<bullets>","next_steps":"<bullets>","duration":"<estimate>","raw_markdown":"<full text>"}'
   

5. Also save decisions as insights for cross-project search:

   python "$MEMSTACK_PATH/db/memstack-db.py" add-insight '{"project":"<name>","type":"decision","content":"<decision>","context":"Session <date>","tags":"<project>"}'
   

   CRITICAL: The field name is "content", NOT "insight". Using "insight" will fail with a missing required field error.

6. Update project context with last session date:

   python "$MEMSTACK_PATH/db/memstack-db.py" set-context '{"project":"<name>","last_session_date":"<YYYY-MM-DD>"}'
   

7. Also save markdown copy to memory/sessions/{date}-{project}.md (export format, human-readable backup)

Session File Size Management

The 500-line limit on markdown files is no longer a concern since SQLite is the source of truth. Markdown files in memory/sessions/ are now just human-readable exports. Old markdown files are preserved but not the primary storage.

Inputs

• Current session context
• Project name from working directory or config.json
• Git log for commit history

Outputs

• Session entry in SQLite database
• Insights extracted from decisions
• Markdown backup in memory/sessions/
• Brief confirmation summary

Example Usage

User: "save diary"

📓 Diary — Logging session...

Saved: memory/sessions/2026-02-18-adminstack.md

Project: AdminStack | Duration: ~2 hours
Accomplished: Built CC Monitor page, API routes, setup guide
Commits: 4 (45b4c42, d1c7e11, f6c8e18, f0e793f)
Files changed: 8

This session is now searchable via Echo.

PreCompact Hook — Automatic Compaction Diary

The diary system includes an automatic PreCompact hook that fires before Claude Code compresses the context window. This closes the gap where session context could be lost during long conversations.

Behavior

• Trigger: Fires automatically before every CC context compaction — no user action required
• Output: .claude/diary/{date}-compaction.md — one file per day, appends on multiple compactions
• Flag: Every entry includes COMPACTION_INTERRUPTED so the next session knows context was cut
• Timeout: 15 seconds — fast enough to never block compaction

What It Captures

Data	Source
Uncommitted changes	git status --short
Recent commits	git log --oneline -5
Recent shell commands	Shell history (last 5)
Recently modified files	Files modified since last git operation
Branch and project	Git branch + directory name

How It Differs from Manual Diary

	Manual Diary	PreCompact Diary
Trigger	User says "save diary"	Automatic before compaction
Content	Full narrative with decisions, handoff	Snapshot of working state
Storage	SQLite + memory/sessions/	.claude/diary/ only
Purpose	Session documentation	Context recovery after compaction

Session Resume

When resuming after compaction, check .claude/diary/ for entries with today's date. The COMPACTION_INTERRUPTED flag signals that the previous context was truncated and these files contain the lost state.

Configuration

Hook is registered in .claude/settings.json under PreCompact. Script lives at .claude/hooks/pre-compact.sh. Always exits 0 — must never block compaction.

Full Hook System (v3.3.2)

The Diary skill is part of a broader hook system that automates session lifecycle, security, and observability. All hooks follow the same defensive pattern: set -uo pipefail, SCRIPT_DIR resolution, all external commands wrapped with fallbacks, guaranteed exit 0.

Hook Registry — 7 hooks across 5 events

Event	Script	Matcher	Timeout	Purpose
PreToolUse	pre-tool-notify.sh	Write|Edit|MultiEdit|Bash	10s	TTS voice alert before approval prompts
PreToolUse	pre-push.sh	Bash (git push)	60s	Build verification + secrets scan before push
PostToolUse	post-commit.sh	Bash (git commit)	10s	Debug artifact + secrets scan after commit
PostToolUse	post-tool-monitor.sh	Write|Edit|MultiEdit|Bash	10s	Observation capture — logs tool calls to .claude/observations/
SessionStart	session-start.sh	(all)	10s	CLAUDE.md indexing, monitoring ping
SessionStart	session-context-load.sh	(all)	15s	Context injection — last 3 diary + observation summaries → .claude/session-context.md
Stop	session-end.sh	(all)	10s	Monitoring API session-complete ping
PreCompact	pre-compact.sh	(all)	15s	Auto-save diary snapshot before context compaction

Architecture Notes

• Each hook is registered as an independent entry (Option B) in settings.json, giving it its own timeout budget
• PreToolUse hooks can block tool execution (exit 2 = block). All other hooks are non-blocking
• PostToolUse observation monitor writes to .claude/observations/YYYY-MM-DD.md — daily files, append-only
• SessionStart context loader is idempotent — overwrites .claude/session-context.md on each new session
• Both .claude/observations/ and .claude/session-context.md are in .gitignore (ephemeral runtime output)
• All scripts live in .claude/hooks/ and use ${CLAUDE_PROJECT_DIR} for portable path resolution

Level History

• Lv.1 — Base: Session logging with git integration. (Origin: MemStack v1.0, Feb 2026)
• Lv.2 — Enhanced: Added YAML frontmatter, context guard, 500-line limit with archive, activation message. (Origin: MemStack v2.0 MemoryCore merge, Feb 2026)
• Lv.3 — Advanced: SQLite as primary storage, auto-extract insights from decisions, markdown as backup export. (Origin: MemStack v2.1 Accomplish-inspired upgrade, Feb 2026)
• Lv.4 — Native: CC rules integration (.claude/rules/diary.md), always-on session logging awareness without skill file read. (Origin: MemStack v3.0-beta, Feb 2026)
• Lv.5 — Handoff: Added structured Session Handoff section — in-progress work, uncommitted changes, exact pickup instructions, session context preservation. (Origin: MemStack v3.1, Feb 2026)
• Lv.6 — PreCompact: Added automatic PreCompact hook — saves working state snapshot before CC context compaction, captures uncommitted changes, recent commands, and modified files with COMPACTION_INTERRUPTED flag. (Origin: MemStack v3.3.1, Mar 2026)
• Lv.7 — Hook System: Documented full 7-hook system across 5 CC lifecycle events — PreToolUse (TTS + pre-push), PostToolUse (post-commit + observation monitor), SessionStart (Headroom + context injection), Stop, PreCompact. (Origin: MemStack v3.3.2, Mar 2026)