📓 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

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:

Protocol

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>"}'
   

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/

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

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

git status --short

git log --oneline -5

How It Differs from Manual Diary

memory/sessions/

.claude/diary/

Session Resume

When resuming after compaction, check

.claude/diary/

COMPACTION_INTERRUPTED

Configuration

Hook is registered in

.claude/settings.json

PreCompact

.claude/hooks/pre-compact.sh

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

exit 0

Hook Registry — 7 hooks across 5 events

pre-tool-notify.sh

Write|Edit|MultiEdit|Bash

pre-push.sh

Bash

post-commit.sh

Bash

post-tool-monitor.sh

Write|Edit|MultiEdit|Bash

.claude/observations/

session-start.sh

session-context-load.sh

.claude/session-context.md

session-end.sh

pre-compact.sh

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)