Pre Compact Backup

Pre-Compact Backup Skill

When to trigger

• PreCompact hook fires (automatic)
• "save session before compact", "lưu transcript"
• "backup context", "sao lưu phiên làm việc"
• Before starting a very long multi-step task

What to do

Step 1 — Identify transcript location

Check for .claude/state/ or default Claude Code transcript paths.

Step 2 — Create backup

TIMESTAMP=$(date +%Y%m%d_%H%M%S)
BACKUP_DIR="logs/transcript_backups"
mkdir -p "$BACKUP_DIR"
# Copy current transcript if accessible
cp .claude/transcript.jsonl "$BACKUP_DIR/transcript_${TIMESTAMP}.jsonl" 2>/dev/null || true

Step 3 — Tag the backup

Write a short metadata file alongside:

{
  "timestamp": "YYYY-MM-DDThh:mm:ssZ",
  "trigger": "manual | pre-compact-hook",
  "branch": "[current-branch]",
  "last_commit": "[sha]"
}

Step 4 — Report

Backup saved: logs/transcript_backups/transcript_[timestamp].jsonl
Trigger: [manual | pre-compact-hook]
Branch: [branch]

Graceful degradation

• If transcript not accessible: log the attempt, do not error
• If logs/ does not exist: create it
• Never block compaction — backup is best-effort
• Silent failure is acceptable; noisy failure is not

Notes

This skill is informational — the actual backup is best done via a PreCompact hook wired in settings.json. This skill documents the pattern and can be invoked manually when needed.