Session Hygiene

Prevent sessions.json bloat from accumulating isolated sessions (hooks, crons, subagents). Sets up a cron to archive stale sessions to daily JSONL files and keep sessions.json lean. Use when sessions.json grows large, the gateway becomes slow or unresponsive, or as preventive maintenance on any OpenClaw instance with hooks or crons. Related to openclaw/openclaw#15225.

OpenClaw's session store (sessions.json) grows unbounded — every hook, cron, and subagent invocation creates a session entry that never gets cleaned up. Heavy setups (webhooks + crons) can hit 200MB+ and 7000+ sessions within weeks, causing gateway slowdowns and unresponsiveness.

This skill sets up automated archive-and-rotate to keep sessions.json lean while preserving session history.

Quick Setup

Create a cron that runs every 6 hours:

cron(action: "add", job: {
  name: "Session Archive & Cleanup",
  schedule: { kind: "cron", expr: "0 */6 * * *", tz: "America/Los_Angeles" },
  sessionTarget: "isolated",
  payload: {
    kind: "agentTurn",
    message: "Archive and clean up stale sessions. Run the script: python3 <skill-dir>/scripts/archive_sessions.py",
    timeoutSeconds: 60
  },
  delivery: { mode: "announce", channel: "slack" }
})

Adjust the timezone and delivery channel to match your setup.

What It Does

1. Archive: Sessions older than 48 hours get moved to sessions-archive/YYYY-MM-DD.jsonl (one JSON line per session, grouped by date)
2. Protect: agent:main:main is never removed
3. Rotate: Archive files older than 30 days are deleted
4. Report: Logs how many sessions were archived, how many remain, and file sizes

Manual Run

For an immediate cleanup (e.g., if sessions.json is already bloated):

python3 <skill-dir>/scripts/archive_sessions.py

Or for a one-time aggressive purge of sessions older than N hours:

python3 <skill-dir>/scripts/archive_sessions.py --max-age-hours 1

Tuning

Parameter	Default	Notes
--max-age-hours	48	How old a session must be before archiving
--archive-retention-days	30	How long to keep archive JSONL files
--sessions-path	Auto-detected	Path to sessions.json
--dry-run	off	Preview what would be archived without changing anything

Sizing Estimates

Sessions/day	48h retention	sessions.json size
50	~100 sessions	~3MB
100	~200 sessions	~6MB
200	~400 sessions	~12MB

Without this skill, the same setup would grow to 200MB+ within a month.