Boot Resume

Zero-cooperation session recovery after gateway restart. No checkpoints, no hooks, no agent involvement — just reads the evidence and picks up where it left off. Use when: the gateway was killed mid-task (SIGTERM, OOM, SIGKILL, crash), sessions were interrupted mid-turn with tool calls in progress, the agent stopped responding after a restart, a user reports the agent went silent after a crash, you need to manually check whether any sessions need recovery, or you want automatic resume without writing any checkpoint logic.

Zero-cooperation session recovery after gateway restart. No checkpoints, no hooks, no agent involvement — just reads the evidence and picks up where it left off.

Problem

When the gateway restarts, any in-flight agent turn dies mid-execution. Session history is preserved on disk, but the agent doesn't know it needs to continue. Users must manually tell each interrupted session to resume.

Checkpoint-based approaches require the agent to save state before dying. Unexpected kills (SIGKILL, OOM, power loss) bypass this entirely.

Solution

A deterministic shell script runs on every gateway start via systemd ExecStartPost. No LLM in the detection loop.

┌─────────┐     ┌──────────┐     ┌──────────┐
│  Scan   │ ──▶ │  Detect  │ ──▶ │  Resume  │
│sessions │     │  JSONL   │     │ cron add │
│ .json   │     │  tail    │     │--sys-evt │
└─────────┘     └──────────┘     └──────────┘

1. Scan — finds sessions updated within the last 20 minutes
2. Detect — reads the last 5 JSONL lines to classify session state
3. Resume — schedules a one-shot openclaw cron add --system-event --wake now to inject a continuation prompt

Key insight: the JSONL session files already contain all the evidence needed to detect an interruption — no pre-save required.

Detection Rules

Last JSONL Entry	Status	Meaning
toolResult	INTERRUPTED	Tool returned, agent never processed it
assistant (empty text)	INTERRUPTED	Tool call dispatched, killed before response
user (non-trivial)	INTERRUPTED	Message received, never processed
assistant (with text)	COMPLETE	Session ended normally — skip
user (trivial: "ok", emoji)	TRIVIAL	No meaningful request pending — skip

Install

One command

bash {baseDir}/install.sh

Deploys three components:

• boot-resume-check.sh → ~/.openclaw/workspace/scripts/
• boot-resume.conf → systemd drop-in (triggers script on every gateway start)
• boot-resume-wake.service → systemd user service (triggers script on system wake from sleep/suspend)

Manual

cp {baseDir}/scripts/boot-resume-check.sh ~/.openclaw/workspace/scripts/
chmod +x ~/.openclaw/workspace/scripts/boot-resume-check.sh

mkdir -p ~/.config/systemd/user/openclaw-gateway.service.d
cp {baseDir}/templates/boot-resume.conf ~/.config/systemd/user/openclaw-gateway.service.d/
cp {baseDir}/templates/boot-resume-wake.service ~/.config/systemd/user/

systemctl --user daemon-reload
systemctl --user enable boot-resume-wake.service

Verify

systemctl --user restart openclaw-gateway
sleep 20
cat /tmp/openclaw/boot-resume.log

Expected output:

[boot-resume] now=... cut=... (20min window)
[boot-resume] scanning agent: main
[boot-resume] candidates: 0 (agent=main)
[boot-resume] done

Test

1. Send a message that triggers a multi-step task (web search, code analysis, etc.)
2. Wait for the agent to start processing (tool calls in flight)
3. systemctl --user restart openclaw-gateway
4. Agent resumes automatically within ~35 seconds

Slash Command

When invoked as /boot-resume, run the script with --no-wait to skip the startup delay:

bash {baseDir}/scripts/boot-resume-check.sh --no-wait

Report results to the user: which sessions were resumed, or that none were found.

Configuration

Variable	Default	Description
WINDOW_MINUTES	20	How far back to scan for interrupted sessions
DELAY	20s	Delay before injecting the resume event

Edit at the top of scripts/boot-resume-check.sh.

Features

• Dual trigger — covers both gateway restart (ExecStartPost) and system sleep/wake (systemd sleep.target)
• Multi-agent support — scans all agents under ~/.openclaw/agents/, not just main
• Smart filtering — skips system, heartbeat, cron, and subagent sessions automatically
• Deduplication — respects restart-resume.json to avoid double-resuming planned restarts
• Log rotation — auto-truncates log at 1000 lines
• Error visibility — Python and cron errors are logged, not swallowed
• Unique job names — timestamp-based to prevent conflicts on rapid restarts

Comparison

Approach	Pre-save required	Survives SIGKILL	LLM-free
Checkpoint / snapshot files	Yes	No	No
Pre-restart state dump	Yes	No	No
Session history replay	Yes	Partial	No
Post-hoc JSONL detection (this skill)	No	Yes	Yes

Logs

Output: /tmp/openclaw/boot-resume.log

Each run logs: timestamp, scan window, candidate count, per-session status, and whether a resume job was armed.

Limitations

• 20-minute scan window (configurable) — sessions idle longer than this are not resumed
• Resume prompt is generic — the agent relies on session context for continuity
• Telegram/Discord message queues already handle unprocessed incoming messages — this skill targets mid-execution interruptions
• Requires systemd (Linux); macOS users need manual launchd setup

Uninstall

rm ~/.config/systemd/user/openclaw-gateway.service.d/boot-resume.conf
systemctl --user disable boot-resume-wake.service 2>/dev/null
rm ~/.config/systemd/user/boot-resume-wake.service
systemctl --user daemon-reload
rm ~/.openclaw/workspace/scripts/boot-resume-check.sh
rm -rf ~/.openclaw/workspace/skills/boot-resume