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Skillshub cron-mastery

Cron Mastery

install
source · Clone the upstream repo
git clone https://github.com/ComeOnOliver/skillshub
Claude Code · Install into ~/.claude/skills/
T=$(mktemp -d) && git clone --depth=1 https://github.com/ComeOnOliver/skillshub "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/LeoYeAI/openclaw-master-skills/cron-mastery" ~/.claude/skills/comeonoliver-skillshub-cron-mastery && rm -rf "$T"
OpenClaw · Install into ~/.openclaw/skills/
T=$(mktemp -d) && git clone --depth=1 https://github.com/ComeOnOliver/skillshub "$T" && mkdir -p ~/.openclaw/skills && cp -r "$T/skills/LeoYeAI/openclaw-master-skills/cron-mastery" ~/.openclaw/skills/comeonoliver-skillshub-cron-mastery && rm -rf "$T"
manifest: skills/LeoYeAI/openclaw-master-skills/cron-mastery/SKILL.md
source content

Cron Mastery

Rule #1: Heartbeats drift. Cron is precise.

This skill provides the definitive guide for managing time in OpenClaw 2026.2.15+. It solves the "I missed my reminder" problem by enforcing a strict separation between casual checks (heartbeat) and hard schedules (cron).

The Core Principle

SystemBehaviorBest ForRisk
Heartbeat"I'll check in when I can" (e.g., every 30-60m)Email checks, casual news summaries, low-priority polling.Drift: A "remind me in 10m" task will fail if the heartbeat is 30m.
Cron"I will run at exactly X time"Reminders ("in 5 mins"), daily reports, system maintenance.Clutter: Creates one-off jobs that need cleanup.

1. Setting Reliable Reminders (2026.2.15+ Standard)

Rule: Never use 

act:wait
or internal loops for long delays (>1 min). Use 
cron:add
with a one-shot 
at
schedule.

Precision & The "Scheduler Tick"

While Cron is precise, execution depends on the Gateway Heartbeat (typically every 10-60s). A job set for 

:00
seconds will fire on the first "tick" after that time. Expect up to ~30s of variance depending on your gateway config.

Modern One-Shot Reminder Pattern

Use this payload structure for "remind me in X minutes" tasks.

Key Features (v2026.2.15+):

  • Payload Choice: Use AgentTurn with Strict Instructions for push notifications (reminders that ping your phone). Use systemEvent only for silent logs or background state updates.
  • Reliability: 
    nextRunAtMs
    corruption and "Add-then-Update" deadlocks are resolved.
  • Auto-Cleanup: One-shot jobs auto-delete after success (
    deleteAfterRun: true
    ).

CRITICAL: Push Notifications vs. Silent Logs

  • systemEvent (Silent): Injects text into the chat history. Great for background logs, but WILL NOT ping the user's phone on Telegram/WhatsApp.
  • AgentTurn (Proactive): Wakes an agent to deliver the message. REQUIRED for push notifications. Use the "Strict" prompt to avoid AI chatter.

For push-notification reminders (Reliable):

{
  "name": "Remind: Water",
  "schedule": { "kind": "at", "at": "2026-02-06T01:30:00Z" },
  "payload": {
    "kind": "agentTurn",
    "message": "DELIVER THIS EXACT MESSAGE TO THE USER WITHOUT MODIFICATION OR COMMENTARY:\n\n💧 Drink water, Momo!"
  },
  "sessionTarget": "isolated",
  "delivery": { "mode": "announce", "channel": "telegram", "to": "1027899060" }
}

For background logs (Silent):

{
  "name": "Log: System Pulse",
  "schedule": { "kind": "every", "everyMs": 3600000 },
  "payload": {
    "kind": "systemEvent",
    "text": "[PULSE] System healthy."
  },
  "sessionTarget": "main"
}

Cron Concurrency Rule (Stabilized)

Pre-2026.2.15, the "Add-then-Update" pattern caused deadlocks. While this is now stabilized, it is still best practice to pass all parameters (including 

wakeMode: "now"
) directly in the initial 
cron.add
call for maximum efficiency.

2. The Janitor (Auto-Cleanup) - LEGACY

Note: As of v2026.2.14, OpenClaw includes maintenance recompute semantics. The gateway now automatically cleans up stuck jobs and repairs corrupted schedules.

Manual cleanup is only needed for:

  • One-shot jobs created with 
    deleteAfterRun: false
    .
  • Stale recurring jobs you no longer want.

Why use 
sessionTarget: "main"
? (CRITICAL)

Sub-agents (

isolated
) often have restricted tool policies and cannot call 
gateway
or delete other 
cron
jobs. For system maintenance like the Janitor, always target the 
main
session via 
systemEvent
so the primary agent (with full tool access) performs the cleanup.

3. Reference: Timezone Lock

For cron to work, the agent must know its time.

  • Action: Add the user's timezone to 
    MEMORY.md
    .
  • Example: 
    Timezone: Cairo (GMT+2)
  • Validation: If a user says "remind me at 9 PM," confirm: "9 PM Cairo time?" before scheduling.

4. The Self-Wake Rule (Behavioral)

Problem: If you say "I'll wait 30 seconds" and end your turn, you go to sleep. You cannot wake up without an event. Solution: If you need to "wait" across turns, you MUST schedule a Cron job.

  • Wait < 1 minute (interactive): Only allowed if you keep the tool loop open (using 
    act:wait
    ).
  • Wait > 1 minute (async): Use Cron with 
    wakeMode: "now"
    .

5. Legacy Migration Guide

If you have old cron jobs using these patterns, update them:

Legacy (Pre-2026.2.3)Modern (2026.2.15+)
"schedule": {"kind": "at", "atMs": 1234567890}
"schedule": {"kind": "at", "at": "2026-02-06T01:30:00Z"}
"deliver": true
in payload		Not needed - 
announce
mode handles delivery
"sessionTarget": "main"
"sessionTarget": "isolated"
(default behavior)
Manual ghost cleanup requiredOne-shots auto-delete (
deleteAfterRun: true
)
cron.update
after 
cron.add
Single-step 
cron.add
with all properties

Troubleshooting

  • "My reminder didn't fire": Check 
    cron:list
    . Verify the 
    at
    timestamp is in the future (ISO 8601 format). Ensure 
    wakeMode: "now"
    is set.
  • "Gateway Timeout (10000ms)": This happens if the 
    cron
    tool takes too long (huge job list or file lock).
    • Fix 1: Manually delete 
      ~/.openclaw/state/cron/jobs.json
      and restart the gateway if it's corrupted.
    • Fix 2: Run a manual sweep to reduce the job count.
  • "Job ran but I didn't get the message": Ensure you are using the Strict Instruction Pattern with 
    agentTurn
    + 
    announce
    mode for proactive pings.
  • "The reminder message has extra commentary": The subagent is being conversational. Use the strict prompt pattern: 
    "DELIVER THIS EXACT MESSAGE TO THE USER WITHOUT MODIFICATION OR COMMENTARY:\n\n💧 Your message here"