EZ Cronjob

Fix common cron job failures in Clawdbot/Moltbot - message delivery issues, tool timeouts, timezone bugs, and model fallback problems.

Isaac Zarzuri@promadgenius

Install

openclaw skills install @promadgenius/ez-cronjob

Cron Job Reliability Guide

A comprehensive guide to diagnosing and fixing cron job issues in Clawdbot/Moltbot. This skill documents common failure patterns and their solutions, learned through production debugging.

When to Use This Skill

Use this skill when:

Scheduled messages aren't being delivered
Cron jobs show "error" status
Messages arrive at wrong times (timezone issues)
The agent times out when using the cron tool
Fallback models ignore instructions and call tools unexpectedly

Quick Reference

The Golden Rule

Always use these flags together for reliable delivery:

bash

clawdbot cron add \
  --name "my-job" \
  --cron "0 9 * * 1-5" \
  --tz "America/New_York" \
  --session isolated \
  --message "[INSTRUCTION: DO NOT USE ANY TOOLS] Your prompt here" \
  --deliver --channel telegram --to "CHAT_ID" \
  --best-effort-deliver

Essential Flags Explained

Flag	Purpose	Why It Matters
`--session isolated`	Creates dedicated session	Prevents message loss in busy conversations
`--tz "TIMEZONE"`	Sets explicit timezone	Avoids UTC confusion
`--deliver`	Sends to channel	Required for Telegram/WhatsApp
`--best-effort-deliver`	Don't fail on delivery error	Graceful degradation

Problem 1: Internal `cron` Tool Deadlock

Symptoms

Agent times out (10s) when calling cron list or cron add
Error: "Tool execution timed out"
Gateway logs show 80s+ response times

Root Cause

The internal cron tool creates a deadlock between the agent process and gateway.

Solution

Never use the cron tool directly. Use exec (or bash) instead:

bash

# CORRECT - uses exec to bypass deadlock
exec: clawdbot cron list
exec: clawdbot cron add --name "reminder" --at "+5m" --message "Hello"

# INCORRECT - causes timeout
cron list        # DO NOT USE
cron add ...     # DO NOT USE

For Agents

If you're an AI agent reading this: when the user asks you to manage cron jobs, always use the exec/bash tool to run clawdbot cron commands. Never invoke the cron tool directly.

Problem 2: Messages Not Delivered

Symptoms

Job shows "ok" status but message never arrives
Works in testing but fails on schedule
Intermittent delivery

Root Cause

Using --session main or --system-event causes messages to get lost when there's an active conversation in the main session.

Solution

Always use --session isolated:

bash

# CORRECT - isolated session, guaranteed delivery
clawdbot cron add \
  --name "daily-standup" \
  --cron "0 9 * * 1-5" \
  --session isolated \
  --deliver --channel telegram --to "-100XXXXXXXXXX"

# INCORRECT - messages can be lost
clawdbot cron add \
  --name "daily-standup" \
  --session main \
  --system-event \
  ...

Verification

After creating a job, test it:

bash

# Run the job immediately to verify delivery
clawdbot cron run <job-id>

Problem 3: Wrong Execution Time

Symptoms

Job runs 4-5 hours early or late
Schedule shows correct time but execution is off
Works correctly sometimes, fails other times

Root Cause

Missing timezone specification defaults to UTC.

Solution

Always specify timezone explicitly:

bash

# CORRECT - explicit timezone
clawdbot cron add \
  --cron "0 9 * * 1-5" \
  --tz "America/New_York" \
  ...

# INCORRECT - defaults to UTC
clawdbot cron add \
  --cron "0 9 * * 1-5" \
  ...

Common Timezone IDs

Region	Timezone ID
US Eastern	`America/New_York`
US Pacific	`America/Los_Angeles`
UK	`Europe/London`
Central Europe	`Europe/Berlin`
India	`Asia/Kolkata`
Japan	`Asia/Tokyo`
Australia Eastern	`Australia/Sydney`
Brazil	`America/Sao_Paulo`
Bolivia	`America/La_Paz`

Problem 4: Fallback Models Ignore Instructions

Symptoms

Primary model works correctly
When fallback activates, agent calls tools unexpectedly
Agent tries to use exec, read, or other tools when it shouldn't

Root Cause

Some fallback models (especially smaller/faster ones) don't follow system instructions as strictly as primary models.

Solution

Embed instructions directly in the message:

bash

# CORRECT - instruction embedded in message
clawdbot cron add \
  --message "[INSTRUCTION: DO NOT USE ANY TOOLS. Respond with text only.] 
  
  Generate a motivational Monday message for the team."

# INCORRECT - relies only on system prompt
clawdbot cron add \
  --message "Generate a motivational Monday message for the team."

Robust Message Template

text

[INSTRUCTION: DO NOT USE ANY TOOLS. Write your response directly.]

Your actual prompt here. Be specific about what you want.

Problem 5: Job Stuck in Error State

Symptoms

Job status shows "error"
Subsequent runs also fail
No clear error message

Diagnosis

bash

# Check job details
clawdbot cron show <job-id>

# Check recent logs
tail -100 /tmp/clawdbot/clawdbot-$(date +%Y-%m-%d).log | grep -i cron

# Check gateway errors
tail -50 ~/.clawdbot/logs/gateway.err.log

Common Causes and Fixes

Cause	Fix
Model quota exceeded	Wait for quota reset or switch model
Invalid chat ID	Verify channel ID with `--to`
Bot removed from group	Re-add bot to Telegram group
Gateway not running	`clawdbot gateway restart`

Nuclear Option

If nothing works:

bash

# Remove the problematic job
clawdbot cron rm <job-id>

# Restart gateway
clawdbot gateway restart

# Recreate with correct flags
clawdbot cron add ... (with all recommended flags)

Debugging Commands

View All Jobs

bash

clawdbot cron list

Inspect Specific Job

bash

clawdbot cron show <job-id>

Test Job Immediately

bash

clawdbot cron run <job-id>

Check Logs

bash

# Today's logs filtered for cron
tail -200 /tmp/clawdbot/clawdbot-$(date +%Y-%m-%d).log | grep -i cron

# Gateway errors
tail -100 ~/.clawdbot/logs/gateway.err.log

# Watch logs in real-time
tail -f /tmp/clawdbot/clawdbot-$(date +%Y-%m-%d).log | grep --line-buffered cron

Restart Gateway

bash

clawdbot gateway restart

Complete Working Examples

Daily Standup Reminder (9 AM, Mon-Fri)

bash

clawdbot cron add \
  --name "daily-standup-9am" \
  --cron "0 9 * * 1-5" \
  --tz "America/New_York" \
  --session isolated \
  --message "[INSTRUCTION: DO NOT USE ANY TOOLS. Write directly.]

Good morning team! Time for our daily standup.

Please share:
1. What did you accomplish yesterday?
2. What are you working on today?
3. Any blockers?

@alice @bob" \
  --deliver --channel telegram --to "-100XXXXXXXXXX" \
  --best-effort-deliver

One-Shot Reminder (20 minutes from now)

bash

clawdbot cron add \
  --name "quick-reminder" \
  --at "+20m" \
  --delete-after-run \
  --session isolated \
  --message "[INSTRUCTION: DO NOT USE ANY TOOLS.]

Reminder: Your meeting starts in 10 minutes!" \
  --deliver --channel telegram --to "-100XXXXXXXXXX" \
  --best-effort-deliver

Weekly Report (Friday 5 PM)

bash

clawdbot cron add \
  --name "weekly-report-friday" \
  --cron "0 17 * * 5" \
  --tz "America/New_York" \
  --session isolated \
  --message "[INSTRUCTION: DO NOT USE ANY TOOLS.]

Happy Friday! Time to wrap up the week.

Please share your weekly highlights and any items carrying over to next week." \
  --deliver --channel telegram --to "-100XXXXXXXXXX" \
  --best-effort-deliver

Checklist for New Cron Jobs

Before creating any cron job, verify:

Using exec: clawdbot cron add (not the cron tool directly)
--session isolated is set
--tz "YOUR_TIMEZONE" is explicit
--deliver --channel CHANNEL --to "ID" for message delivery
--best-effort-deliver for graceful failures
Message starts with [INSTRUCTION: DO NOT USE ANY TOOLS]
Tested with clawdbot cron run <id> after creation

Related Resources

Skill authored by Isaac Zarzuri. Based on production debugging experience with Clawdbot/Moltbot.

EZ Cronjob

Install

Cron Job Reliability Guide

When to Use This Skill

Quick Reference

The Golden Rule

Essential Flags Explained

Problem 1: Internal cron Tool Deadlock

Symptoms

Root Cause

Solution

For Agents

Problem 2: Messages Not Delivered

Symptoms

Root Cause

Solution

Verification

Problem 3: Wrong Execution Time

Symptoms

Root Cause

Solution

Common Timezone IDs

Problem 4: Fallback Models Ignore Instructions

Symptoms

Root Cause

Solution

Robust Message Template

Problem 5: Job Stuck in Error State

Symptoms

Diagnosis

Common Causes and Fixes

Nuclear Option

Debugging Commands

View All Jobs

Inspect Specific Job

Test Job Immediately

Check Logs

Restart Gateway

Complete Working Examples

Daily Standup Reminder (9 AM, Mon-Fri)

One-Shot Reminder (20 minutes from now)

Weekly Report (Friday 5 PM)

Checklist for New Cron Jobs

Related Resources

Related skills

Problem 1: Internal `cron` Tool Deadlock