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:

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:

# 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

--system-event

causes messages to get lost when there's an active conversation in the main session.

Solution

Always use

--session isolated

# 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:

# 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:

# 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:

# 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

[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

# 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:

# 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

clawdbot cron list

Inspect Specific Job

clawdbot cron show <job-id>

Test Job Immediately

clawdbot cron run <job-id>

Check Logs

# 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

clawdbot gateway restart

Complete Working Examples

Daily Standup Reminder (9 AM, Mon-Fri)

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:

What did you accomplish yesterday?
What are you working on today?
Any blockers?

@alice @bob" 

--deliver --channel telegram --to "-100XXXXXXXXXX" 

--best-effort-deliver

One-Shot Reminder (20 minutes from now)

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)

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

AI Skill Market Insights

Be Part of the 0+ Developer Community

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

INCORRECT - causes timeout

For Agents

Problem 2: Messages Not Delivered

Symptoms

Root Cause

Solution

INCORRECT - messages can be lost

Verification

Problem 3: Wrong Execution Time

Symptoms

Root Cause

Solution

INCORRECT - defaults to UTC

Common Timezone IDs

Problem 4: Fallback Models Ignore Instructions

Symptoms

Root Cause

Solution

INCORRECT - relies only on system prompt

Robust Message Template

Problem 5: Job Stuck in Error State

Symptoms

Diagnosis

Check recent logs

Check gateway errors

Common Causes and Fixes

Nuclear Option

Restart gateway

Recreate with correct flags

Debugging Commands

View All Jobs

Inspect Specific Job

Test Job Immediately

Check Logs

Gateway errors

Watch logs in real-time

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

Quick Start

Manual Installation

TEAR & SHARE

Tags

Channels

Learn

Compare

Company

Problem 1: Internal
`cron`
Tool Deadlock