Cron

Cron Jobs

Schedule tasks that send messages to the agent at specified times. Jobs are scheduled immediately when created.

Quick Reference

lettabot-cron list                    # List all jobs
lettabot-cron create [options]        # Create job
lettabot-cron delete ID               # Delete job
lettabot-cron enable ID               # Enable job
lettabot-cron disable ID              # Disable job

Create a Job

lettabot-cron create \
  --name "Morning Briefing" \
  --schedule "0 8 * * *" \
  --message "Good morning! Review tasks for today." \
  --deliver telegram:123456789

Options:

• -n, --name - Job name (required)
• -s, --schedule - Cron expression (required)
• -m, --message - Prompt sent to the agent when the job fires (required)
• -d, --deliver - Auto-deliver the agent's response to a channel (format: channel:chatId). Without this flag, the job runs in silent mode (see below).
• --disabled - Create in disabled state

Silent Mode vs Delivery Mode

Cron jobs run in one of two modes:

• Silent mode (no --deliver): The agent receives the message and can act on it (e.g., update memory, run tools), but the response is NOT automatically sent to any chat. If the agent wants to send a message, it must explicitly use lettabot-message send.
• Delivery mode (--deliver channel:chatId): The agent's response is automatically delivered to the specified channel/chat after execution.

Message Format

When a cron job runs, the agent receives a message like:

[cron:cron-123abc Morning Briefing] Good morning! Review tasks for today.
Current time: 1/27/2026, 8:00:00 AM (America/Los_Angeles)

This tells the agent:

• The message came from a cron job (not a user)
• The job ID and name
• The current time

Cron Schedule Syntax

┌───────── minute (0-59)
│ ┌─────── hour (0-23)  
│ │ ┌───── day of month (1-31)
│ │ │ ┌─── month (1-12)
│ │ │ │ ┌─ day of week (0-6, Sun=0)
* * * * *

Examples

Daily morning check-in (delivered to Telegram):

lettabot-cron create \
  -n "Morning" \
  -s "0 8 * * *" \
  -m "Good morning! What's on today's agenda?" \
  -d telegram:123456789

Weekly review (delivered to Slack):

lettabot-cron create \
  -n "Weekly Review" \
  -s "0 17 * * 5" \
  -m "Friday wrap-up: What did we accomplish?" \
  -d slack:C1234567890

Background task (silent mode - agent acts but no auto-delivery):

lettabot-cron create \
  -n "Email Check" \
  -s "0 */2 * * *" \
  -m "Check for new emails and summarize anything important."

Notes

• Jobs schedule immediately when created (no restart needed)
• Use lettabot-cron list to see next run times and last run status
• Jobs persist in cron-jobs.json
• Logs written to cron-log.jsonl
• Without --deliver, the agent must use lettabot-message send to communicate results to users