Cron Tools

PRX fournit neuf outils pour l'automatisation de taches basees sur le temps, couvrant la cron job management and the advanced Xin scheduling engine. These tools let l'agent create scheduled tasks, inspect job history, trigger manual runs, and orchestrate background operations on recurring schedules.

Les outils cron sont divises en deux systemes: le sous-systeme cron pour les taches planifiees standard utilisant des expressions cron, and the Xin engine for advanced task scheduling with dependency chains, conditional execution, and integration avec le self-evolution pipeline.

Toutes les taches cron et les outils de planification sont enregistres dans le all_tools() registry and sont disponibles lorsqu'ever le daemon is running.

Configuration

Cron System

[cron]
enabled = true
timezone = "UTC"           # Timezone for cron expressions

# Define built-in scheduled tasks
[[cron.tasks]]
name = "daily-report"
schedule = "0 9 * * *"     # Every day at 09:00 UTC
action = "agent"
prompt = "Generate a daily summary report and send it to the user."

[[cron.tasks]]
name = "memory-cleanup"
schedule = "0 3 * * *"     # Every day at 03:00 UTC
action = "agent"
prompt = "Run memory hygiene: archive old daily entries and compact core memories."

[[cron.tasks]]
name = "repo-check"
schedule = "*/30 * * * *"  # Every 30 minutes
action = "shell"
command = "cd /home/user/project && git fetch --all"

Xin Engine

[xin]
enabled = true
interval_minutes = 5            # Tick interval in minutes (minimum 1)
max_concurrent = 4              # Maximum concurrent task executions per tick
max_tasks = 128                 # Maximum total tasks in the store
stale_timeout_minutes = 60      # Minutes before a running task is marked stale
builtin_tasks = true            # Auto-register built-in system tasks
evolution_integration = false   # Let Xin manage evolution/fitness scheduling

Reference des outils

cron_add

Adds un nouveau cron job avec un cron expression, command or prompt, and optional description.

{
  "name": "cron_add",
  "arguments": {
    "name": "backup-workspace",
    "schedule": "0 2 * * *",
    "action": "shell",
    "command": "tar czf /tmp/workspace-$(date +%Y%m%d).tar.gz /home/user/workspace",
    "description": "Daily workspace backup at 2 AM"
  }
}

Parametre	Type	Requis	Defaut	Description
name	string	Oui	--	Unique name pour le cron job
schedule	string	Oui	--	Cron expression (5-field: minute hour day month weekday)
action	string	Oui	--	Action type: "shell" (run command) or "agent" (run agent prompt)
command	string	Conditional	--	Shell command (required when action = "shell")
prompt	string	Conditional	--	Agent prompt (required when action = "agent")
description	string	Non	--	Human-readable description

cron_list

Lists all registered cron jobs with their schedules, status, and next run time.

{
  "name": "cron_list",
  "arguments": {}
}

Non parameters required. Retours a table of all cron jobs.

cron_remove

Removes a cron job by its name or ID.

{
  "name": "cron_remove",
  "arguments": {
    "name": "backup-workspace"
  }
}

Parametre	Type	Requis	Defaut	Description
name	string	Oui	--	Name or ID of the cron job to remove

cron_update

Updates an existing cron job's schedule, command, or settings.

{
  "name": "cron_update",
  "arguments": {
    "name": "backup-workspace",
    "schedule": "0 4 * * *",
    "description": "Daily workspace backup at 4 AM (shifted)"
  }
}

Parametre	Type	Requis	Defaut	Description
name	string	Oui	--	Name of the cron job to update
schedule	string	Non	--	New cron expression
command	string	Non	--	New shell command
prompt	string	Non	--	New agent prompt
description	string	Non	--	New description

cron_run

Manually triggers a cron job immediately, outside its normal schedule.

{
  "name": "cron_run",
  "arguments": {
    "name": "daily-report"
  }
}

Parametre	Type	Requis	Defaut	Description
name	string	Oui	--	Name of the cron job to trigger

cron_runs

Affiche l'historique d'execution et les journaux des executions de taches cron. Affiche les executions passees avec horodatages, statut et sortie.

{
  "name": "cron_runs",
  "arguments": {
    "name": "daily-report",
    "limit": 10
  }
}

Parametre	Type	Requis	Defaut	Description
name	string	Non	--	Filter by job name. If omitted, shows all recent runs.
limit	integer	Non	20	Maximum number of history entries to retour

schedule

Planifie une tache ponctuelle ou recurrente avec des expressions temporelles en langage naturel. C'est un outil de niveau superieul interface than raw cron expressions.

{
  "name": "schedule",
  "arguments": {
    "when": "in 30 minutes",
    "action": "agent",
    "prompt": "Check if the deployment completed and report the status."
  }
}

Parametre	Type	Requis	Defaut	Description
when	string	Oui	--	Natural language time expression (e.g., "in 30 minutes", "tomorrow at 9am", "every Monday at 10:00")
action	string	Oui	--	Action type: "shell" or "agent"
command	string	Conditional	--	Shell command (for "shell" action)
prompt	string	Conditional	--	Agent prompt (for "agent" action)

cron (Legacy)

Legacy cron entry point for backward compatibility. Routes vers le appropriate cron tool based sur le action argument.

{
  "name": "cron",
  "arguments": {
    "action": "list"
  }
}

xin

The Xin scheduling engine for advanced task automation with dependency chains and conditional execution.

{
  "name": "xin",
  "arguments": {
    "action": "status"
  }
}

Parametre	Type	Requis	Defaut	Description
action	string	Oui	--	Action: "status", "tasks", "run", "pause", "resume"

Cron Expression Format

PRX utilise standard 5-field cron expressions:

┌───────────── minute (0-59)
│ ┌───────────── hour (0-23)
│ │ ┌───────────── day of month (1-31)
│ │ │ ┌───────────── month (1-12)
│ │ │ │ ┌───────────── day of week (0-7, 0 and 7 = Sunday)
│ │ │ │ │
* * * * *

Examples:

Expression	Description
0 9 * * *	Every day at 9:00 AM
*/15 * * * *	Every 15 minutes
0 9 * * 1-5	Weekdays at 9:00 AM
0 0 1 * *	First day of every month at midnight
30 8,12,18 * * *	At 8:30, 12:30, and 18:30 daily

Xin Engine

The Xin engine is an advanced task scheduler that goes beyond simple cron timing:

• Dependency chains: Tasks can depend sur le successful completion of other tasks
• Conditional execution: Tasks run only when specified conditions are met
• Built-in tasks: System maintenance tasks (heartbeat, memory hygiene, log rotation) are auto-registered when builtin_tasks = true
• Evolution integration: When evolution_integration = true, Xin manages the self-evolution and fitness check schedule
• Stale detection: Tasks running longer than stale_timeout_minutes are marked as stale and peut etre cleaned up
• Concurrent execution: Multiple tasks can run in parallel, limited by max_concurrent

Utilisation

CLI Cron Management

# List all cron jobs
prx cron list

# Add a new cron job
prx cron add --name "check-updates" --schedule "0 */6 * * *" --action agent --prompt "Check for package updates"

# Manually trigger a job
prx cron run daily-report

# View run history
prx cron runs --name daily-report --limit 5

# Remove a job
prx cron remove check-updates

Xin Status

# Check Xin engine status
prx xin status

# List all Xin tasks
prx xin tasks

Securite

Shell Command Sandboxing

Cron jobs with action = "shell" execute via le same sandbox comme le shell tool. The configured sandbox backend (Landlock, Firejail, Bubblewrap, Docker) applies to scheduled commands.

Agent Prompt Safety

Cron jobs with action = "agent" spawn un nouveau session d'agent avec le configured prompt. L'session d'agent herite de le daemon's security policies, tool restrictions, and resource limits.

Moteur de politiques

Les outils cron sont gouvernes par le moteur de politiques de securite:

[security.tool_policy.groups]
automation = "allow"

[security.tool_policy.tools]
cron_add = "supervised"    # Require approval to add new jobs
cron_remove = "supervised" # Require approval to remove jobs
cron_run = "allow"         # Allow manual triggers

Journalisation d'audit

Toutes les taches cron operations sont enregistres dans le journal d'audit: job creation, modification, deletion, manual triggers, and execution results.

Limitees de ressources

Scheduled tasks share le daemon's resource limits. The max_concurrent setting in the Xin engine empeche epuisement des ressources from too many simultaneous tasks.

Voir aussi

• Cron System -- architecture and built-in tasks
• Cron Heartbeat -- health monitoring
• Cron Tasks -- built-in maintenance tasks
• Self-Evolution -- Xin evolution integration
• Shell Execution -- sandbox for shell-based cron jobs
• Configuration Reference -- [cron] and [xin] settings
• Tools Overview -- tous les outils et systeme de registre