Cronjob-Org Skill

Cronjob-Org Skill

Comprehensive assistance with the Cron-Job.org REST API for programmatically managing scheduled HTTP jobs. This skill provides guidance on creating, updating, deleting, and monitoring cron jobs through the official API.

When to Use This Skill

This skill should be triggered when:

• Creating automated HTTP requests on a schedule using Cron-Job.org
• Managing cron jobs programmatically through the REST API
• Implementing job monitoring and execution history tracking
• Setting up notifications for job failures or successes
• Working with API authentication and rate limits
• Debugging cron job executions or analyzing performance metrics
• Building integrations that require scheduled HTTP calls
• Configuring job schedules using timezone-aware cron expressions

Key Concepts

API Authentication

• API Keys: Generated in the Cron-Job.org Console under Settings
• Bearer Token: API keys are sent via the Authorization header
• IP Restrictions: Optional IP allowlisting for enhanced security
• Rate Limits: 100 requests/​day (default), 5,000 requests/​day (sustaining members)

Job Object

A Job represents a scheduled HTTP request with:

• URL: The endpoint to call
• Schedule: Cron expression with timezone support
• Settings: Timeout, HTTP method, headers, authentication
• State: Enabled/​disabled, execution status, history

Execution History

Each job execution creates a HistoryItem containing:

• Timing: Actual vs planned execution time, jitter, duration
• Response: HTTP status code, headers, body (if saveResponses enabled)
• Performance: DNS lookup, connection, SSL handshake, transfer times

Rate Limits

Different endpoints have different rate limits:

• Job List/​Details: 5 requests/​second
• Job Creation: 1 request/​second, 5 requests/​minute
• History: 5 requests/​second

Quick Reference

1. Authentication Setup

# Set your API key as a bearer token in the Authorization header
Authorization: Bearer YOUR_API_KEY_HERE

Notes:

• API keys are generated in the Console → Settings
• Treat API keys as secrets (like passwords)
• Enable IP restrictions whenever possible for security

2. List All Jobs (curl)

curl -X GET https://api.cron-job.org/​jobs \
  -H "Authorization: Bearer YOUR_API_KEY"

Response:

{
  "jobs": [
    {
      "jobId": 12345,
      "enabled": true,
      "title": "Daily Backup",
      "url": "https://example.com/​backup",
      "lastStatus": 200,
      "lastExecution": 1699920000,
      "nextExecution": 1700006400
    }
  ],
  "jobsPartialError": false
}

Rate Limit: 5 requests/​second

3. Create a New Job (Python)

import requests

API_KEY = "your_api_key_here"
headers = {
    "Authorization": f"Bearer {API_KEY}",
    "Content-Type": "application/​json"
}

job_data = {
    "job": {
        "url": "https://example.com/​api/​health-check",
        "enabled": True,
        "title": "Health Check",
        "saveResponses": True,
        "schedule": {
            "timezone": "America/​New_York",
            "hours": [-1],          # Every hour
            "mdays": [-1],          # Every day of month
            "minutes": [0],         # At minute 0
            "months": [-1],         # Every month
            "wdays": [-1]           # Every day of week
        }
    }
}

response = requests.post(
    "https://api.cron-job.org/​jobs",
    headers=headers,
    json=job_data
)

print(f"Created job ID: {response.json()['jobId']}")

Rate Limit: 1 request/​second, 5 requests/​minute

4. Update an Existing Job

import requests

API_KEY = "your_api_key_here"
JOB_ID = 12345

headers = {
    "Authorization": f"Bearer {API_KEY}",
    "Content-Type": "application/​json"
}

# Only include fields you want to change
update_data = {
    "job": {
        "enabled": False,  # Disable the job
        "title": "Updated Title"
    }
}

response = requests.patch(
    f"https://api.cron-job.org/​jobs/​{JOB_ID}",
    headers=headers,
    json=update_data
)

print("Job updated successfully" if response.status_code == 200 else "Update failed")

Rate Limit: 5 requests/​second

5. Job with HTTP Authentication

{
  "job": {
    "url": "https://api.example.com/​protected",
    "enabled": true,
    "title": "Protected Endpoint",
    "auth": {
      "enable": true,
      "user": "api_user",
      "password": "secret_password"
    }
  }
}

Notes:

• Uses HTTP Basic Authentication
• Credentials are stored securely by Cron-Job.org

6. Job with Custom Headers

{
  "job": {
    "url": "https://api.example.com/​webhook",
    "enabled": true,
    "title": "Webhook with Headers",
    "extendedData": {
      "headers": {
        "X-API-Key": "your-api-key",
        "Content-Type": "application/​json",
        "User-Agent": "MyCronJob/​1.0"
      },
      "body": "{\"event\": \"scheduled_check\"}"
    },
    "requestMethod": 1  // 0=GET, 1=POST, 2=PUT, 3=PATCH, 4=DELETE, etc.
  }
}

7. Job with Failure Notifications

{
  "job": {
    "url": "https://example.com/​critical-task",
    "enabled": true,
    "title": "Critical Task",
    "notifications": {
      "onFailure": true,
      "onSuccess": false,
      "onDisable": true
    }
  }
}

Notification Options:

• onFailure: Notify after job fails (set onFailureMinutes for threshold)
• onSuccess: Notify when job succeeds after previous failure
• onDisable: Notify when job is automatically disabled

8. Get Job Execution History

import requests

API_KEY = "your_api_key_here"
JOB_ID = 12345

headers = {"Authorization": f"Bearer {API_KEY}"}

response = requests.get(
    f"https://api.cron-job.org/​jobs/​{JOB_ID}/​history",
    headers=headers
)

data = response.json()
print(f"Last {len(data['history'])} executions:")
for item in data['history']:
    print(f"  {item['date']}: Status {item['httpStatus']} ({item['duration']}ms)")

print(f"\nNext executions: {data['predictions']}")

Rate Limit: 5 requests/​second

9. Schedule Examples

Every day at 2:30 AM EST:

{
  "schedule": {
    "timezone": "America/​New_York",
    "hours": [2],
    "mdays": [-1],
    "minutes": [30],
    "months": [-1],
    "wdays": [-1]
  }
}

Every Monday and Friday at 9 AM UTC:

{
  "schedule": {
    "timezone": "UTC",
    "hours": [9],
    "mdays": [-1],
    "minutes": [0],
    "months": [-1],
    "wdays": [1, 5]  // 0=Sunday, 1=Monday, ..., 6=Saturday
  }
}

Every 15 minutes:

{
  "schedule": {
    "timezone": "UTC",
    "hours": [-1],
    "mdays": [-1],
    "minutes": [0, 15, 30, 45],
    "months": [-1],
    "wdays": [-1]
  }
}

10. Delete a Job

import requests

API_KEY = "your_api_key_here"
JOB_ID = 12345

headers = {"Authorization": f"Bearer {API_KEY}"}

response = requests.delete(
    f"https://api.cron-job.org/​jobs/​{JOB_ID}",
    headers=headers
)

print("Job deleted" if response.status_code == 200 else "Delete failed")

Rate Limit: 5 requests/​second

Reference Files

This skill includes comprehensive documentation in references/:

• api.md - Complete REST API reference including:
  • Authentication and security
  • Rate limits and quotas
  • All API endpoints (jobs, history)
  • Request/​response formats
  • Object schemas (Job, DetailedJob, JobSchedule, HistoryItem, etc.)
  • HTTP status codes and error handling
  • Timing statistics and performance metrics

Use the reference file for:

• Detailed object schema documentation
• Complete list of request/​response fields
• Advanced configuration options
• Troubleshooting API errors

Working with This Skill

For Beginners

1. Start by reading the API authentication section in references/​api.md
2. Generate an API key in the Cron-Job.org Console
3. Use the Quick Reference examples above to:
   • List your existing jobs
   • Create a simple job with a basic schedule
   • View execution history
4. Test with curl or Python before building integrations

For Intermediate Users

Focus on:

• Custom headers and authentication for API integrations
• Notification settings for failure alerting
• Schedule optimization using timezone-aware cron expressions
• Execution history analysis for monitoring job performance
• Rate limit management for high-volume applications

For Advanced Users

Explore:

• Batch job management with proper rate limit handling
• Performance optimization using timing statistics from HistoryItem
• Error handling strategies based on HTTP status codes
• IP allowlisting for production security
• Sustaining membership for higher API quotas (5,000 requests/​day)

Navigation Tips

• Use references/​api.md for complete endpoint documentation
• Check HTTP status codes section for error troubleshooting
• Review object schemas for all available configuration fields
• Reference the schedule examples for common cron patterns

Common Patterns

Pattern 1: Health Check Monitoring

Create a job that pings your service every 5 minutes and notifies on failure:

job = {
    "url": "https://myapp.com/​health",
    "enabled": True,
    "title": "App Health Check",
    "saveResponses": False,
    "schedule": {
        "timezone": "UTC",
        "hours": [-1],
        "mdays": [-1],
        "minutes": [0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55],
        "months": [-1],
        "wdays": [-1]
    },
    "notifications": {
        "onFailure": True,
        "onSuccess": True,
        "onDisable": True
    }
}

Pattern 2: Daily Data Sync

Trigger a webhook at 3 AM daily with custom headers:

job = {
    "url": "https://api.myapp.com/​sync",
    "enabled": True,
    "title": "Daily Data Sync",
    "requestMethod": 1,  # POST
    "extendedData": {
        "headers": {
            "X-Sync-Token": "secret",
            "Content-Type": "application/​json"
        },
        "body": '{"action": "daily_sync"}'
    },
    "schedule": {
        "timezone": "America/​Los_Angeles",
        "hours": [3],
        "mdays": [-1],
        "minutes": [0],
        "months": [-1],
        "wdays": [-1]
    }
}

Pattern 3: Weekday Business Hours Job

Run a job every weekday at 9 AM and 5 PM:

job = {
    "url": "https://example.com/​business-task",
    "enabled": True,
    "title": "Business Hours Task",
    "schedule": {
        "timezone": "America/​New_York",
        "hours": [9, 17],
        "mdays": [-1],
        "minutes": [0],
        "months": [-1],
        "wdays": [1, 2, 3, 4, 5]  # Monday-Friday
    }
}

HTTP Status Codes

Important Limits

• Daily Quota: 100 requests/​day (default), 5,000 requests/​day (sustaining members)
• Job Creation: 1 request/​second, 5 requests/​minute
• Other Endpoints: 5 requests/​second
• Job Timeout: Configurable per job (default system timeout applies)
• Response Storage: Enable saveResponses to store headers/​body in history

Security Best Practices

1. Protect API Keys: Treat them like passwords, never commit to version control
2. Enable IP Restrictions: Limit API access to specific IP addresses
3. Use HTTPS: All API communication is HTTPS-only
4. Rotate Keys: Periodically regenerate API keys
5. Monitor Usage: Track API request counts to avoid quota exhaustion

Resources

Official Documentation

• REST API Docs: https://docs.cron-job.org/rest-api.html
• Console: https://console.cron-job.org/

Supported Timezones

See the official documentation for a complete list of supported timezone values (e.g., "UTC", "America/​New_York", "Europe/​London").

Example Use Cases

• API Health Checks: Monitor service availability
• Data Synchronization: Trigger scheduled data imports/​exports
• Report Generation: Generate and send periodic reports
• Cache Warming: Pre-load caches before peak traffic
• Webhook Delivery: Send scheduled webhook notifications
• Backup Triggers: Initiate automated backup processes

Troubleshooting

401 Unauthorized

• Verify API key is correct
• Check Authorization header format: Authorization: Bearer YOUR_KEY
• Ensure API key hasn't been revoked

403 Forbidden

• Check if IP restrictions are enabled
• Verify your IP address is allowlisted

429 Too Many Requests

• Review rate limits for specific endpoint
• Implement exponential backoff
• Consider sustaining membership for higher limits

Job Not Executing

• Verify job is enabled
• Check schedule configuration
• Review nextExecution timestamp
• Check if job has been auto-disabled due to failures

Missing Response Data in History

• Ensure saveResponses is set to true
• Use the detailed history item endpoint for headers/​body

Notes

• All timestamps are Unix timestamps in seconds
• Schedule uses arrays where [-1] means "all values" (every hour, every day, etc.)
• Job execution times may have jitter (scheduling delay) - check HistoryItem.jitter
• Failed jobs may be automatically disabled based on notification settings
• Execution history is limited; use the API to retrieve recent items

Updating

This skill was generated from official Cron-Job.org documentation. For the latest API changes:

1. Visit https://docs.cron-job.org/rest-api.html
2. Check for new endpoints or schema changes
3. Update your integration code accordingly