One-Off Cron Jobs Sometimes you need to schedule a task to run just once at a specific time in the future. While A1Cron is primarily designed for recurring schedules, you can achieve one-off execution using a simple workaround with our existing scheduling options.
This is a temporary workaround. We’re developing enhanced features that will allow AI agents and applications to dynamically schedule one-time tasks more elegantly. Stay tuned for updates!
Why One-Off Jobs? One-off cron jobs are useful for:
Scheduled reminders : Send a reminder email at a specific future timeDelayed processing : Process data after a waiting periodTime-sensitive operations : Execute tasks at precise momentsEvent-driven scheduling : Schedule follow-ups based on user actionsAI agent tasks : Allow AI systems to schedule future actions dynamically
Method 1: Using End Occurrences The cleanest approach is to create a cron job that ends after exactly one execution.
How It Works Set end_type to "after" and end_occurrences to 1. The job will:
Wait until the scheduled time
Execute once
Automatically deactivate
Example: Schedule a Task for Tomorrow at 2:30 PM curl -X POST https://api.a1base.com/v1/cron-jobs/{accountId}/create \ -H "X-API-Key: your-api-key" \ -H "X-API-Secret: your-api-secret" \ -H "Content-Type: application/json" \ -d '{ "name": "Send Follow-up Email", "description": "One-time follow-up email to customer", "endpoint_url": "https://api.example.com/send-followup", "method": "POST", "headers": { "Content-Type": "application/json" }, "body": "{\"customer_id\": \"12345\", \"template\": \"followup_24h\"}", "timezone": "America/New_York", "schedule_config": { "repeat_type": "days", "repeat_every": 1, "time": "14:30", "end_type": "after", "end_occurrences": 1 }, "tags": ["one-off", "followup", "customer-12345"], "is_active": true }'
Method 2: Using End Date Alternatively, set an end date shortly after the desired execution time.
How It Works Set end_type to "on" with an end_date just after your target time. This ensures:
The job runs at the scheduled time
The schedule expires immediately after
Example: Schedule for a Specific Date and Time { "name" : "Holiday Sale Announcement" , "description" : "Send holiday sale email on Dec 25 at 9 AM" , "endpoint_url" : "https://api.example.com/send-announcement" , "method" : "POST" , "timezone" : "America/New_York" , "schedule_config" : { "repeat_type" : "days" , "repeat_every" : 1 , "time" : "09:00" , "end_type" : "on" , "end_date" : "2024-12-25T09:01:00-05:00" }, "tags" : [ "one-off" , "holiday" , "announcement" ] } When using the end date method, ensure the end_date is at least 1 minute after your scheduled time to account for any execution delays.
Practical Examples 1. Delayed Task Execution Schedule a task to run in 2 hours:
const scheduleDelayedTask = async ( delayHours = 2 ) => { const now = new Date (); const runTime = new Date ( now . getTime () + ( delayHours * 60 * 60 * 1000 )); const timeStr = ` ${ runTime . getHours (). toString (). padStart ( 2 , '0' ) } : ${ runTime . getMinutes (). toString (). padStart ( 2 , '0' ) } ` ; const response = await createCronJob ({ name: `Delayed Task - ${ now . toISOString () } ` , endpoint_url: "https://api.example.com/process-delayed" , schedule_config: { repeat_type: "days" , repeat_every: 1 , time: timeStr , end_type: "after" , end_occurrences: 1 } }); return response . data ; }; 2. AI Agent Scheduling Allow an AI agent to schedule a follow-up action:
def ai_schedule_followup ( user_id , action , delay_minutes ): """ AI agent schedules a one-time follow-up action """ run_time = datetime.now() + timedelta( minutes = delay_minutes) time_str = run_time.strftime( "%H:%M" ) cron_data = { "name" : f "AI Follow-up: { action } " , "description" : f "AI-scheduled task for user { user_id } " , "endpoint_url" : "https://api.example.com/ai/execute-action" , "method" : "POST" , "body" : json.dumps({ "user_id" : user_id, "action" : action, "scheduled_by" : "ai_agent" }), "timezone" : "UTC" , "schedule_config" : { "repeat_type" : "days" , "repeat_every" : 1 , "time" : time_str, "end_type" : "after" , "end_occurrences" : 1 }, "callbacks" : { "success_url" : "https://api.example.com/ai/action-completed" , "failure_url" : "https://api.example.com/ai/action-failed" }, "tags" : [ "ai-scheduled" , "one-off" , f "user- { user_id } " ] } # Create the one-off cron job return create_cron_job(cron_data) 3. Event-Driven Scheduling Schedule a task based on user events:
// When user signs up, schedule a welcome email for 24 hours later app . post ( '/user/signup' , async ( req , res ) => { const { userId , email } = req . body ; // Create user account await createUser ({ userId , email }); // Schedule welcome follow-up for tomorrow const tomorrow = new Date (); tomorrow . setDate ( tomorrow . getDate () + 1 ); const timeStr = "10:00" ; // 10 AM in user's timezone await scheduleOneOffCron ({ name: `Welcome Email - ${ userId } ` , endpoint_url: "https://api.example.com/emails/send-welcome" , method: "POST" , body: JSON . stringify ({ userId , email }), timezone: getUserTimezone ( userId ), schedule_config: { repeat_type: "days" , repeat_every: 1 , time: timeStr , end_type: "after" , end_occurrences: 1 }, tags: [ "welcome" , "one-off" , `user- ${ userId } ` ] }); res . json ({ message: "User created and welcome email scheduled" }); }); Best Practices for One-Off Jobs
Include timestamps or unique identifiers in job names to distinguish one-off tasks: { "name" : "Follow-up Email - User 12345 - 2024-01-25" }
Use tags to identify and manage one-off jobs: { "tags" : [ "one-off" , "temporary" , "user-12345" , "2024-01-25" ] }
Consider deleting completed one-off jobs to keep your job list clean: // In your success webhook handler app . post ( '/webhooks/cron-success' , async ( req , res ) => { const { cron_job_id , cron_job_name } = req . body ; if ( cron_job_name . includes ( 'one-off' )) { // Delete the completed one-off job await deleteCronJob ( cron_job_id ); } });
Set up webhook callbacks to confirm one-off tasks complete successfully: { "callbacks" : { "success_url" : "https://api.example.com/one-off-completed" , "failure_url" : "https://api.example.com/one-off-failed" } } Limitations and Considerations
Minimum Scheduling Time : Jobs can only be scheduled for future times, not immediate executionTimezone Awareness : Ensure you’re using the correct timezone for your one-off executionNo Second Precision : Cron jobs run at minute precision (HH:MM), not exact secondsCleanup Required : One-off jobs remain in your job list after execution unless manually deleted
Future Improvements We’re actively developing enhanced features for one-off scheduling:
Native one-off job type : Direct support without workaroundsDynamic scheduling API : Allow AI agents to schedule tasks programmaticallyImmediate execution : Option to run tasks with minimal delayBatch one-off scheduling : Create multiple one-off tasks in a single requestAuto-cleanup : Automatic removal of completed one-off jobs These improvements will make A1Cron even more powerful for AI agents and dynamic applications. Summary While A1Cron is designed for recurring schedules, you can effectively create one-off jobs using:
End occurrences method : Set end_occurrences: 1 for clean one-time executionEnd date method : Set an end date shortly after the scheduled time
Both methods work reliably for scheduling tasks that need to run exactly once at a future time. Choose the method that best fits your use case and remember to tag your one-off jobs appropriately for easy management.
For immediate task execution, consider using the manual trigger feature instead of scheduling a one-off job. 
