Free Cron Job API — Schedule Tasks & Trigger Webhooks

Need to run tasks on a schedule without managing a crontab or a background worker? The Agent Scheduler API lets you create cron jobs, fixed-interval timers, and one-shot delayed tasks via REST. It triggers webhooks on schedule, tracks execution history, and supports pause/resume — all without setting up any infrastructure.

In this guide you'll learn how to create scheduled jobs, validate cron expressions, manage execution history, and build real-world automation workflows with the API.

Quick Start — Create a Cron Job

Get an API key (free), then create a cron job that triggers a webhook every 5 minutes:

Step 1: Get an API Key

curl -X POST https://agent-gateway-kappa.vercel.app/v1/agent-scheduler/api/keys/create

{
  "apiKey": "sc_abc123...",
  "credits": 100,
  "plan": "free"
}

Step 2: Create a Cron Schedule

curl -X POST https://agent-gateway-kappa.vercel.app/v1/agent-scheduler/api/schedules \
  -H "Authorization: Bearer sc_abc123..." \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Health Check",
    "type": "cron",
    "expression": "*/5 * * * *",
    "webhook": {
      "url": "https://your-app.com/api/health-check",
      "method": "POST",
      "headers": {"X-Source": "scheduler"},
      "body": {"check": "database"}
    },
    "timezone": "America/New_York"
  }'

# Response:
{
  "id": "sch_a1b2c3d4",
  "name": "Health Check",
  "type": "cron",
  "expression": "*/5 * * * *",
  "timezone": "America/New_York",
  "status": "active",
  "nextExecution": "2026-03-03T16:30:00.000Z",
  "created": "2026-03-03T16:27:42.123Z"
}

import requests

API_KEY = "sc_abc123..."
BASE = "https://agent-gateway-kappa.vercel.app/v1/agent-scheduler"

resp = requests.post(
    f"{BASE}/api/schedules",
    headers={"Authorization": f"Bearer {API_KEY}"},
    json={
        "name": "Health Check",
        "type": "cron",
        "expression": "*/5 * * * *",
        "webhook": {
            "url": "https://your-app.com/api/health-check",
            "method": "POST",
            "body": {"check": "database"}
        },
        "timezone": "America/New_York"
    }
)
schedule = resp.json()
print(f"Created: {schedule['id']}, next run: {schedule['nextExecution']}")

const API_KEY = "sc_abc123...";
const BASE = "https://agent-gateway-kappa.vercel.app/v1/agent-scheduler";

const resp = await fetch(`${BASE}/api/schedules`, {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${API_KEY}`,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    name: "Health Check",
    type: "cron",
    expression: "*/5 * * * *",
    webhook: {
      url: "https://your-app.com/api/health-check",
      method: "POST",
      body: { check: "database" }
    },
    timezone: "America/New_York"
  })
});
const schedule = await resp.json();
console.log(`Created: ${schedule.id}, next: ${schedule.nextExecution}`);

API Endpoints

Schedule Types

Cron Expression

Standard 5-field cron syntax. Runs at exact times matching the pattern:

# Every weekday at 9 AM ET
{
  "type": "cron",
  "expression": "0 9 * * 1-5",
  "timezone": "America/New_York"
}

# First day of every month at midnight
{
  "type": "cron",
  "expression": "0 0 1 * *"
}

# Every 15 minutes during business hours
{
  "type": "cron",
  "expression": "*/15 9-17 * * *"
}

Fixed Interval

Repeat at a fixed interval from the moment the schedule is created:

# Every 30 seconds
{
  "type": "interval",
  "interval": 30,
  "unit": "seconds"
}

# Every 2 hours
{
  "type": "interval",
  "interval": 2,
  "unit": "hours"
}

One-Shot Timer

Execute once after a delay — useful for deferred tasks:

# Execute once, 30 minutes from now
{
  "type": "once",
  "delay": 1800
}

# Execute once at a specific time
{
  "type": "once",
  "runAt": "2026-03-04T00:00:00Z"
}

Validate Cron Expressions

Not sure if your cron syntax is correct? Use the validator to check and preview next execution times:

curl -X POST https://agent-gateway-kappa.vercel.app/v1/agent-scheduler/api/cron/validate \
  -H "Content-Type: application/json" \
  -d '{"expression": "*/5 * * * *"}'

{
  "valid": true,
  "expression": "*/5 * * * *",
  "timezone": "UTC",
  "nextExecutions": [
    "2026-03-03T20:30:00.000Z",
    "2026-03-03T20:35:00.000Z",
    "2026-03-03T20:40:00.000Z",
    "2026-03-03T20:45:00.000Z",
    "2026-03-03T20:50:00.000Z"
  ]
}

Manage Schedules

Pause and Resume

# Pause during maintenance
curl -X POST https://agent-gateway-kappa.vercel.app/v1/agent-scheduler/api/schedules/sch_a1b2c3d4/pause \
  -H "Authorization: Bearer sc_abc123..."

# Resume when ready
curl -X POST https://agent-gateway-kappa.vercel.app/v1/agent-scheduler/api/schedules/sch_a1b2c3d4/resume \
  -H "Authorization: Bearer sc_abc123..."

Manual Trigger

# Fire the webhook right now (doesn't affect the regular schedule)
curl -X POST https://agent-gateway-kappa.vercel.app/v1/agent-scheduler/api/schedules/sch_a1b2c3d4/trigger \
  -H "Authorization: Bearer sc_abc123..."

View Execution History

curl https://agent-gateway-kappa.vercel.app/v1/agent-scheduler/api/schedules/sch_a1b2c3d4/executions \
  -H "Authorization: Bearer sc_abc123..."

{
  "executions": [
    {
      "id": "exec_001",
      "scheduledFor": "2026-03-03T16:30:00.000Z",
      "executedAt": "2026-03-03T16:30:00.412Z",
      "status": "success",
      "responseCode": 200,
      "duration_ms": 145
    },
    {
      "id": "exec_002",
      "scheduledFor": "2026-03-03T16:35:00.000Z",
      "executedAt": "2026-03-03T16:35:00.389Z",
      "status": "failed",
      "responseCode": 503,
      "error": "Service Unavailable",
      "duration_ms": 5012
    }
  ]
}

Real-World Use Cases

Comparison: Free Cron API vs Alternatives

Key advantage: Agent Scheduler is fully API-driven — no web dashboard required. Create, manage, and monitor schedules entirely through REST calls. Most alternatives are GUI-first tools that bolt on an API as an afterthought.

Common Cron Expressions

FAQ