Cron Triggers Configuration

wrangler.jsonc

{
  "$schema": "./node_modules/wrangler/config-schema.json",
  "name": "my-cron-worker",
  "main": "src/index.ts",
  "compatibility_date": "2025-01-01", // Use current date for new projects
  
  "triggers": {
    "crons": [
      "*/5 * * * *",     // Every 5 minutes
      "0 */2 * * *",     // Every 2 hours
      "0 9 * * MON-FRI", // Weekdays at 9am UTC
      "0 2 1 * *"        // Monthly on 1st at 2am UTC
    ]
  }
}

Green Compute (Beta)

Schedule crons during low-carbon periods for carbon-aware execution:

{
  "name": "eco-cron-worker",
  "triggers": {
    "crons": ["0 2 * * *"]
  },
  "placement": {
    "mode": "smart"  // Runs during low-carbon periods
  }
}

Modes:

"smart" - Carbon-aware scheduling (may delay up to 24h for optimal window)
Default (no placement config) - Standard scheduling (no delay)

How it works:

Cloudflare delays execution until grid carbon intensity is lower
Maximum delay: 24 hours from scheduled time
Ideal for batch jobs with flexible timing requirements

Use cases:

Nightly data processing and ETL pipelines
Weekly/monthly report generation
Database backups and maintenance
Analytics aggregation
ML model training

Not suitable for:

Time-sensitive operations (SLA requirements)
User-facing features requiring immediate execution
Real-time monitoring and alerting
Compliance tasks with strict time windows

Environment-Specific Schedules

{
  "name": "my-cron-worker",
  "triggers": {
    "crons": ["0 */6 * * *"]  // Prod: every 6 hours
  },
  "env": {
    "staging": {
      "triggers": {
        "crons": ["*/15 * * * *"]  // Staging: every 15min
      }
    },
    "dev": {
      "triggers": {
        "crons": ["*/5 * * * *"]  // Dev: every 5min
      }
    }
  }
}

Schedule Format

Structure: minute hour day-of-month month day-of-week

Special chars: * (any), , (list), - (range), / (step), L (last), W (weekday), # (nth)

Managing Triggers

Remove all: "triggers": { "crons": [] }
Preserve existing: Omit "triggers" field entirely

Deployment

# Deploy with config crons
npx wrangler deploy

# Deploy specific environment
npx wrangler deploy --env production

# View deployments
npx wrangler deployments list

⚠️ Changes take up to 15 minutes to propagate globally

API Management

Get triggers:

curl "https://api.cloudflare.com/client/v4/accounts/{account_id}/workers/scripts/{script_name}/schedules" \
  -H "Authorization: Bearer {api_token}"

Update triggers:

curl -X PUT "https://api.cloudflare.com/client/v4/accounts/{account_id}/workers/scripts/{script_name}/schedules" \
  -H "Authorization: Bearer {api_token}" \
  -H "Content-Type: application/json" \
  -d '{"crons": ["*/5 * * * *", "0 2 * * *"]}'

Delete all:

curl -X PUT "https://api.cloudflare.com/client/v4/accounts/{account_id}/workers/scripts/{script_name}/schedules" \
  -H "Authorization: Bearer {api_token}" \
  -H "Content-Type: application/json" \
  -d '{"crons": []}'

Combining Multiple Workers

For complex schedules, use multiple workers:

// worker-frequent.jsonc
{
  "name": "data-sync-frequent",
  "triggers": { "crons": ["*/5 * * * *"] }
}

// worker-daily.jsonc
{
  "name": "reports-daily",
  "triggers": { "crons": ["0 2 * * *"] },
  "placement": { "mode": "smart" }
}

// worker-weekly.jsonc
{
  "name": "cleanup-weekly",
  "triggers": { "crons": ["0 3 * * SUN"] }
}

Benefits:

Separate CPU limits per worker
Independent error isolation
Different Green Compute policies
Easier to maintain and debug

Validation

Test cron syntax:

crontab.guru - Interactive validator
Wrangler validates on deploy but won't catch logic errors

Common mistakes:

0 0 * * * runs daily at midnight UTC, not your local timezone
*/60 * * * * is invalid (use 0 * * * * for hourly)
0 2 31 * * only runs on months with 31 days

/cloudflare-deploy

referencescron-triggersconfiguration.md