🎯 Mục tiêu

• Hiểu các loại triggers
• Setup Schedule triggers
• Tạo Webhook endpoints
• Sử dụng App triggers (Gmail, Slack, etc.)

1. Trigger Overview

1.1 Trigger Categories

1.2 Khi nào dùng trigger nào?

1📅 Schedule: Báo cáo hàng ngày, backup data, sync data
2🔗 Webhook: Form submit, payment notification, CI/CD
3📧 App Trigger: New email → process, new Slack message → respond
4🖱️ Manual: Testing, one-time tasks
5⚠️ Error: Alert khi workflow fails

2. Schedule Trigger

2.1 Cron Expressions

1Cron format: [second] [minute] [hour] [day-of-month] [month] [day-of-week]
2 
3Ví dụ:
40 9 * * 1-5    → Thứ 2-6, 9:00 AM
50 0 * * *      → Mỗi ngày, 12:00 AM (midnight)
6*/30 * * * *   → Mỗi 30 phút
70 8 1 * *      → Ngày 1 mỗi tháng, 8:00 AM
80 9,18 * * *   → 9 AM và 6 PM mỗi ngày

2.2 Schedule Node Setup

1. Add node Schedule Trigger
2. Chọn trigger mode:
   • Every X minutes/hours — Đơn giản
   • Cron Expression — Linh hoạt
   • Specific dates — Ngày cụ thể

2.3 Use Cases

Daily Sales Report:

1Schedule (9 AM) → Google Sheets (get data) → AI Summarize → Slack (post)

Weekly Backup:

1Schedule (Sunday 2 AM) → Database Query → Google Drive (upload)

Hourly Monitoring:

1Schedule (every 1h) → HTTP Request (health check) → IF failed → Email alert

3. Webhook Trigger

3.1 What is a Webhook?

1Webhook = URL mà external services gọi khi event xảy ra
2 
3Ví dụ:
4- Stripe gọi webhook khi payment thành công
5- GitHub gọi webhook khi có push
6- Form submit gọi webhook với form data

3.2 Setup Webhook

1. Add node Webhook
2. n8n tạo URL: https://your-n8n.com/webhook/abc123
3. Chọn HTTP Method: GET, POST, PUT, DELETE
4. Copy URL → paste vào external service

3.3 Webhook Configuration

3.4 Example: Contact Form

1Webhook (POST /contact) 
2→ Validate data (IF)
3→ Google Sheets (save)
4→ Email notification (send)
5→ Respond "Thank you!"

Webhook receives:

1{
2  "name": "Nguyễn Văn A",
3  "email": "a@email.com",
4  "message": "Tôi muốn tư vấn sản phẩm XYZ"
5}

3.5 Test Webhooks

1# Test locally with curl
2curl -X POST http://localhost:5678/webhook/abc123 \
3  -H "Content-Type: application/json" \
4  -d '{"name": "Test", "email": "test@email.com"}'
5 
6# Online testing: webhook.site, requestbin.com

3.6 Security

1⚠️ Webhook URL là public — ai cũng có thể gọi!
2 
3Bảo mật:
41. Basic Auth: Username + Password
52. Header Auth: Secret token trong header
63. IP Whitelist: Chỉ cho phép IPs cụ thể
74. HMAC Validation: Verify request signature

4. App Triggers

4.1 Gmail Trigger

1Trigger: New email received
2Filters: From specific sender, subject contains "urgent"
3Output: sender, subject, body, attachments

Setup:

1. Add Gmail Trigger node
2. Connect Google account
3. Set filters (optional)
4. Set poll interval (every 1 min - 1 hour)

4.2 Slack Trigger

1Trigger: New message in channel
2Output: message text, user, channel, timestamp

4.3 Google Sheets Trigger

1Trigger: New row added / Row updated
2Output: Row data as JSON

4.4 Common App Trigger Patterns

5. Error Trigger

5.1 Setup Error Monitoring

1Error Trigger → Format error details → Send alert

Error Trigger fires when ANY workflow in your n8n instance fails.

5.2 Error Data

1{
2  "execution": {
3    "id": "123",
4    "url": "https://n8n.example.com/execution/123",
5    "error": {
6      "message": "Cannot read property 'email' of undefined",
7      "node": "Send Email"
8    }
9  },
10  "workflow": {
11    "id": "45",
12    "name": "Daily Report"
13  }
14}

5.3 Alert Workflow

1Error Trigger 
2→ Format message: "❌ Workflow '{workflow.name}' failed: {error.message}"
3→ Slack (post to #alerts)
4→ Email (send to admin)

6. Advanced: Combining Triggers

6.1 Multi-Trigger Workflow

Một workflow chỉ có 1 trigger, nhưng bạn có thể:

1Approach 1: Webhook gọi workflow khác
2Webhook → Execute Workflow (trigger Daily Report)
3 
4Approach 2: Merge workflows
5Workflow A (Schedule) → Webhook to Workflow C
6Workflow B (Slack trigger) → Webhook to Workflow C
7Workflow C (Webhook) → Process → Output

6.2 Trigger + Filter

1Gmail Trigger (all emails)
2→ IF (subject contains "invoice")
3  → TRUE: Process invoice
4  → FALSE: Archive

7. Hands-on Lab

Lab 1: Morning Briefing

Tạo workflow chạy 8 AM hàng ngày:

1. Schedule Trigger (8:00 AM, Mon-Fri)
2. HTTP Request — Get weather forecast
3. Google Calendar — Get today's events
4. AI — Summarize into briefing
5. Slack — Post to personal channel

Lab 2: Lead Capture Webhook

1. Webhook (POST /new-lead)
2. Validate — Check required fields
3. Google Sheets — Save lead data
4. Email — Send confirmation to lead
5. Slack — Notify sales team

Lab 3: Error Alert System

1. Error Trigger
2. Format error details
3. Slack — Post to #n8n-alerts
4. Email — Send to admin (if critical)

📝 Quiz

1. Webhook trigger khác Schedule trigger ở điểm nào?

   • Webhook chạy khi nhận HTTP request, Schedule chạy theo thời gian
   • Webhook miễn phí, Schedule trả phí
   • Webhook nhanh hơn
   • Không khác nhau

2. Cron expression 0 9 * * 1-5 nghĩa là?

   • Mỗi 9 phút
   • 9 AM thứ 2 đến thứ 6
   • Ngày 9 hàng tháng
   • 9 PM mỗi ngày

3. Error Trigger fires khi?

   • User nhấn button
   • Scheduled time
   • Bất kỳ workflow nào fail
   • New email

🎯 Key Takeaways

1. Schedule — Cho recurring tasks (daily reports, backups)
2. Webhook — Cho external events (form submissions, payments)
3. App Triggers — Cho app-specific events (new email, Slack message)
4. Error Trigger — Giám sát tất cả workflows
5. Security — Luôn bảo mật webhook URLs