n8n-nodes-excel-api

An n8n community node for accessing Excel files via API with concurrent safety protection. Perfect for scenarios where multiple users simultaneously access the same Excel file through n8n workflows.

📖 中文文檔 | English Documentation

🎯 Why This Node?

The Problem

When working with Excel files directly in n8n:

• ❌ Multiple workflows accessing the same file cause file corruption
• ❌ Concurrent writes lead to data overwrite and loss
• ❌ No file locking mechanism
• ❌ Difficult to handle simultaneous webhook form submissions

The Solution

This node works with Excel API Server to provide:

• ✅ File Locking - Automatically queue concurrent requests
• ✅ Data Integrity - No data loss or corruption
• ✅ Multi-User Support - Perfect for multi-user HTML form submissions
• ✅ Google Sheets-like Interface - Familiar operations in n8n

📦 Installation

Method 1: npm (Recommended)

npm install n8n-nodes-excel-api

Method 2: Manual Installation

# 1. Clone repository
git clone https://gitlab.com/hueyanchen-group/n8n-nodes-excel-api.git
cd n8n-nodes-excel-api

# 2. Install dependencies
npm install

# 3. Build
npm run build

# 4. Link to n8n
npm link
cd ~/.n8n
npm link n8n-nodes-excel-api

# 5. Restart n8n
n8n start

Method 3: Community Package (After Publication)

In n8n:

1. Go to Settings → Community Nodes
2. Click Install
3. Enter: n8n-nodes-excel-api
4. Click Install

🚀 Prerequisites

You must run Excel API Server first!

Install and start Excel API Server:

# Quick start with Docker
docker run -d \
  -p 8000:8000 \
  -v $(pwd)/data:/app/data \
  -e API_TOKEN=your-secret-token \
  yourusername/excel-api-server

See Excel API Server Documentation for details.

🔧 Configuration

1. Set Up Credentials

In n8n:

1. Go to Credentials → New
2. Search for "Excel API"
3. Fill in:
   • API URL: http://localhost:8000 (Your API server address)
   • API Token: your-secret-token (From Excel API Server)
4. Click Save

2. Add Node to Workflow

1. Create or open a workflow
2. Click Add Node
3. Search for "Excel API"
4. Select the node
5. Choose your credential
6. Configure operation

📚 Operations

1. Append

Add a new row to the end of the sheet.

Two Modes:

Object Mode - Recommended

Map values by column names, safer and easier to maintain.

Example:

{
  "Employee ID": "{{ $json.body.employeeId }}",
  "Name": "{{ $json.body.name }}",
  "Department": "{{ $json.body.department }}",
  "Position": "{{ $json.body.position }}",
  "Salary": "{{ $json.body.salary }}"
}

Features:

• ✅ Automatically read Excel headers (first row)
• ✅ Intelligently map by column names
• ✅ Ignore unknown columns with warnings in response
• ✅ Column order can be arbitrary
• ✅ Missing columns automatically filled with empty values

Array Mode

Specify values in exact column order.

Example:

["E100", "John Doe", "HR", "Manager", "70000"]

Note: Value order must exactly match Excel column order.

2. Read

Read data from Excel file.

Parameters:

• file: File name (e.g., employees.xlsx)
• sheet: Sheet name (default: Sheet1)
• range: Cell range (e.g., A1:D10, leave empty to read all)

Output:

• Auto-convert first row to column names if headers detected
• Return array of objects with headers as keys
• Return raw data array if no headers

3. Update

Update existing row data by looking up specific column values.

Process Modes:

All Matching Records - Default

Update all matching rows, suitable for scenarios where multiple rows share the same value.

Example: Update all IT department employees

{
  "operation": "update",
  "lookupColumn": "Department",
  "lookupValue": "IT",
  "processMode": "all",
  "valuesToSet": {
    "Status": "Reviewed",
    "Review Date": "2026-01-06"
  }
}

First Match Only

Update only the first matching record, suitable for unique identifier lookups.

Example: Update specific employee data

{
  "operation": "update",
  "lookupColumn": "Employee ID",
  "lookupValue": "E100",
  "processMode": "first",
  "valuesToSet": {
    "Salary": "80000",
    "Position": "Senior Manager"
  }
}

💡 Usage Tips:

• When looking up by unique identifiers (Employee ID, Email), use processMode: "first" for better performance
• Use processMode: "all" when updating multiple records that share the same value
• Default is "all" to ensure no matching records are missed

4. Delete

Delete rows from the sheet by looking up specific column values.

Process Modes:

All Matching Records - Default

Delete all matching rows.

Example: Delete all terminated employees

{
  "operation": "delete",
  "lookupColumn": "Status",
  "lookupValue": "Terminated",
  "processMode": "all"
}

First Match Only

Delete only the first matching record.

Example: Delete specific employee

{
  "operation": "delete",
  "lookupColumn": "Employee ID",
  "lookupValue": "E100",
  "processMode": "first"
}

⚠️ Important:

• Delete operations cannot be undone, use with caution
• When looking up by unique identifiers, use processMode: "first"
• Verify lookup conditions carefully to avoid accidental data loss

🎨 Usage Examples

Example 1: Webhook Form to Excel

Perfect for scenarios with multiple simultaneous form submissions!

┌──────────────────┐
│ Webhook          │  Receive form submission
│ POST /submit     │
└────────┬─────────┘
         │
         ▼
┌──────────────────┐
│ Excel API        │  Operation: Append (Object Mode)
│                  │  File: registrations.xlsx
│                  │  Values: {
│                  │    "Name": "{{ $json.body.name }}",
│                  │    "Email": "{{ $json.body.email }}",
│                  │    "Phone": "{{ $json.body.phone }}",
│                  │    "Submit Time": "{{ $now }}"
│                  │  }
└────────┬─────────┘
         │
         ▼
┌──────────────────┐
│ Respond Webhook  │  Return success message
└──────────────────┘

HTML Form:

<form id="registrationForm">
  <input type="text" name="name" placeholder="Name" required>
  <input type="email" name="email" placeholder="Email" required>
  <input type="tel" name="phone" placeholder="Phone" required>
  <button type="submit">Submit</button>
</form>

<script>
document.getElementById('registrationForm').addEventListener('submit', async (e) => {
  e.preventDefault();
  const formData = new FormData(e.target);
  await fetch('YOUR_WEBHOOK_URL', {
    method: 'POST',
    headers: {'Content-Type': 'application/json'},
    body: JSON.stringify(Object.fromEntries(formData))
  });
  alert('Submitted successfully!');
});
</script>

Example 2: Daily Report Generation

┌──────────────────┐
│ Schedule         │  Every day at 9:00 AM
│ 0 9 * * *        │
└────────┬─────────┘
         │
         ▼
┌──────────────────┐
│ Excel API        │  Operation: Read
│ (Read)           │  File: sales.xlsx
└────────┬─────────┘
         │
         ▼
┌──────────────────┐
│ Filter           │  Filter today's records
└────────┬─────────┘
         │
         ▼
┌──────────────────┐
│ Send Email       │  Send daily report
└──────────────────┘

Example 3: Update Salary by Employee ID

┌──────────────────┐
│ Webhook          │  Receive update request
│ POST /update     │  { "employeeId": "E100", "salary": 85000 }
└────────┬─────────┘
         │
         ▼
┌──────────────────┐
│ Excel API        │  Operation: Update
│                  │  Identify By: Lookup
│                  │  Lookup Column: Employee ID
│                  │  Lookup Value: {{ $json.body.employeeId }}
│                  │  Process Mode: First Match Only
│                  │  Values To Set: { "Salary": "{{ $json.body.salary }}" }
└────────┬─────────┘
         │
         ▼
┌──────────────────┐
│ Respond Webhook  │  Return update result
└──────────────────┘

Example 4: Batch Department Status Update

Use Case: Review all employees in a department at once

┌──────────────────┐
│ Webhook          │  Receive batch review request
│ POST /approve    │  { "department": "IT", "status": "Reviewed" }
└────────┬─────────┘
         │
         ▼
┌──────────────────┐
│ Excel API        │  Operation: Update
│                  │  Identify By: Lookup
│                  │  Lookup Column: Department
│                  │  Lookup Value: {{ $json.body.department }}
│                  │  Process Mode: All Matching Records
│                  │  Values To Set: {
│                  │    "Status": "{{ $json.body.status }}",
│                  │    "Review Date": "{{ $now.format('YYYY-MM-DD') }}",
│                  │    "Reviewer": "{{ $json.body.reviewer }}"
│                  │  }
└────────┬─────────┘
         │
         ▼
┌──────────────────┐
│ Respond Webhook  │  Return: Updated N records
└──────────────────┘

Example 5: Clean Up Expired Data

Use Case: Periodically delete employee records terminated over a year ago

┌──────────────────┐
│ Schedule         │  Execute on 1st of month
│ 0 0 1 * *        │
└────────┬─────────┘
         │
         ▼
┌──────────────────┐
│ Excel API        │  Operation: Delete
│                  │  Identify By: Lookup
│                  │  Lookup Column: Status
│                  │  Lookup Value: Terminated
│                  │  Process Mode: All Matching Records
└────────┬─────────┘
         │
         ▼
┌──────────────────┐
│ Send Email       │  Notify admin: Cleaned N records
└──────────────────┘

🧪 Concurrent Testing

Test 10 simultaneous submissions:

// concurrent_test.js
const promises = [];
for (let i = 0; i < 10; i++) {
  promises.push(
    fetch('YOUR_WEBHOOK_URL', {
      method: 'POST',
      headers: {'Content-Type': 'application/json'},
      body: JSON.stringify({
        EmployeeID: `E${String(i).padStart(3, '0')}`,
        Name: `Test User ${i}`,
        Timestamp: new Date().toISOString()
      })
    })
  );
}

await Promise.all(promises);
console.log('All requests completed!');

Result: All 10 records will be safely written to Excel without data loss or corruption!

⚠️ Troubleshooting

Issue 1: Node Not Showing in n8n

Solution:

# Restart n8n
pkill -f n8n
n8n start

# Or with pm2
pm2 restart n8n

Issue 2: API Connection Failed

Solution:

• Check if Excel API Server is running: curl http://localhost:8000/
• Verify API URL in credentials is correct
• Check API Token is correct
• Check firewall settings

Issue 3: "Parameter Not Found" Error

Cause: Incorrect parameter name configuration

Solution:

• Confirm correct Append Mode is selected (Object or Array)
• Object Mode: Use appendValuesObject parameter
• Array Mode: Use appendValuesArray parameter
• Check JSON format is correct

Issue 4: "File Lock" Error

Cause: Too many concurrent requests or API server issues

Solution:

• Wait a moment and retry
• Check API server status
• Restart Excel API Server if necessary

🔐 Security

Best Practices

1. Use Strong API Token

   # Generate secure token
   openssl rand -hex 32
   

2. Use HTTPS in Production

   • Set up reverse proxy (Nginx)
   • Use SSL certificate

3. Restrict Access

   • Allow only trusted networks to access API URL
   • Use VPN for remote access

4. Regular Backups

   • Set up automatic backups of Excel files
   • Store backups in secure location

📊 Performance Optimization Tips

1. Specify Range When Reading

// ❌ Bad: Read entire file
range: ""

// ✅ Good: Only read needed range
range: "A1:D100"

2. Use Efficient Workflows

• Combine related operations in one workflow
• Reduce number of API calls
• Use caching appropriately

🆕 Latest Features

🎉 Automatic Type Conversion (v1.0.3)

• ✅ Smart Type Detection: Automatically convert strings to appropriate data types
• ✅ Number Conversion: "123" → 123, "45.67" → 45.67
• ✅ Boolean Conversion: "true" → true, "false" → false
• ✅ Null Conversion: "null" or empty string → null
• ✅ Date Conversion: ISO format date strings auto-convert ("2024-01-15")
• ✅ Preserve Typed Values: Numbers, booleans, etc. remain unchanged
• ✅ All Operations: Supported in both Append and Update operations

Example:

{
  "EmployeeID": "E001",      // Remains string
  "Age": "30",               // Auto-converts to number 30
  "Salary": "50000.50",     // Auto-converts to 50000.50
  "IsActive": "true",        // Auto-converts to boolean true
  "TerminationDate": "null", // Auto-converts to null
  "HireDate": "2020-01-15"   // Auto-converts to date format
}

Object Mode

• ✅ Uses /api/excel/append_object API
• ✅ Automatically reads Excel headers (first row)
• ✅ Intelligently maps by column names
• ✅ Ignores unknown columns with warnings in response
• ✅ No need to remember column order

Advanced Update and Delete

• ✅ Support operations by column value lookup
• ✅ Can update specific columns without affecting others
• ✅ Process modes: all matching records or first match only

Lookup Column Selection

• ✅ Dynamic dropdown selection of Excel headers
• ✅ Support for Chinese and special character column names
• ✅ Automatic URL encoding for special characters
• ✅ Enhanced user experience with visual column selection

🤝 Contributing

Contributions are welcome!

1. Fork this repository
2. Create your feature branch: git checkout -b feature/AmazingFeature
3. Commit your changes: git commit -m 'Add some AmazingFeature'
4. Push to the branch: git push origin feature/AmazingFeature
5. Open a Pull Request

📄 License

MIT License - see LICENSE file

🔗 Related Projects

• Excel API Server - Backend API server (Required)
• n8n - Workflow automation tool

📧 Support

• Work Items: GitLab Work Items
• Merge Requests: GitLab Merge Requests
• Email: hueyan.chen@gmail.com
• n8n Community: n8n Forum

⭐ Star History

If this project helps you, please give it a ⭐!

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