n8n WordPress Integration Plugin

A WordPress plugin that integrates n8n workflows with WordPress through a custom REST API. This plugin creates a custom MySQL table and provides RESTful endpoints for inserting, retrieving, updating, and deleting data from n8n workflows.

Built with Object-Oriented Programming (OOP) principles featuring modular architecture, PSR-4 autoloading, and dependency injection.

Features

• ✅ Custom MySQL table for storing n8n workflow data
• ✅ RESTful API endpoints for full CRUD operations
• ✅ API key authentication for security
• ✅ JSON data support
• ✅ Metadata storage for additional context
• ✅ Automatic timestamp tracking (created_at, updated_at)
• ✅ Query filtering and pagination
• ✅ Clean uninstall (removes table and options)
• ✅ OOP Architecture with separation of concerns
• ✅ PSR-4 Autoloading for automatic class loading
• ✅ Modular Design easy to extend and maintain

Installation

1. Download or clone this repository into your WordPress plugins directory:

   cd wp-content/plugins/
   git clone https://github.com/itsomidho/n8n-wp-integration.git

2. Install Composer dependencies:

   cd n8n-wp-integration
   composer install --no-dev

3. Activate the plugin through the WordPress admin panel:

   • Navigate to Plugins → Installed Plugins
   • Find "n8n WordPress Integration"
   • Click Activate

4. The plugin will automatically create the custom database table wp_n8n_data (prefix may vary based on your WordPress configuration)

Architecture

This plugin follows modern OOP principles with a clean, modular structure:

n8n-wp-integration/
├── composer.json              # Composer configuration
├── n8n-wp-integration.php     # Bootstrap with autoloader check
├── includes/
│   ├── class-plugin.php       # Main orchestrator
│   ├── class-database.php     # Database operations
│   ├── class-api.php          # REST API endpoints
│   └── class-auth.php         # Enhanced authentication
└── uninstall.php              # Cleanup script

Key Benefits:

• Separation of Concerns: Each class has a single responsibility
• Composer PSR-4 Autoloading: Professional dependency management
• Enhanced Security: Improved Auth class with timing-safe comparisons
• Admin Notices: Clear error messages if Composer autoloader is missing
• Composer PSR-4 Autoloading: Automatic class loading with Composer
• Dependency Injection: Loose coupling for better testability
• Easy to Extend: Add new features without modifying existing code
• Maintainable: Clear structure makes updates simple

For detailed architecture documentation, see PLUGIN-STRUCTURE.md.

Configuration

Setting up API Key (Required)

API key authentication is required for all API endpoints. You have multiple options to set up your API key:

Option 1: Admin Settings Page (Recommended)

1. Navigate to Settings → n8n Integration in your WordPress admin
2. Click the "Generate API Key" button
3. Copy the generated key using the "Copy" button
4. Use the key in your n8n workflows

The admin page provides:

• One-click API key generation
• Easy copy-to-clipboard functionality
• Visual status indicators
• API key deletion option
• Usage instructions with examples

Option 2: WordPress Options

1. Add this line to your wp-config.php file or use the WordPress options:

   update_option('n8n_wp_api_key', 'your-secure-api-key-here');

2. Or run this in WordPress admin via a plugin like Code Snippets:

   update_option('n8n_wp_api_key', 'your-secure-api-key-here');

Replace your-secure-api-key-here with a strong, random string (minimum 32 characters).

Note: Without a configured API key, all API requests will be rejected with a 401 Unauthorized error.

API Documentation

Base URL

All endpoints are prefixed with: https://your-site.com/wp-json/n8n/v1/

Authentication

API key must be provided via HTTP header only:

X-N8N-API-Key: your-secure-api-key-here

Note: Query parameter authentication has been removed for security reasons. Only the X-N8N-API-Key header is accepted.

Endpoints

1. Insert Data

POST /wp-json/n8n/v1/insert

Insert new data from an n8n workflow.

Request Body:

{
  "workflow_id": "my-workflow-123",
  "data": {
    "name": "John Doe",
    "email": "john@example.com",
    "message": "Hello from n8n!"
  },
  "metadata": {
    "source": "contact-form",
    "ip": "192.168.1.1"
  }
}

Response (201 Created):

{
  "success": true,
  "message": "Data inserted successfully",
  "id": 1,
  "data": {
    "id": 1,
    "workflow_id": "my-workflow-123",
    "data": {
      "name": "John Doe",
      "email": "john@example.com",
      "message": "Hello from n8n!"
    },
    "metadata": {
      "source": "contact-form",
      "ip": "192.168.1.1"
    }
  }
}

2. Get Data

GET /wp-json/n8n/v1/data

Retrieve data with optional filtering and pagination.

Query Parameters:

• workflow_id (optional): Filter by workflow ID
• limit (optional, default: 10): Number of records to return
• offset (optional, default: 0): Offset for pagination

Example:

GET /wp-json/n8n/v1/data?workflow_id=my-workflow-123&limit=20&offset=0

Response (200 OK):

{
  "success": true,
  "count": 2,
  "data": [
    {
      "id": "2",
      "workflow_id": "my-workflow-123",
      "data": {...},
      "metadata": {...},
      "created_at": "2025-10-30 19:21:00",
      "updated_at": "2025-10-30 19:21:00"
    },
    {
      "id": "1",
      "workflow_id": "my-workflow-123",
      "data": {...},
      "metadata": {...},
      "created_at": "2025-10-30 19:20:00",
      "updated_at": "2025-10-30 19:20:00"
    }
  ]
}

3. Get Single Record

GET /wp-json/n8n/v1/data/{id}

Retrieve a specific record by ID.

Example:

GET /wp-json/n8n/v1/data/1

Response (200 OK):

{
  "success": true,
  "data": {
    "id": "1",
    "workflow_id": "my-workflow-123",
    "data": {...},
    "metadata": {...},
    "created_at": "2025-10-30 19:20:00",
    "updated_at": "2025-10-30 19:20:00"
  }
}

4. Update Data

PUT /wp-json/n8n/v1/update/{id}

Update an existing record.

Request Body:

{
  "data": {
    "name": "Jane Doe",
    "email": "jane@example.com"
  },
  "metadata": {
    "updated": true
  }
}

Response (200 OK):

{
  "success": true,
  "message": "Data updated successfully",
  "id": 1
}

5. Delete Data

DELETE /wp-json/n8n/v1/delete/{id}

Delete a record by ID.

Example:

DELETE /wp-json/n8n/v1/delete/1

Response (200 OK):

{
  "success": true,
  "message": "Data deleted successfully"
}

Usage Examples

Using cURL

Insert Data:

curl -X POST https://your-site.com/wp-json/n8n/v1/insert \
  -H "Content-Type: application/json" \
  -H "X-N8N-API-Key: your-secure-api-key-here" \
  -d '{
    "workflow_id": "my-workflow-123",
    "data": {
      "name": "John Doe",
      "email": "john@example.com"
    }
  }'

Get Data:

curl -X GET "https://your-site.com/wp-json/n8n/v1/data?workflow_id=my-workflow-123&limit=10" \
  -H "X-N8N-API-Key: your-secure-api-key-here"

Using n8n HTTP Request Node

1. Add an HTTP Request node to your workflow
2. Configure the node:
   • Method: POST (or GET, PUT, DELETE as needed)
   • URL: https://your-site.com/wp-json/n8n/v1/insert
   • Authentication: None (we use custom header)
   • Headers:
     • Name: X-N8N-API-Key
     • Value: your-secure-api-key-here
   • Body:

     {
       "workflow_id": "{{$node["Trigger"].json["workflow_id"]}}",
       "data": "{{$json}}"
     }

Using JavaScript (Fetch API)

fetch('https://your-site.com/wp-json/n8n/v1/insert', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'X-N8N-API-Key': 'your-secure-api-key-here'
  },
  body: JSON.stringify({
    workflow_id: 'my-workflow-123',
    data: {
      name: 'John Doe',
      email: 'john@example.com'
    },
    metadata: {
      source: 'web-form'
    }
  })
})
.then(response => response.json())
.then(data => console.log(data))
.catch(error => console.error('Error:', error));

Database Schema

The plugin creates a table with the following structure:

CREATE TABLE wp_n8n_data (
  id bigint(20) UNSIGNED NOT NULL AUTO_INCREMENT,
  workflow_id varchar(255) NOT NULL,
  data longtext NOT NULL,
  metadata longtext DEFAULT NULL,
  created_at datetime DEFAULT CURRENT_TIMESTAMP,
  updated_at datetime DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (id),
  KEY workflow_id (workflow_id),
  KEY created_at (created_at)
);

Error Handling

The API returns appropriate HTTP status codes:

• 200 OK: Successful GET, PUT, DELETE operations
• 201 Created: Successful POST (insert) operation
• 401 Unauthorized: Invalid or missing API key
• 404 Not Found: Record not found
• 500 Internal Server Error: Database or server error

Error response format:

{
  "code": "rest_forbidden",
  "message": "Invalid API key",
  "data": {
    "status": 401
  }
}

Security Considerations

1. Always set an API key in production environments
2. Use HTTPS for all API requests to encrypt data in transit
3. Store API keys securely (environment variables, secret managers)
4. Regularly rotate API keys
5. Monitor API usage for unusual patterns
6. Consider rate limiting for production use

Uninstalling

When you uninstall the plugin through WordPress:

1. The custom database table wp_n8n_data will be deleted
2. All stored data will be permanently removed
3. Plugin options will be cleaned up

Warning: This action cannot be undone. Make sure to backup your data before uninstalling.

Requirements

• WordPress 5.0 or higher
• PHP 7.4 or higher
• MySQL 5.6 or higher

Support

For issues, questions, or contributions, please visit the GitHub repository.

License

This plugin is licensed under the GPL v2 or later.

Changelog

Version 1.0.0

• Initial release
• Custom REST API endpoints for CRUD operations
• Custom MySQL table for data storage
• API key authentication
• JSON data support
• Metadata support
• Automatic timestamp tracking