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Overview

CompuTécnicos integrates with PayPal to process online payments. The platform supports both sandbox (testing) and production environments, with automatic currency conversion from Colombian Pesos (COP) to US Dollars (USD).

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Prerequisites

Before configuring PayPal:

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Configuration Parameters

The PayPal integration is configured in config/paypal_config.php using environment variables:
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PAYPAL_CLIENT_ID
string
required
Your PayPal REST API Client ID.How to obtain:
  1. Log in to PayPal Developer Dashboard
  2. Navigate to “Apps & Credentials”
  3. Create a new app or select an existing one
  4. Copy the Client ID
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PAYPAL_CLIENT_SECRET
string
required
Your PayPal REST API Client Secret.
This is a sensitive credential. Never expose it in client-side code, commit it to version control, or share it publicly.
Found in the same location as the Client ID in the PayPal Developer Dashboard.
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PAYPAL_ENVIRONMENT
string
default:"sandbox"
The PayPal environment to use.Valid values:
  • sandbox - Test environment for development
  • production - Live environment for real transactions
Always test thoroughly in sandbox before switching to production.

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Additional Settings

The following settings are configured directly in config/paypal_config.php:
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currency
string
default:"USD"
The currency for PayPal transactions. Set to USD for international compatibility.
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exchange_rate_cop_to_usd
float
default:"0.00025"
Currency conversion rate from Colombian Pesos (COP) to US Dollars (USD).Default rate: 0.00025 (approximately 1 USD = 4000 COP)
This is a simplified conversion rate. For production use, consider integrating with a real-time currency exchange API.

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Setup Instructions

1

Create PayPal App

  1. Go to PayPal Developer Dashboard
  2. Click “Apps & Credentials”
  3. Click “Create App”
  4. Choose a name for your app (e.g., “CompuTécnicos”)
  5. Select “Merchant” as the app type
  6. Click “Create App”
2

Get API Credentials

After creating your app:
  1. Copy the Client ID from the app details page
  2. Click “Show” under Secret and copy the Client Secret
  3. Save these credentials securely
3

Configure Environment Variables

Add the credentials to your .env file:
# PayPal Sandbox (for testing)
PAYPAL_CLIENT_ID=your_sandbox_client_id
PAYPAL_CLIENT_SECRET=your_sandbox_client_secret
PAYPAL_ENVIRONMENT=sandbox
4

Test in Sandbox

  1. Use PayPal’s sandbox test accounts
  2. Create a personal (buyer) test account
  3. Process test transactions using the sandbox credentials
  4. Verify payments appear in the sandbox dashboard
5

Switch to Production

When ready for live transactions:
  1. Create a production app in PayPal Developer Dashboard
  2. Get production Client ID and Secret
  3. Update your .env file:
# PayPal Production (live transactions)
PAYPAL_CLIENT_ID=your_production_client_id
PAYPAL_CLIENT_SECRET=your_production_client_secret
PAYPAL_ENVIRONMENT=production
Production transactions involve real money. Ensure thorough testing in sandbox first.

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Configuration File Structure

The config/paypal_config.php file returns an array with the following structure: 
return [
    'client_id' => getenv('PAYPAL_CLIENT_ID') ?: 'default_client_id',
    'client_secret' => getenv('PAYPAL_CLIENT_SECRET') ?: 'default_secret',
    'environment' => getenv('PAYPAL_ENVIRONMENT') ?: 'sandbox',
    'currency' => 'USD',
    'exchange_rate_cop_to_usd' => 0.00025
];

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Currency Conversion

Since CompuTécnicos operates in Colombia with prices in COP, but PayPal transactions use USD: Conversion Formula: 
$amountUSD = $amountCOP * 0.00025;
Example:
  • Product price: 100,000 COP
  • PayPal amount: 100,000 × 0.00025 = 25 USD
The default exchange rate (0.00025) is approximate. For accurate, real-time rates, integrate with a currency exchange API like:

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Security Best Practices

Follow these security guidelines to protect your PayPal integration:
1

Protect API Credentials

  • Store Client ID and Secret in environment variables only
  • Never hardcode credentials in source code
  • Add .env to .gitignore
  • Use different credentials for development and production
2

Use HTTPS

Always use HTTPS in production. PayPal requires secure connections for API calls.
3

Validate Payments Server-Side

Never trust client-side payment confirmations. Always verify payment status through PayPal’s API on the server.
4

Implement Webhooks

Set up PayPal webhooks to receive real-time payment notifications and handle asynchronous events.
5

Monitor Transactions

Regularly review transactions in the PayPal dashboard for suspicious activity.
6

Handle Errors Gracefully

Implement proper error handling for failed payments, network issues, and API errors.

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Testing in Sandbox

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Creating Test Accounts

  1. Go to Sandbox Accounts
  2. Click “Create Account”
  3. Select “Personal” (Buyer) account type
  4. Set the country to your target market
  5. Configure the balance and credit card details
  6. Click “Create Account”

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Test Credentials

PayPal sandbox provides:
  • Test email addresses
  • Test passwords
  • Virtual balance
  • Fake credit card numbers

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Making Test Payments

  1. Use your sandbox Client ID and Secret
  2. Process a payment in your application
  3. Log in with a sandbox buyer account
  4. Complete the payment flow
  5. Verify the transaction in the sandbox dashboard

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Troubleshooting

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Authentication Failed

Error: “Authentication failed” or “Invalid client credentials” Solutions:
  • Verify Client ID and Secret are correct
  • Ensure you’re using sandbox credentials with PAYPAL_ENVIRONMENT=sandbox
  • Check for extra spaces or quotes in environment variables
  • Regenerate credentials in PayPal Developer Dashboard

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Currency Issues

Error: Payment amounts don’t match expected values Solutions:
  • Verify the exchange rate is set correctly
  • Check that amounts are being converted from COP to USD
  • Ensure currency is set to “USD” in the config
  • Round amounts to 2 decimal places for USD

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Environment Mismatch

Error: Transactions failing in production Solutions:
  • Verify you’re using production credentials, not sandbox
  • Ensure PAYPAL_ENVIRONMENT=production
  • Check that your PayPal business account is verified
  • Verify your app has production access enabled

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SSL/HTTPS Issues

Error: “SSL certificate verification failed” Solutions:
  • Ensure your server has up-to-date SSL certificates
  • Verify your PHP installation has cURL with SSL support
  • Check that your redirect URIs use HTTPS in production

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