Fixing Paystack Integration in Laravel Deployment: URI must be a string or UriInterface

Deploying a Laravel application with Paystack integration can sometimes lead to unexpected issues. Recently, I faced an InvalidArgumentException error during deployment:

InvalidArgumentException: URI must be a string or UriInterface in .../public_html/vendor/guzzlehttp/psr7/src/Utils.php:461

The Issue

The error originated from the guzzlehttp/psr7 package, which is commonly used for handling HTTP requests in Laravel applications. The problem was traced to the Paystack configuration in config/paystack.php:

<?php

return [

    'publicKey' => getenv('PAYSTACK_PUBLIC_KEY'),
    'secretKey' => getenv('PAYSTACK_SECRET_KEY'),
    'paymentUrl' => getenv('PAYSTACK_PAYMENT_URL'),
    'merchantEmail' => getenv('MERCHANT_EMAIL'),

];

The getenv() function was not retrieving environment variables as expected in the production environment, although it worked fine locally.

The Solution

Replacing getenv() with Laravel's env() helper function fixed the issue. Here's the updated config/paystack.php file:

<?php

return [

    'publicKey' => env('PAYSTACK_PUBLIC_KEY'),
    'secretKey' => env('PAYSTACK_SECRET_KEY'),
    'paymentUrl' => env('PAYSTACK_PAYMENT_URL'),
    'merchantEmail' => env('MERCHANT_EMAIL'),

];

Why This Works

The env() helper function in Laravel retrieves environment variables from the .env file, ensuring consistent configuration across different environments. In contrast, getenv() might not work reliably in all server setups.

Project Setup Details

• PHP version: 8.1.29 (cli)
• Laravel version: 10.10
• Composer package: unicodeveloper/laravel-paystack

Step-by-Step Guide to Implementing the Solution

1. Edit the Configuration File: Replace getenv() with env() in config/paystack.php.

<?php

return [

    'publicKey' => env('PAYSTACK_PUBLIC_KEY'),
    'secretKey' => env('PAYSTACK_SECRET_KEY'),
    'paymentUrl' => env('PAYSTACK_PAYMENT_URL'),
    'merchantEmail' => env('MERCHANT_EMAIL'),

];

2. Verify Environment Variables: Ensure your .env file contains the correct Paystack environment variables.

PAYSTACK_PUBLIC_KEY=your-public-key
PAYSTACK_SECRET_KEY=your-secret-key
PAYSTACK_PAYMENT_URL=https://api.paystack.co
MERCHANT_EMAIL=your-email@example.com

3. Clear Config Cache: Clear the Laravel config cache to ensure the changes take effect.

php artisan config:cache

4. Deploy and Test: Deploy your application and test the Paystack integration to confirm the issue is resolved.

Conclusion

Using the env() function instead of getenv() ensures your Laravel application retrieves environment variables reliably in various deployment environments. This simple change resolved the InvalidArgumentException and ensured smooth integration with Paystack.

Happy coding!