How to Get Invoices with the Xero API in PHP

by Endgrate Team 2024-06-14 5 min read

Xero homepage

Introduction to Xero API Integration

Xero is a powerful cloud-based accounting software platform designed to help small and medium-sized businesses manage their finances efficiently. With features like invoicing, payroll, and expense tracking, Xero provides a comprehensive solution for businesses looking to streamline their financial operations.

Integrating with Xero's API allows developers to automate and enhance financial workflows, such as retrieving invoice data for reporting or analysis. For example, a developer might use the Xero API to fetch invoices and integrate them into a custom dashboard, providing real-time insights into a company's financial health.

Setting Up Your Xero Sandbox Account for API Integration

Before you can start interacting with the Xero API, you'll need to set up a sandbox account. This allows you to test your integration without affecting live data. Xero provides a demo company that you can use for this purpose.

Creating a Xero Developer Account

To begin, you'll need a Xero developer account. If you don't have one, follow these steps:

  • Visit the Xero Developer Portal and sign up for a free account.
  • Once registered, log in to your developer account.

Accessing the Xero Demo Company

After logging in, you can access the Xero demo company, which acts as your sandbox environment:

  • Navigate to the "My Apps" section in your developer dashboard.
  • Select "Try the Demo Company" to access a pre-configured company with sample data.

Creating a Xero App for OAuth 2.0 Authentication

Since the Xero API uses OAuth 2.0 for authentication, you'll need to create an app to obtain the necessary credentials:

  • In the "My Apps" section, click on "New App."
  • Fill in the required details, such as the app name and company URL.
  • Set the redirect URI to a valid endpoint where you can handle OAuth responses.
  • Once created, note down the client ID and client secret, as you'll need these for authentication.

Configuring OAuth 2.0 Scopes for Xero API Access

To interact with invoices, you'll need to configure the appropriate scopes for your app:

  • In your app settings, navigate to the "Scopes" section.
  • Select the scopes related to invoices, such as accounting.transactions and accounting.settings.
  • Save your changes to update the app permissions.

With your sandbox account and app set up, you're now ready to start making API calls to retrieve invoices from Xero. For more details on OAuth 2.0 authentication, refer to the Xero OAuth 2.0 Guide.

Xero authentication documentation page.
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Making API Calls to Retrieve Xero Invoices Using PHP

To interact with the Xero API and retrieve invoices, you'll need to set up your PHP environment and make authenticated requests. This section will guide you through the process of configuring your PHP setup, installing necessary dependencies, and executing the API call to fetch invoices from Xero.

Setting Up Your PHP Environment for Xero API Integration

Before making API calls, ensure your PHP environment is properly configured:

  • Ensure you have PHP 7.4 or higher installed on your machine.
  • Install Composer, the PHP package manager, to manage dependencies.

Installing Required PHP Libraries for Xero API Access

You'll need to install the Guzzle HTTP client to handle HTTP requests and responses:

composer require guzzlehttp/guzzle

Executing the API Call to Fetch Invoices from Xero

With your environment set up, you can now write the PHP code to retrieve invoices:


require 'vendor/autoload.php';

use GuzzleHttp\Client;

$client = new Client();
$accessToken = 'Your_Access_Token';
$tenantId = 'Your_Tenant_Id';

$response = $client->request('GET', 'https://api.xero.com/api.xro/2.0/Invoices', [
    'headers' => [
        'Authorization' => 'Bearer ' . $accessToken,
        'Xero-tenant-id' => $tenantId,
        'Accept' => 'application/json',
    ]
]);

$data = json_decode($response->getBody(), true);

foreach ($data['Invoices'] as $invoice) {
    echo 'Invoice ID: ' . $invoice['InvoiceID'] . "\n";
    echo 'Amount Due: ' . $invoice['AmountDue'] . "\n";
}

Replace Your_Access_Token and Your_Tenant_Id with the actual values obtained during the OAuth 2.0 authentication process.

Verifying Successful API Requests and Handling Errors

After running the script, you should see a list of invoices printed in your terminal. To verify the request's success, check the response status code:


if ($response->getStatusCode() === 200) {
    echo "Invoices retrieved successfully.";
} else {
    echo "Failed to retrieve invoices. Status code: " . $response->getStatusCode();
}

For more detailed error handling, refer to the Xero API documentation for common error codes and their meanings.

Xero API call documentation page.

Conclusion and Best Practices for Xero API Integration in PHP

Integrating with the Xero API using PHP allows developers to automate financial processes and gain valuable insights into business operations. By following the steps outlined in this guide, you can efficiently retrieve invoice data and incorporate it into your applications.

Best Practices for Secure and Efficient Xero API Integration

  • Secure Storage of Credentials: Always store your client ID, client secret, and access tokens securely. Consider using environment variables or a secure vault to manage sensitive information.
  • Handle Rate Limiting: Xero's API has rate limits in place. Be sure to implement error handling for rate limit responses and consider exponential backoff strategies to manage retries. For more details, refer to the Xero API rate limits documentation.
  • Data Transformation and Standardization: When integrating invoice data into your systems, ensure that data fields are transformed and standardized to match your application's requirements.

Streamline Your Integration Process with Endgrate

If managing multiple integrations is becoming a challenge, consider using Endgrate to simplify the process. Endgrate provides a unified API endpoint that connects to various platforms, including Xero, allowing you to focus on your core product while outsourcing complex integrations. Learn more about how Endgrate can enhance your integration experience by visiting Endgrate's website.

By leveraging the power of Xero's API and following best practices, you can create robust financial applications that drive business success.

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