FiveTech Software tech support forums

Yes, many developers have integrated with QuickBooks Online (QBO). For integration, the most commonly used SDK is **Intuit’s QuickBooks Online SDK**. It provides a seamless way to interact with QBO’s API. Here’s a breakdown:

### Common SDKs for QuickBooks Online Integration:
1. **QuickBooks Online SDKs:**
- **.NET SDK**: Great for C# developers.
- **Java SDK**: Perfect for Java developers.
- **PHP SDK**: Suitable for PHP-based applications.

2. **REST API Directly**: If you don’t want to rely on the SDKs or are using a language like Python, JavaScript, or Harbour (your stack), you can interact directly with the QuickBooks Online REST API. This gives you more control but requires manual handling of OAuth2 authentication and API calls.

### Key Points for Integration:
- **Authentication**: QuickBooks Online uses **OAuth 2.0** for authentication. You’ll need to register your app in Intuit’s Developer Portal to get API keys and set up the redirect URIs.
- **API Documentation**: The [QuickBooks Online API documentation](https://developer.intuit.com/app/develo ... et-started) provides detailed guidance on endpoints for customer management, invoices, payments, etc.
- **Sandbox Environment**: Intuit offers a sandbox for testing integrations before going live.

### Regarding QuickBooks Desktop:
You’re correct that Intuit is phasing out the desktop versions of QuickBooks for certain markets, pushing users towards QuickBooks Online. However, if you're working with legacy desktop systems, they rely on the **QuickBooks Desktop SDK** or **QBXML** (for SOAP-based integrations). But for long-term solutions, shifting to QuickBooks Online integration makes the most sense.