# Freshbooks API  Add-Ons, Billing, and Webhooks

**Author:** kinlane  
**Canonical:** https://apievangelist.com/2011/04/13/freshbooks-apiaddons-billing-and-webhooks/

I am slowly working my way through [hundreds of APIs](http://www.programmableweb.com/apis/directory "hundreds of APIs") and doing business reviews of their approach to delivering their APIs.

At API Evangelist I'm focused on the business of APIs, with a minor focus on the technology behind those APIs. So when I publish a business review of an API, I will add it to my API database, then move on.

That is, unless I identify a story -- an innovative approach, monetization strategy, or anything that I feel needs to be talked about in more detail.

While reviewing the [Freshbooks API](http://developers.freshbooks.com/ "Freshbooks API") I found three notable building blocks:

*   **[Application Billing](http://developers.freshbooks.com/billing/ "Application Billing")** - A built in billing and payment framework for Freshbook applications and beyond
*   **[Webhooks](http://developers.freshbooks.com/webhooks/ "Webhooks")** - Framework for enabling application callbacks, URLs where the Freshbook system can send notifications to third party applications
*   [Self-Service Application Frameworks](http://community.freshbooks.comkinlane-productions2.s3.amazonaws.comStor</strong>e</a> - Application store and development platform for developers to build custom apps, showcase,  and sell to Freshbook customers.</li>
    </ul>
    <a title= "Freshbooks Add-On Store") like the Freshbooks Add-On Store are growing more common. I've talked about similar systems from [Box.net](http://apievangelist.com/2011/04/08/box-net-openbox/ "Box.net") and [Google Apps Marketplace](http://apievangelist.com/2011/04/08/google-apps-marketplace/ "Google Apps Marketplace"). The Freshbooks Add-On store is not 100% self-service, but it is close. [![](https://kinlane-images.s3.amazonaws.com/apievangelist/freshbooks-leaf.jpg)](http://www.freshbooks.com/) Webhooks are nothing new, but Freshbook offers a standardized approach to deploying web-hooks that makes them easy for developer to use.
    
    A built in payment system is definitely a notable [API building block](http://www.apievangelist.com/ecosystem-building-blocks.php "API Building Block"). Providing developers with a baked-in payment system for handling application monetization is very innovative.
    
    Where do these three building blocks fit into the big picture? I try to build profiles for common API building blocks, I don't have profiles for self-service application frameworks, webhooks, and payment systems, but as I evaluate more I will define these as more innovative building blocks for API owners to use.
    
    I will definitely be keeping an eye on the [Freshbook](http://www.freshbooks.com/ "Freshbook") approach to their API.