The Avalara AvaTax APIs allow you to connect your web cart or accounting software to realtime tax calculation and address validation services. You can just retrieve tax amounts, but your transactions can also be recorded for reporting and tax filing. We have a RESTful API, class wrappers (adapters) for PHP, Java, and .NET compiled from the SOAP API, or you can build your own wrappers directly from the address and tax service SOAP WSDLs.
The Avalara CertCapture APIs enable you to retrieve or update CertCapture data from a remote application. This allows applications to interact with customer and certificate records, and to send automated certificate requests to customers. CertCapture may be used as a stand-alone certificate management solution, or in conjunction with AvaTax.