Avalara provides a number of tax calculation APIs based on the destination zip code, the ship-from zip code, and additional integrations that can be customized.
If you are integrating with a secondary accounting system (e.g. Acumatica), please specify that in your question headline to allow for filtering.
If you are tempted to post an answer with the link to the developer documentation, (to wit, https://developer.avalara.com/), don't. A lot of times their documentation is dense and unhelpful.