Tax infrastructure, one API away

Sales-tax quotes across ~11,900 U.S. jurisdictions from official state sources. A transaction ledger that splits every sale by jurisdiction, rolls up into merchant filing engagements on an automatic monthly calendar, and produces period summaries already in filing shape — with SST e-filing on the way. Plus federal tax estimates and AI document extraction. All metered under one partner key.

Your API key

The key stays in this browser tab only — it is never stored on our servers in plaintext. Don't have a key? Email sales@knottheory.ai. Or start with the API reference.