> ## Documentation Index
> Fetch the complete documentation index at: https://docs.symmetry.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Data and accuracy

> How CBS handles calculation data across widgets and the API, and where the accuracy of its results comes from.

Widgets and the API run the same calculation against the same tax data, so everything on this page applies to both [integration paths](/cbs/overview/choose-path).

## Stateless calculations

Calculations are **stateless**: CBS takes your inputs, runs the calculation, and returns the result. It does **not persist calculation inputs or results to a database**, and it holds no session state between requests. A widget calls the same API, so the same is true whichever path you use.

## Where accuracy comes from

CBS tax calculations are performed by the Symmetry Tax Engine against Symmetry's maintained tax data, so a CBS result matches what the engine returns for the same inputs. Monetary results are returned to the cent (two decimal places).

Because tax tables change over time, pin an explicit `checkDate` when you need a repeatable result. See [Test calculations against known values](/cbs/api/test-known-values).