# Retrieve parameters and units of measure

Source: https://developer.avalara.com/products/crossborder/integration-guides/avatax-for-cdit/zmf8961165591555/

Guide: AvaTax Cross-Border (Customs Duty and Import Tax)

# Retrieve parameters and units of measure

Learn how to retrieve classification parameters, input parameters, and units of measure for transactions.

When specifying items in a transaction, the request expects you to include classification parameters, input parameters, and units of measure. You can run the following definitions APIs to retrieve this information before creating a transaction:

-   [ListClassificationParametersUsage](https://developer.avalara.com/api-reference/avatax/rest/v2/methods/Definitions/ListClassificationParametersUsage/)
-   [ListParameters](https://developer.avalara.com/api-reference/avatax/rest/v2/methods/Definitions/ListParameters/)
-   [ListUnitOfMeasurement](https://developer.avalara.com/api-reference/avatax/rest/v2/methods/Definitions/ListUnitOfMeasurement/)