# Automating Tekla Tedds library calculations

## Automate a Tekla Tedds calculation

If you want to automate a calculation included in the Tekla Tedds engineering library you will first need to review that specific calculation to determine the input and output variables used.

Specific calculations do not have their own API, instead you use the Tekla Tedds API to define the input variables that you would normally enter manually into the user interface of that calculation and you then query the results which the calculation has created and used in the output.

## Input and output variables

To determine the input and output variables used in a specific calculation consider the following:

- Read the calculation notes. Some calculations will include dedicated documentation of the key input and output variables used. Using the library access system, open the calculation index and browse to the folder of the calculation you're interested in and open the
**Components**item. If the calculation has dedicated variable documentation it will be listed beneath the calculation notes item. - Start the calculation and read through the user interface, some calculations include the names of the variables used for each input in the user interface.
- Finish the calculation and read through the output, the majority of the input and output variables will be documented in the full output.
- Finish the calculation and read through the variables listed in the
**Variable Manager**.

## Start learning in Tekla Tedds for Word

When you want to start automating a calculation begin the learning process by starting in Tekla Tedds for Word. Assign the input variables you want to pre-define directly in the Microsoft Word document immediately before the call to the calculation.

Immediately following the calculation insert expressions which query the results you are interested in. Once you have used this technique to create a working Tekla Tedds for Word document then apply the same principal using the Tekla Tedds API.