# Updating Preset Value of a Step UDF through API

Use the API to update the preset value of a user-defined field (UDF)/custom field configured on a step.

From your test server:

1. GET a chosen UDF/custom field.
2. Do a PUT and include a new line.

For example, to add 'My new preset', insert the preset (My new preset), after your last value in your XML:

```
........

<preset>Your last preset</preset>

<preset>My new preset</preset>

<is-required>Your original value</is-required>

<attach-to-category>Your original value</attach-to-category>

</cnf:field>
```

This tool is powerful when integrating with external systems and combined with the Begin Work trigger. For example, it can be used to reach out to an external source with a script, initiated with the Begin Work trigger. The script makes sure that the presets for the Step Details UDFs/custom fields are always up to date and in sync with the server—before entering the Record Details screen.


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