# Rule Engine Unique Functions

### Overview

This guide details the unique functions available within the Pepperi JS Client Side API’s Rule Engine, specifically **GetValueByApiName** and **SetValueByApiName**. 

These functions are exclusive to the Rule Engine and are used to retrieve and set values in User Defined Fields (UDFs) without triggering additional calculations.

***

### Unique Rule Engine Functions

#### GetValueByApiName

* **Description:** Retrieves a single value from the current object’s field, returning a dynamic type based on the field’s content.
* **Use Case:** Ideal for accessing data from the current object, such as a Transaction Line’s associated Transaction UUID.
* **Example:**

  ```javascript
  let value = GetValueByApiName("Transaction.UUID");
  ```

  * In this case, if the Calculated Formula is defined on a Transaction Line UDF, it retrieves the Transaction’s UUID.

#### SetValueByApiName

* **Description:** Sets a single value to the current object’s field, returning a Boolean to indicate success.
* **Use Case:** Useful for updating UDF values without invoking further calculations.
* **Example:**

  ```javascript
  let res = SetValueByApiName("TSAMessage", "hello");
  ```

{% hint style="warning" %}
**Note**: Setting a value with SetValueByApiName does not trigger any additional calculation logic.
{% endhint %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://apidocs.pepperi.com/rule-engine-unique-functions.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.