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

# Logic Node

> Write custom JavaScript or TypeScript to transform and compute data inside a DotPortion workflow.

# Logic Node

The **Logic Node** allows you to write **custom JavaScript or TypeScript code** to process, transform, and compute data inside a DotPortion workflow.

It gives you full flexibility when visual configuration is not enough, while still keeping execution secure and isolated.

***

## What the Logic Node Does

The Logic Node is responsible for:

* Transforming incoming data
* Performing calculations
* Restructuring objects
* Combining data from multiple nodes
* Preparing data for database or response nodes

It works like a **server-side function** that runs during workflow execution.

***

<img src="https://mintcdn.com/dotportion/RvUelfRuZ_AGwzZr/images/nodes/logic.png?fit=max&auto=format&n=RvUelfRuZ_AGwzZr&q=85&s=d1ac1d944599dbdcf174942a34474c60" alt="Logic" width="821" height="902" data-path="images/nodes/logic.png" />

## Configuration

### Code

The **Code** field accepts **JavaScript or TypeScript**.

You can reference outputs from previous nodes using **dynamic values**.

> Tip: Type `{{` to insert dynamic values from earlier nodes.

***

## Writing Logic Code

Your code runs in a **secure sandboxed environment**.

You can:

* Declare variables
* Perform calculations
* Create objects and arrays
* Return a value

### Example: Transform input data

```ts theme={null}
const title = {{parameters.title}};
const description = {{parameters.description}};

return {
  title: title.trim(),
  description: description.trim(),
  createdAt: new Date().toISOString()
};
```

## Using Dynamic Values

Dynamic values are injected using the `{{ }}` syntax.

They can come from:

* Request Parameters Node
* Condition Node
* Database Node
* JWT Node

Example:

```typescript theme={null}
const userId = {{params.userId}};
```

***

## Returning Data

The **return value** of the Logic Node becomes its output.

This output is available to all downstream nodes.

### Example return value

```typescript theme={null}
{
  "total": 1200,
  "discountApplied": true
}
```

***

## Execution Rules

* Code must return a value
* Execution is synchronous
* Errors thrown will stop workflow execution
* Only supported JavaScript/TypeScript features are allowed

***

## Common Use Cases

* Data normalization
* Aggregations
* Conditional transformations
* Building response objects
* Preparing database payloads

***

## Error Handling

If your code:

* Throws an error
* Returns `undefined`

The workflow fails and an error response is returned.