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

# Variables Node (Set Variable)

> Create, store, and transform values to reuse at any point in the workflow via {{ $vars.name }}.

<Note>
  Variables defined in this node exist only during the current execution. They do not persist between separate runs of the same workflow.
</Note>

## How It Works

The **Set Variable** node creates or overwrites variables scoped to the current execution. Once defined, they are accessible in all downstream nodes via `{{ $vars.variable_name }}` — including condition nodes, HTTP nodes, JavaScript code nodes, and the LLM node prompt.

Use the node to:

* Extract fields from a large payload and give them clear, short names
* Calculate or concatenate values derived from multiple flow sources
* Store intermediate results that will be consumed by more than one downstream node
* Initialize counters, flags, or control objects before entering a loop

## Configuration Options

A single node can define as many variables as needed. Each variable requires three fields:

* **Name** — snake\_case identifier with no spaces; after typing, the panel displays the access expression `{{ $vars.your_name }}`
* **Type** — determines how the value is stored and interpreted by the execution engine
* **Value** — static field, dynamic reference via `{{ }}` template, or block editor for JSON

| Type         | When to use                                                     |
| ------------ | --------------------------------------------------------------- |
| `string`     | Text, IDs, names, emails, alphanumeric values                   |
| `number`     | Quantities, totals, indices for calculations and comparisons    |
| `boolean`    | Control flags (`true` / `false`) for conditionals               |
| `json`       | Complex objects or arrays to be passed to the HTTP or LLM node  |
| `expression` | Full dynamic template — the entire value is resolved at runtime |

## Common Use Cases

The Set Variable node is most useful in the following patterns:

* **Rename payload fields** — an external webhook arrives with keys in a different language or format (`customer.full_name`, `order.ref`); define variables with clearer names before referencing them in downstream nodes, making the flow more readable
* **Build an HTTP request body** — assemble a complex `json` object with fields from different parts of the flow (`$trigger`, `$json`, other `$vars`) and reference the variable as `{{ $vars.payload }}` in the HTTP node's body field
* **Control loop iterations** — initialize `counter` as a `number` with value `0` and `error_list` as `json` with value `[]` before the Loop node; the internal JavaScript node updates these values on each iteration using `vars.counter` and `vars.error_list`