> For the complete documentation index, see [llms.txt](https://docs.cosmocloud.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.cosmocloud.io/flow-builder/node-types/variable-nodes/mathematical/add-variable.md).

# Add Variable

**Add Variable** node is designed to perform addition operations and store the result in a specified variable. This node can add a value to an existing variable.

### Properties Panel

| **Field**     | **Description**                                          | **Required** |
| ------------- | -------------------------------------------------------- | ------------ |
| Node name     | [Node Name](/flow-builder/node-name.md)                  | true         |
| Variable Name | The name of the variable where the result will be stored | true         |
| Value         | The value to be added                                    | true         |

### Usage

1. Specify a variable name whose value needs to be fetched and then the result will be stored.
2. Enter the value to be added.

### Behaviour

* If the specified variable doesn't exist, it will raise an error.
* If the variable already exists, the provided value will be added to the current value of the variable.

### Returns

The node stores the result of the addition in the specified variable. You can access this using Magical Autocomplete (e.g., `$.variables.<variable_name>`) in any node below this node.

### Example

Let's say you want to keep a count of processed items:

1. Set Variable name to `$.variables.processed_count`
2. Set Value to `1`

If the value of `processed_count` was `3`, it will now be `4`. If such variable doesn't exist, it'll raise an error.

### Best Practices

* Be aware of the data type of your variables. This node performs numeric addition, so non-numeric values may lead to unexpected results.
* Ensure that the variable is initialised earlier.