# Variables

***

Flowise allow users to create variables that can be used in the nodes. Variables can be Static or Runtime.

### Static

Static variable will be saved with the value specified, and retrieved as it is.

<figure><img src="/files/KtW8JJAzCMyzolCqhBZQ" alt="" width="542"><figcaption></figcaption></figure>

### Runtime

Value of the variable will be fetched from **.env** file using `process.env`

<figure><img src="/files/PzgOnFrkvAH6xBaCJ27q" alt="" width="537"><figcaption></figcaption></figure>

### Override or setting variable through API

In order to override variable value, user must explicitly enable it from the top right button:

**Settings** -> **Configuration** -> **Security** tab:

<figure><img src="/files/GrPorR4buq1s42Io7s3Q" alt=""><figcaption></figcaption></figure>

If there is an existing variable created, variable value provided in the API will override the existing value.

```json
{
    "question": "hello",
    "overrideConfig": {
        "vars": {
            "var": "some-override-value"
        }
    }
}
```

### Using Variables

Variables can be used by the nodes in Flowise. For instance, a variable named **`character`** is created:

<figure><img src="/files/HfDo7afmqgdGwUSqVXGd" alt=""><figcaption></figcaption></figure>

We can then use this variable as **`$vars.<variable-name>`** in the Function of the following nodes:

* [Custom Tool](/integrations/langchain/tools/custom-tool.md)
* [Custom Function](/integrations/utilities/custom-js-function.md)
* [Custom Loader](/integrations/langchain/document-loaders/custom-document-loader.md)
* [If Else](/integrations/utilities/if-else.md)
* Custom MCP

<figure><img src="/files/oXJ5wE2mZOaAfswjRlsc" alt="" width="283"><figcaption></figcaption></figure>

Besides, user can also use the variable in text input of any node with the following format:

**`{{$vars.<variable-name>}}`**

For example, in Agent System Message:

<figure><img src="/files/FSSwKMKoflqkE0E2cpr4" alt="" width="508"><figcaption></figcaption></figure>

In Prompt Template:

<figure><img src="/files/FMhqdNhsYISR6TTplzCk" alt=""><figcaption></figcaption></figure>

## Resources

* [Pass Variables to Function](/integrations/langchain/tools/custom-tool.md#pass-variables-to-function)


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