> ## Documentation Index
> Fetch the complete documentation index at: https://botpress-ak-docs-20-document-updating-variables-from-outsid.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Update variables outside Studio

You can update [variables](/studio/concepts/variables/overview) outside of [Botpress Studio](/studio/introduction) through an API call.

This is useful for keeping your bot in sync with external data—for example, updating a variable immediately when a user changes their preferences on your website.

<Info>
  You will need:

  * A [published bot](/get-started/quick-start) with at least one variable
  * Basic knowledge of JavaScript/TypeScript
</Info>

## Step 1: Define your Action

First, define an [Action](/studio/concepts/actions) that updates your variable.

<Steps>
  <Step>
    In Studio, go to the <Icon icon="bolt" /> **Actions** section in the left sidebar.
  </Step>

  <Step>
    Select **Create Action** (or **New Action**).
  </Step>

  <Step>
    Select the Action's default name (`New Action`) in the upper-left-corner of the editor, then rename it to `updateVariable`.
  </Step>

  <Step>
    In the code editor, write code that updates the value of your variable to `newValue` and returns an empty object.

    The exact code depends on the name and [scope](/studio/concepts/variables/overview#variable-scopes) of the variable you want to update. For example, if you have a [user variable](/studio/concepts/variables/scopes/user) named `loginEmail`, you would write:

    ```js theme={null}
    user.loginEmail = newValue

    return {}
    ```
  </Step>

  <Step>
    Go to the <Icon icon="braces" /> **Input Schema** section. Then, rename the schema to `UpdateVariableInput`.
  </Step>

  <Step>
    Erase everything in the code editor, then paste in the following code:

    ```js theme={null}
    z.object({
      conversationId: z.string(),
      userId: z.string(),
      newValue: z.string() // Update to your variable's actual data type
    })
    ```

    <Note>
      This code snippet assumes that the [data type](/studio/concepts/variables/overview#data-types-for-variables) of the variable you're updating is a `string`. If your variable uses a different data type, change this to its corresponding [Zod data type](https://zod.dev/api).
    </Note>
  </Step>

  <Step>
    Go to the <Icon icon="braces" /> **Output Schema** section. Rename the schema to `UpdateVariableOutput`.
  </Step>

  <Step>
    Erase everything in the code editor, then paste in the following code:

    ```js theme={null}
    z.object({})
    ```
  </Step>

  <Step>
    Exit the Action editor, then select <Icon icon="rocket" /> **Publish** in the upper-right corner to deploy your changes.
  </Step>
</Steps>

## Step 2: Call your Action using the API

Now, you can call your Action using the Runtime API's [`callAction`](/api-reference/runtime-api/openapi/callAction) endpoint. Just pass in an object that matches the Action's input schema:

<Tabs>
  <Tab title="In an HTTP request">
    ```js theme={null}
    const options = {
      method: 'POST',
      headers: {
        'x-bot-id': 'YOUR_BOT_ID',
        'Content-Type': 'application/json'
      },
      body: JSON.stringify({
        type: 'updateVariable',
        input: {
          conversationId: 'your-conversation-id',
          userId: 'your-user-id',
          newValue: 'your-new-value' // If your variable is a string
        }
      })
    };

    fetch('https://api.botpress.cloud/v1/chat/actions', options)
      .then(res => res.json())
      .then(res => console.log(res))
      .catch(err => console.error(err));
    ```
  </Tab>

  <Tab title="Using the Botpress client">
    ```javascript theme={null}
    import { Client } from '@botpress/client'

    const client = new Client({
      token: 'YOUR_PERSONAL_ACCES_TOKEN',
      botId: 'YOUR_BOT_ID',
    })

    await client.callAction({
      type: 'updateVariable',
      input: {
        conversationId: 'your-conversation-id',
        userId: 'your-user-id',
        newValue: 'your-new-value', /// If your variable is a string
      },
    })
    ```
  </Tab>
</Tabs>

<Check>
  The variable has been updated from outside the Studio.
</Check>