> ## Documentation Index
> Fetch the complete documentation index at: https://docs-dev-fix-docs-5525.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

> Learn how to manage user and app metadata with the Auth0 Lock library.

# Manage Metadata with Lock

You can use the [Lock library](/docs/libraries/lock) to define, add, read, and update the `user_metadata.` You can read the user's `user_metadata` properties the same way you would read any other user profile property. For example, the following code snippet retrieves the value associated with `user_metadata.hobby` and assigns it to an element on the page:

```javascript lines theme={null}
// Use the accessToken acquired upon authentication to call getUserInfo
lock.getUserInfo(accessToken, function(error, profile) {
  if (!error) {
    document.getElementById('hobby').textContent = profile.user_metadata.hobby;
  }
});
```

You can use `additionalSignUpFields` to add custom fields to user sign-up forms. When a user adds data in a custom field, Auth0 stores entered values in that user's `user_metadata`. To learn more about adding `user_metadata` on signup, read [Additional Signup Fields](/docs/libraries/lock/lock-configuration#additionalsignupfields-array-).

## Learn more

* [Lock for Web](/docs/libraries/lock)
* [Lock API Reference](/docs/libraries/lock/lock-api-reference)