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

# Serialize Values

> Serialize values as strings within transaction metadata limits.

Serialize values as `strings` within [limits](/docs/customize/actions/limitations#transaction-metadata).

<Callout icon="file-lines" color="#0EA5E9" iconType="regular">
  You cannot set values of types: `object` or `array`, but you can serialize as `strings.`
</Callout>

```javascript lines expandable theme={null}
exports.onExecutePostLogin = async (event, api) => {
  const serialized_object_value = JSON.stringify({
    string_value: 'Auth0',
    boolean_value: true,
    number_value: 12
  });

  api.transaction.setMetadata('serialized_object_value', serialized_object_value);

  const serialized_array_value = JSON.stringify([
    'Auth0',
    true,
    12
  ]);
  api.transaction.setMetadata('serialized_array_value', serialized_array_value);

  console.log('serialized_object_value',
    JSON.parse(event.transaction?.metadata?.serialized_object_value)
  );
  /* Outputs "serialized_object_value { string_value: 'Auth0', boolean_value: true, number_value: 12 }" */

  console.log('serialized_array_value',
    JSON.parse(event.transaction?.metadata?.serialized_array_value)
  );
  /* Outputs "serialized_array_value [ 'Auth0', true, 12 ]" */
};
```