The some objects have a metadata parameter. You can use this parameter to attach key-value data to these objects.
You can specify up to 50 keys, with key names up to 40 characters long and values up to 500 characters long.
Metadata is useful for storing additional, structured information on an object. As an example, you could store your user's full name and corresponding unique identifier from your system.
Do not store any sensitive information (bank account numbers, card details, etc.) as metadata.
Attributes
name string(40)
The name of the custom field.
value string(500)
The value of the custom field.
Example
{
"metadata": [
{
"name": "CUSTOM_FIELD_NAME",
"value": "CUSTOM_FIELD_VALUE"
}
]
}