> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tight.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Custom Data

> Augment Tight API entities with freeform custom data

## Get Started

All Tight API entities have a `customData` parameter. Use this parameter to attach freeform JSON data to Tight API entities.

Custom data can be used to add additional, structured information on an entity. For example, you can add an internal identifier to a Bank Transaction or specialized tax info on a user's General Ledger accounts:

```bash theme={null}
curl -X POST https://sandbox.tight.com/v6/banks/transactions \
-H 'Authorization: Bearer <access_token>' \
-D '[{
        "id": "btn_936723",
        "customData": {
            "internal_key": "some_internal_key",
            "some_other_field": 23434
        }
    }]'
```

<Info>
  `customData` can support up to 50 fields and up to 2000 characters of freeform JSON data
</Info>

Once added, this bank transaction's `customData` will be included anywhere else the transaction can be fetched from the Tight API. For example, the response to the following request includes the `customData` set on this bank transaction:

```bash theme={null}
curl -X GET 'https://sandbox.tight.com/v6/banks/transactions/btn_936723' \
-H 'Authorization: Bearer <access_token>'
```

```json theme={null}
{
    "result": "SUCCESS",
    "data": {
        "id": "btn_936723",
        "type": "REVENUE",
        "amount": 15399,
        "customData": {
            "internal_key": "some_internal_key",
            "some_other_field": 23434
        }
        /* remainder of the properties on this bank transaction */
    },
    "error": []
}
```

<Check>
  The `customData` object now appears in the response, you can leverage this functionality to enhance integrations, reporting, or internal workflows.
</Check>

## Filter on custom data

Coming soon