> ## Documentation Index
> Fetch the complete documentation index at: https://terminal49-vorflux-dev-12120-supported-document-types.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Update shipment custom field

> Update an existing custom field value on a shipment in the Terminal49 API, identified by the custom field definition's api_slug for that shipment record.

Updates a specific custom field on a shipment by its `api_slug`.

## Path parameters

| Parameter     | Required | Description                                  |
| ------------- | -------- | -------------------------------------------- |
| `shipment_id` | Yes      | The ID of the shipment                       |
| `api_slug`    | Yes      | The api\_slug of the custom field definition |

## Request body

| Parameter | Required | Description          |
| --------- | -------- | -------------------- |
| `value`   | Yes      | The new value to set |

## Authorization

Requires `update` permission on the shipment.

## Response

Returns `200 OK` with the updated custom field resource on success.