---
title: "Update a custom field"
method: PUT
path: "/v1/custom-fields/{custom_field_id}"
tags: ["Custom Fields"]
---

# Update a custom field

`PUT /v1/custom-fields/{custom_field_id}`

## Request

- Base URL: `https://api.mailrith.com`
- URL: `https://api.mailrith.com/v1/custom-fields/{custom_field_id}`
- Auth: HTTP bearer

Updates a custom-field definition for the authenticated workspace.

## Path parameters

- `custom_field_id` string, required

## Request body

- CustomFieldUpdateRequest
  - `label` string
  - `type` 'Text' | 'Number' | 'Date' | 'Select (Dropdown)' | 'Single Select' | 'Multi Select' | 'Text Area' | 'Checkbox'
  - `settings` object
    - `options` string[]

## Response `200`

Successful response

- object
  - `data` CustomField, required
    - `self` string, required: Stable relative Public API path for retrieving this resource.
    - `id` string, required
    - `label` string, required
    - `type` string, required
    - `settings` object, required
      - `options` string[], required
    - `personalization_token` string, required: The exact ready-to-use token for this custom field. Copy it into an email subject or body text node and replace only the fallback text when needed. This value is computed from the current field label and is not stored separately.
    - `created_at` string, date-time, required
    - `updated_at` string, date-time, required

## Other responses

- `400`: The request is invalid.
- `404`: The custom field was not found.
- `409`: The request conflicts with the current custom field state.

---

[API](https://skmtc.dev/mailrith/apis/mailrith-api.md) · [All operations](https://skmtc.dev/mailrith/apis/mailrith-api/llms.txt) · [OpenAPI document](https://skmtc.dev/mailrith/apis/mailrith-api/revisions/41f09536f2da?raw)