---
title: "Update a project custom field"
method: PATCH
path: "/companies/{company}/projects/{project}/custom-fields/{field}"
tags: ["Projects"]
---

# Update a project custom field

`PATCH /companies/{company}/projects/{project}/custom-fields/{field}`

## Request

- Base URL: `https://api.factuarea.com/v1`
- URL: `https://api.factuarea.com/v1/companies/{company}/projects/{project}/custom-fields/{field}`
- Auth: one of:
  - HTTP bearer
  - API key in header `X-API-Key`

Partially update a custom field definition. Removing an option that tasks still use, or changing the type in a way their values cannot follow, returns 422 `invalid_custom_field_definition`.

## Path parameters

- `company` string, uuid, required
- `project` string, uuid, required
- `field` string, uuid, required

## Headers

- `Idempotency-Key` string
- `Factuarea-Version` string, date

## Request body

- UpdateTaskCustomFieldV1Request
  - `name` string: New name.
  - `type` string: Type: immutable; a value different from the current one returns 422 `invalid_custom_field_definition`.
  - `required` boolean: Whether the field is required.
  - `default_value` union: Default value (text, number, boolean, a `YYYY-MM-DD` date, an option or a list of options); `null` removes it.
    - string
    - number
    - boolean
    - string[]
  - `options` string[], nullable: Complete resulting list of options (up to 100).

## Response `200`

- object
  - `data` ProjectCustomField, required: A custom field defined for the tasks of a project.
    - `id` string, uuid, required: UUID v7 of the custom field.
    - `object` 'project_custom_field', required: Stripe-like discriminator. Always `project_custom_field` for this resource.
    - `project_id` string, uuid, required: UUID of the project.
    - `name` string, required: Field name, unique in the project.
    - `type` 'text' | 'number' | 'date' | 'dropdown' | 'boolean' | 'multiselect', required: Value type of the field.
    - `required` boolean, required: `true` when every task of the project must have a value.
    - `default_value` string, nullable, required: Value given to new tasks, serialized as a string (a JSON array for `multiselect`), or `null`.
    - `options` string[], required: Allowed values for `dropdown` and `multiselect`; empty for the other types.
    - `position` integer, required: Display order of the field.

## Other responses

- `400`: `parameter_unknown` with `subcode` `retired_active_profile_header`: the retired `X-Active-Profile` header was sent; the company goes in the path. `parameter_invalid_format` on `Factuarea-Version`: the header is not a `YYYY-MM-DD` date. `unsupported_api_version`: the `Factuarea-Version` date is not a supported version.
- `401`: Missing or invalid API key.
- `403`: The request is authenticated but not allowed: the API key lacks the required scope (`insufficient_scope`), the plan does not include the public API or this feature (`addon_not_active`, `feature_not_available_in_plan`), or the module is not available with a test key (`module_not_available_in_sandbox`).
- `404`: The requested resource does not exist or belongs to another company.
- `422`: Validation failed. The `error.param` field identifies which input is invalid.
- `429`: Rate limit exceeded. Retry after the duration in `Retry-After`.
- `500`: Unexpected server error.

---

[API](https://skmtc.dev/factuarea/apis/factuarea-public-api.md) · [All operations](https://skmtc.dev/factuarea/apis/factuarea-public-api/llms.txt) · [OpenAPI document](https://skmtc.dev/factuarea/apis/factuarea-public-api/revisions/718e77934422?raw)