Create a custom object field

Platform module

POST/custom-object-fieldscustomObjectFields.create

A typed field of a custom object type. Creates a custom object field. Requires `Idempotency-Key`; a replay returns the original response. The organization is derived from the credential or the parent row, never from the body.

Requires the capability org.custom_objects.write.
OAuth scopes: org.
Send an Idempotency-Key header. A replay with the same key returns the original response.
Error statuses: 400, 401, 409, 422, 429. Errors are RFC 9457 problem details.

Request body: CustomObjectFieldCreate

customObjectFields.create: CustomObjectFieldCreate
Field	Type	Required	Description
custom_object_type_id	string (uuid)	Yes	Identifier of the custom object type.
field_key	string	Yes	Field key.Constraints: pattern ^[A-Za-z0-9][A-Za-z0-9._-]{0,63}$
label	string	Yes	Field label.Constraints: length 1 to 300
data_type	string	Yes	Data type.Constraints: pattern ^[A-Za-z0-9][A-Za-z0-9._-]{0,63}$
required	boolean	No	Whether a value is required.
filterable	boolean	No	Whether the field gets a partial index.
sort_order	integer	Yes	Position in forms and tables.Constraints: range 0 to any

{
  "custom_object_type_id": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f",
  "field_key": "activation_date",
  "label": "Activation Date",
  "data_type": "date",
  "required": false,
  "filterable": true,
  "sort_order": 1
}

Response 201: CustomObjectField

customObjectFields.create: CustomObjectField
Field	Type	Required	Description
id	string (uuid)	Yes	Identifier of the custom object field.
org_id	string (uuid)	Yes	Identifier of the owning organization, derived from the parent row and never accepted from the caller.
created_at	string (date-time)	Yes	When the row was created.
created_by	string (uuid) \| null	Yes	Identifier of the person who created the row; null when a seed, platform or system process created it.
updated_at	string (date-time)	Yes	When the row was last updated.
updated_by	string (uuid) \| null	Yes	Identifier of the person who last updated the row; null when a seed, platform or system process updated it.
custom_object_type_id	string (uuid)	Yes	Identifier of the custom object type.
field_key	string	Yes	Field key.Constraints: pattern ^[A-Za-z0-9][A-Za-z0-9._-]{0,63}$
label	string	Yes	Field label.Constraints: length 1 to 300
data_type	string	Yes	Data type.Constraints: pattern ^[A-Za-z0-9][A-Za-z0-9._-]{0,63}$
required	boolean	Yes	Whether a value is required.
filterable	boolean	Yes	Whether the field gets a partial index.
sort_order	integer	Yes	Position in forms and tables.Constraints: range 0 to any

{
  "id": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f",
  "org_id": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f",
  "created_at": "2026-10-08T14:30:00Z",
  "created_by": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f",
  "updated_at": "2026-10-08T14:30:00Z",
  "updated_by": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f",
  "custom_object_type_id": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f",
  "field_key": "activation_date",
  "label": "Activation Date",
  "data_type": "date",
  "required": false,
  "filterable": true,
  "sort_order": 1
}

Code samples

curl -X POST "$XOS_BASE_URL/custom-object-fields" \
  -H "Authorization: Bearer $XOS_API_KEY" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{"custom_object_type_id":"0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f","field_key":"activation_date","label":"Activation Date","data_type":"date","required":false,"filterable":true,"sort_order":1}'

const { data } = await xos.customObjectFields.create({
    "custom_object_type_id": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f",
    "field_key": "activation_date",
    "label": "Activation Date",
    "data_type": "date",
    "required": false,
    "filterable": true,
    "sort_order": 1
  });

response = xos.custom_object_fields.create({"custom_object_type_id": "0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f", "field_key": "activation_date", "label": "Activation Date", "data_type": "date", "required": False, "filterable": True, "sort_order": 1})

xos custom-object-fields create --data '{"custom_object_type_id":"0192f1e2-7c3a-7b4d-9e8f-1a2b3c4d5e6f","field_key":"activation_date","label":"Activation Date","data_type":"date","required":false,"filterable":true,"sort_order":1}'