# Create custom object definitions

You can post custom object definitions with the request body schema described below. 

This operation also allows you to use the List custom object definitions response schema as its request schema. If you want to copy all the existing custom objects from an old tenant to a new tenant, you can make a List custom object definitions call in your old tenant and then use its response directly as the request of this operation in the new tenant to import all the custom objects from the old tenant.

The label field is the UI label of the custom object. The object field contains the API Name of the custom object.

### Limitations 

This custom object definition has the following limitations:

* The maximum number of characters for the Custom Object API Name (object) is 64.
* The maximum number of characters for the Custom Object Label (label) is	64.
* The maximum number of characters for the Custom Object Description 250.
* The maximum number of custom fields in an custom object	is 50.
* The maximum number of characters for the custom field API name is	64.
* The maximum number of characters for the custom field label (label) is	64.
* The maximum number of characters for the custom field Description	is 250.
* The maximum number of picklist or multiselect options is 250.
* The maximum length of characters for the Text field is 255.
* The maximum length of characters for the Long Text field is from 256 to 8,192.
* The maximum number of digits to the left of the decimal point for the Number field is 13, and to the right is 9.

Endpoint: POST /objects/definitions/default
Version: 2026-02-20
Security: bearerAuth

## Header parameters:

  - `Accept-Encoding` (string)
    Include the Accept-Encoding: gzip header to compress responses as a gzipped file. It can significantly reduce the bandwidth required for a response. 

If specified, Zuora automatically compresses responses that contain over 1000 bytes of data, and the response contains a Content-Encoding header with the compression algorithm so that your client can decompress it.

  - `Content-Encoding` (string)
    Include the Content-Encoding: gzip header to compress a request. With this header specified, you should upload a gzipped file for the request payload instead of sending the JSON payload.

  - `Zuora-Track-Id` (string)
    A custom identifier for tracing the API call. If you set a value for this header, Zuora returns the same value in the response headers. This header enables you to associate your system process identifiers with Zuora API calls, to assist with troubleshooting in the event of an issue.

The value of this field must use the US-ASCII character set and must not include any of the following characters: colon (:), semicolon (;), double quote ("), and quote (').

  - `Zuora-Entity-Ids` (string)
    An entity ID. If you have Zuora Multi-entity enabled and the OAuth token is valid for more than one entity, you must use this header to specify which entity to perform the operation in. If the OAuth token is only valid for a single entity, or you do not have Zuora Multi-entity enabled, you should not set this header.

  - `Zuora-Org-Ids` (string)
    Comma separated IDs. If you have Zuora Multi-Org enabled, 
you can use this header to specify which orgs to perform the operation in. If you do not have Zuora Multi-Org enabled, you should not set this header.

The IDs must be a sub-set of the user's accessible orgs. If you specify an org that the user does not have access to, the operation fails. This header is important in Multi-Org (MO) setups because it defines the organization context under which the API should operate—mainly used for read access or data visibility filtering. If the header is not set, the operation is performed in scope of the user's accessible orgs.

  - `Zuora-Version` (string)
    API version that determines the response schema. The default version is used if this parameter is not included. Specify Zuora-Version in the request header if you expect a specific response schema.

## Request fields (application/json):

  - `definitions` (object)
    The custom object definitions. This object maps types to custom object definitions.

## Response 200 fields (application/json):

  - `count` (integer)
    The number of objects in the definitions object. The value of this field is the number of custom object definitions in the namespace.

  - `definitions` (object)
    The custom object definitions. This object maps types to custom object definitions.

## Response 400 fields (application/json):

  - `processId` (string)
    The ID of the process that handles the operation.

  - `reasons` (array)
    The container of the error code and message. This field is available only if the success field is false.

  - `reasons.code` (string)
    The error code of response.

  - `reasons.message` (string)
    The detail information of the error response

  - `requestId` (string)
    Unique identifier of the request.

  - `success` (boolean)
    Indicates whether the call succeeded.