# Batch amend entities Custom Data Model membership.

`BatchAmend`

`POST /api/datamodel/$batchamend`

- [OpenAPI fragment](https://www.lusid.com/docs/api/lusid/endpoints/custom-data-models/BatchAmend.json)
- [Rendered page](https://www.lusid.com/docs/api/lusid/endpoints/custom-data-models/BatchAmend)

Add/Remove entities to/from a Custom Data Model in a single operation.
            
Each amendment request must be keyed by a unique correlation ID.  This id is ephemeral and is not stored by LUSID.
It serves only as a way to easily identify each amendment in the response.
            
Note: If using partial failure modes, then it is important to check the response body for failures as any
failures will still return a 200 status code.

## Referenced schemas

- [MembershipAmendmentRequest](https://www.lusid.com/docs/api/lusid/schemas/MembershipAmendmentRequest.txt)
- [BatchAmendCustomDataModelMembershipResponse](https://www.lusid.com/docs/api/lusid/schemas/BatchAmendCustomDataModelMembershipResponse.txt)

[< Custom Data Models](https://www.lusid.com/docs/api/lusid/endpoints/custom-data-models/llms.txt)