Set a Default Value for a Custom Field

To set a default value for a project custom field

1. Get the ID of the project where you want to set the default value. For instructions, see Get a Project ID. This example uses the project Sample Project with the entity ID 0-0.

2. Get the list of custom fields that are attached to the project. Request the field ID, field name, assigned bundle, and current default values.

   curl -X GET 'https://example.youtrack.cloud/api/admin/projects/0-0/customFields?fields=id,field(name),bundle(id,name,values(id,name)),defaultValues(id,name),$type' \ -H 'Accept: application/json' \ -H 'Authorization: Bearer <YouTrack_token>' \ -H 'Content-Type: application/json'

   In the response, locate the custom field and the value that you want to set as default. This example uses the Affected versions field with the entity ID 105-42 and the 2026.1 version value with the entity ID 133-19.

   [ { "field": { "name": "Affected versions", "$type": "CustomField" }, "bundle": { "values": [ { "name": "2026.1", "id": "133-19", "$type": "VersionBundleElement" }, { "name": "2026.2", "id": "133-24", "$type": "VersionBundleElement" } ], "name": "Affected versions", "id": "97-4", "$type": "VersionBundle" }, "defaultValues": [], "id": "105-42", "$type": "VersionProjectCustomField" } ]

3. Set the default value by updating the defaultValues attribute of the project custom field.

   curl -X POST 'https://example.youtrack.cloud/api/admin/projects/0-0/customFields/105-42?fields=id,field(name),defaultValues(id,name)' \ -H 'Accept: application/json' \ -H 'Authorization: Bearer <YouTrack_token>' \ -H 'Content-Type: application/json' \ -d '{ "defaultValues": [ {"id": "133-19", "$type": "VersionBundleElement"} ] }'

   If the request is successful, the response contains the updated project custom field.

   { "field": { "name": "Affected versions", "$type": "CustomField" }, "defaultValues": [ { "name": "2026.1", "id": "133-19", "$type": "VersionBundleElement" } ], "id": "105-42", "$type": "VersionProjectCustomField" }