Currently there is no stable Jira Cloud REST API endpoint to retrieve a group by its Group ID:

•  GET /rest/api/3/group — deprecated, could be removed at any time
•  GET /rest/api/3/group/member — stable, but only accepts groupName, not groupId
•  GET /rest/api/3/group/bulk — supports groupId but is marked Experimental, meaning its contract is not guaranteed

Confluence Cloud already has a stable GET /wiki/rest/api/group/{groupId} equivalent, making this a parity gap between the two products.

Use case: App developers need to reliably resolve a Group ID to its group name (e.g. for display purposes, access management, etc.) without relying on deprecated or experimental endpoints.

Request: Promote GET /rest/api/3/group/bulk out of Experimental status, or introduce a new stable GET /rest/api/3/group/{groupId} endpoint to provide parity with Confluence.