...
This endpoint should generate a JSON-Patch file with the differences between the given refs. parent_ref_id and child_ref_id should be either branch_id or commit_id.
PATCH /projects/{project_id}/refs/{parent_ref_id}/
...
diff/{child_ref_id}
This endpoint should accept the JSON-Patch file from the diff endpoint and apply the patch, required in a request body, to the specified ref.
...