Use the createGroup command in the groups namespace to create a new group from a list of players. The player returns a group object with the group ID. This may be an existing group ID if an existing group is a subset of the new group. In this case, Sonos may build the new group by adding new players to the existing group.

The group coordinator is chosen as follows. Sonos looks for existing groups whose members are all among the requested players (playerIds plus the players in areaIds), counting an ungrouped player as a group of one. It builds on the largest such group and keeps its coordinator, preferring the group that contains the first player in playerIds when sizes are equal. If there is no such group, the first player in playerIds becomes the coordinator.