Update User Group Members

import { WebClient } from "@slack/web-api"

export type DynSelect_usergroup = string

// Dropdown of the workspace's user groups; needs usergroups:read.

export async function usergroup(auth: RT.Slack) {

  if (!auth?.token) return []

  const { usergroups } = await new WebClient(auth.token).usergroups.list()

  return (usergroups ?? []).map((g) => ({

    value: g.id!,

    label: `@${g.handle} (${g.name})`,

  }))

}

/**

 * Update User Group Members

 * Replace the full member list of a user group (e.g. @oncall) with the given user IDs — users not listed are removed. Workspace settings decide who may edit user groups; a bot token often gets permission_denied, so use a user token from someone allowed to. Requires usergroups:write on the connection (and usergroups:read for the group dropdown).

 */

export async function main(

  auth: RT.Slack,

  usergroup: DynSelect_usergroup,

  users: string[]

) {

  const client = new WebClient(auth.token)

  return await client.usergroups.users.update({

    usergroup,

    users: users.join(","),

  })

}