From a shell

Read-only discovery works from any shell in a Herdr pane:

herdr workspace get "$HERDR_WORKSPACE_ID" | jq -r '.result.workspace.tokens.tower'
herdr pane list --workspace "$HERDR_WORKSPACE_ID" | jq -r '.result.panes[] | select(.tokens.sb_role) | [.pane_id, .tokens.sb_role] | @tsv'
node ~/.pi/agent/npm/node_modules/pi-intercom/cli.mjs ask --to "$TOWER_SESSION_ID" --text "<message>"

Opening a missing tower needs a pi session.