{"version":"2.1.248","anchor":"fleet-view-knows-which-sessions-are-open-in-another-window","canonical_anchor":"fleet-view-knows-which-sessions-are-open-in-another-window","heading":"Fleet view knows which sessions are open in another window","tier":"internal","area":"Background Tasks","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.248\/e\/fleet-view-knows-which-sessions-are-open-in-another-window","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.248","markdown":"### Fleet view knows which sessions are open in another window\n\nThe background-session list tracks which sessions another window is already sitting in.\n\n**What**\n\nThe background-session list now tracks, for each job, whether some other Claude Code window is currently sitting in that session, and uses it to block opening it.\n\n**Details**\n\n- The live-session poll builds a second map of interactive sessions belonging to other processes (kind `interactive`, a different process id, no parked job), stored as `terminalHolders` and read through `terminalHolderOf(job)`.\n- Skipped for peer and remote backends.\n- No flag; always on.\n\n**Evidence**\n\n`terminalHolders`\n\n- Area: Background Tasks\n- Tier: Under the hood\n- Useful: 2\/5\n- Signal: 1\/5"}