{"version":"2.1.271","anchor":"agent-spawn-now-threads-outputfilereadable-based-on-session","canonical_anchor":"agent-spawn-now-threads-outputfilereadable-based-on-session","heading":"Agent spawn now tracks whether a background output file can be read back","tier":"internal","area":"Subagents","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.271\/e\/agent-spawn-now-threads-outputfilereadable-based-on-session","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.271","markdown":"### Agent spawn now tracks whether a background output file can be read back\n\nSpawned agents and subagents now carry an outputFileReadable flag based on which tools the session has available\n\n**Unclear.** The finding does not say what condition on session tools makes outputFileReadable true or false, or what breaks if it is set wrong.\n\n**What**\n\nAgent-spawn call sites now pass a new `outputFileReadable` field, computed from the session's available tool options, when creating a spawned agent or subagent task. A related caller also sets `outputFileUnreadable: true` when a corresponding flag is false. This is new state that did not exist before.\n\n**Why**\n\nThis lets Claude Code know upfront whether a spawned agent's background output file can be read back later, rather than discovering it only when the read is attempted.\n\n- Area: Subagents\n- Tier: Under the hood\n- Useful: 1\/5\n- Signal: 1\/5"}