{"version":"2.1.281","anchor":"headless-telemetry-init-deferred-and-a-parked-spare-mode","canonical_anchor":"headless-telemetry-init-deferred-and-a-parked-spare-mode","heading":"Headless: telemetry init deferred and a parked-spare mode","tier":"internal","area":"Telemetry","url":"https:\/\/changelogs.core-directive.com\/v\/2.1.281\/e\/headless-telemetry-init-deferred-and-a-parked-spare-mode","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.281","markdown":"### Headless: telemetry init deferred and a parked-spare mode\n\nIn print mode, telemetry setup now waits unless CLAUDE_CODE_ENABLE_TELEMETRY is set, and a new parked-spare state skips session-start hooks\n\n**Unclear.** The finding does not say what a parked spare process is, how one is created, or when the held-back MCP servers are connected.\n\n**What**\n\nIn print mode, where Claude Code handles a request without its interactive screen, telemetry (the collection of usage and performance data) is now set up straight away only when `CLAUDE_CODE_ENABLE_TELEMETRY` is set or one other internal condition holds. Otherwise its setup is deferred through a host callback named `telemetry_init`, and that callback is skipped if the process is shutting down. Other startup housekeeping has moved into a separate `idle_startup_work` callback.\n\nA process can now also be a \"parked spare\" (`spareClaimState() === \"parked\"`). In that state:\n\n- Session-start hooks, which are commands you configure to run when a session begins, are skipped.\n\n- MCP servers (outside tools connected through the Model Context Protocol) configured at neither project nor local scope are held back from the first round of connections.\n\nThe run also now waits on `earlyRemoteLink`.\n\n**Why**\n\nIf you set `CLAUDE_CODE_ENABLE_TELEMETRY`, telemetry still starts immediately. Without it, telemetry setup happens later in the run instead of at startup. If you rely on session-start hooks, note that they do not run while a process is parked.\n\n- Area: Telemetry\n- Names: `CLAUDE_CODE_ENABLE_TELEMETRY`\n- Tier: Under the hood\n- Useful: 2\/5\n- Signal: 2\/5"}