{"version":"2.1.285","anchor":"session-start-timing-phases-and-new-startup-timing-metrics","canonical_anchor":"session-start-timing-phases-and-new-startup-timing-metrics","heading":"More detailed timing of session startup","tier":"internal","area":"Startup","url":"https:\/\/changelogs.core-directive.com\/v\/2.1.285\/e\/session-start-timing-phases-and-new-startup-timing-metrics","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.285","markdown":"### More detailed timing of session startup\n\nClaude Code now measures how long each part of starting a session takes, for internal diagnostics\n\n**Unclear.** Where these timings are sent is not known.\n\n**What**\n\nClaude Code now times named stages of starting up and running a turn, such as setting up the engine and waiting for MCP servers, the separate programs that add tools. It also adds timings for choosing a model and for waiting on hooks, which are your own commands that run at set points.\n\n**Why**\n\nThis is internal measurement with no direct effect on how Claude Code behaves.\n\n- Area: Startup\n- Tier: Under the hood\n- Useful: 1\/5\n- Signal: 1\/5"}