{"version":"2.1.10","anchor":"perfetto-performance-tracing-in-development","canonical_anchor":"perfetto-performance-tracing-in-development","heading":"Perfetto Performance Tracing [In Development]","tier":null,"area":null,"scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.10\/e\/perfetto-performance-tracing-in-development","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.10","markdown":"### Perfetto Performance Tracing [In Development]\n\n**What**\n\nInfrastructure for generating Perfetto-compatible trace files to analyze Claude Code performance.\n\n**Status**\n\nFeature-flagged, returns `false`. The `PERFETTO_TRACING` feature gate is disabled.\n\n**Details**\n\n- Set `CLAUDE_CODE_PERFETTO_TRACE=1` or provide a file path to enable (once feature flag is enabled)\n- Traces include API call timing, time-to-first-token (TTFT), token throughput metrics\n- Output in Chrome Trace Event format (`trace-{sessionId}.json`)\n- Tracks per-agent timing with parent-child relationships for nested agent calls\n- Includes metadata like input\/output token counts, cache hit rates, and errors\n\n**Usage** (when enabled):\n\n`CLAUDE_CODE_PERFETTO_TRACE=1 claude # or CLAUDE_CODE_PERFETTO_TRACE=\/path\/to\/trace.json claude` **Evidence** `r_2()` at line 356811 (initialization, checks `process.env.CLAUDE_CODE_PERFETTO_TRACE` but guarded by `ix.PERFETTO_TRACING` which returns `!1`)"}