{
  "slug": "performance-start-trace-supports-cold-load-traces-with-ignorecache-77dd8a7e3e06",
  "title": "performance_start_trace supports cold-load traces with ignoreCache",
  "tools": [
    "chrome-devtools-mcp"
  ],
  "tags": [
    "agent"
  ],
  "introduced_at": "2026-10-15T14:01:41.000Z",
  "announced_at": "2026-10-15T14:01:41.000Z",
  "effective_at": null,
  "date_basis": "source-publication",
  "status": "unknown",
  "how": {
    "incantation": "For a cold page-load trace, first navigate to the target URL, then call `performance_start_trace` with `reload: true` and `ignoreCache: true`.",
    "examples": [
      "performance_start_trace({\"pageId\": <pageId>, \"reload\": true, \"ignoreCache\": true})"
    ],
    "gotchas": [
      "Version: 1.11.0",
      "pageId (required): Targets a specific page by ID.",
      "reload: Automatically reloads the target page after tracing starts.",
      "ignoreCache: Bypasses the HTTP cache on reload to measure a cold page load; only applies when `reload` is true.",
      "Prerequisite: Navigate to the target URL with `navigate_page` before starting the trace when `reload` is true.",
      "`ignoreCache` has no effect unless `reload` is true."
    ]
  },
  "why_it_matters": "When measuring a cold page load, start a trace that reloads the page with the HTTP cache bypassed.",
  "before": "Previously, a cold trace required starting the trace without reload, then calling `navigate_page({ignoreCache: true})` separately.",
  "sources": [
    "https://github.com/ChromeDevTools/chrome-devtools-mcp/releases/tag/chrome-devtools-mcp-v1.11.0",
    "https://github.com/ChromeDevTools/chrome-devtools-mcp/pull/2931",
    "https://github.com/ChromeDevTools/chrome-devtools-mcp/blob/3467d40da8f27aecf779ce325549e4b2436761ae/docs/tool-reference.md"
  ],
  "rank": 0.98039,
  "judge": {
    "publish": true,
    "judge_model": "codex-cli/gpt-6-luna+typesafe/jev-1.13.0",
    "prompt_version": "extract-v7+enrich-v2+judge-v2x3+jev-publish-v1"
  },
  "review_state": "approved",
  "provenance": {
    "run_id": "daily-20261015-20",
    "verdict_id": "daily-20261015-20:daily-20261015-20-0fad988eee015972-2:gate",
    "evidence_hash": "f4ab448bcf93bfbc244c11495c3319bca957c64c1a6b2148d3c22048468b33a0"
  },
  "review": {
    "draft_hash": "0e677bd033a0f2731d03fc3798075a4d850c7790e2810715232893bf107febd4",
    "reviewer": "publication-gate",
    "reviewed_at": "2026-10-15T14:01:41.000Z",
    "decision": "daily-20261015-20:gate",
    "reason": "3 of 3 judge runs approved with p_yes >= 0.9 (mean 0.98 >= 0.9; 2 needed) and Jev gave 0.82 (>= 0.6 needed)."
  }
}