{
  "date": "2026-10-29",
  "operator": "Fixed Agent-written ego-browser v2.2.0 script; no autonomous model benchmark",
  "question": "Does Browserbase authenticated Fetch render JavaScript or write cookie changes back to the saved Context?",
  "early": {
    "source": "https://www.browserbase.com/changelog/authenticated-fetch",
    "title": "Authenticated Fetch | Browserbase",
    "body_text_characters": 0,
    "body_text_sha256": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
    "record_saved_at_utc": "2026-10-29T13:09:12.377249+00:00"
  },
  "later": {
    "source": "https://www.browserbase.com/changelog/authenticated-fetch",
    "title": "Authenticated Fetch | Browserbase",
    "body_text_characters": 1473,
    "body_text_sha256": "ea791271edbb33c5684b5ceb00ae1a115267285c1bbc5cbdf2f0919ef226c1cc",
    "record_saved_at_utc": "2026-10-29T13:10:36.119580+00:00"
  },
  "later_read_condition": "After navigation, wait for document.body.innerText.trim().length > 400, with a 12000ms bound, then extract text.",
  "supported_answer": {
    "fetch_writes_cookies_back": false,
    "javascript_dependent_pages_need_browser_session": true
  },
  "limits": [
    "Two observations of the same public URL, not a controlled rendering experiment.",
    "Cause of the initial empty extraction was not established.",
    "No private account, paid Fetch request, exploit, model run, speed or failure-frequency measurement.",
    "Text hashes identify the recorded extraction and may change when the source is updated."
  ]
}