ua-tracer by Paul Kinlan

trace rSYRDc9C

ua-tracer

what does a user agent actually fetch, follow & run?

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Trace rSYRDc9C

First seen: 2026-10-08 13:55:32.361 UTC
User-Agent: http.rb/5.1.1 (Mastodon/4.2.10; +https://toot.thoughtworks.com/) Bot
Bot verification: Not a known bot (no IP-range check applies).

What this user agent did

Directly-referenced assets:

✗ fetched CSS ✗ fetched JS ✗ fetched image ✗ fetched font (HTML)

Document-level link hints:

✗ fetched favicon ✗ fetched apple-touch-icon ✗ fetched web manifest ✗ fetched preload ✗ fetched prefetch

Second-level follows (proves it parsed the linking file):

✗ followed CSS background-image ✗ followed CSS @font-face ✗ followed manifest icon ✗ followed CSS @import

Frames (does it descend into iframes?):

✗ fetched iframe document ✗ descended into iframe (loaded inner image)

Reporting (a report-only CSP is violated by inline styles; reports can arrive via HTTP headers with no JS, or via in-page beacons):

✗ sent a CSP/Reporting report (any path) ✗ delivered via report-uri/Report-To header (no JS) ✗ delivered via in-page beacon (securitypolicyviolation / ReportingObserver)

Social embed (Open Graph / Twitter card images):

✓ fetched og:image ✗ fetched twitter:image

JavaScript execution:

✗ EXECUTED classic JS ✗ EXECUTED ES module ✗ posted client timing

Server-side request waterfall

Every request the server received for this trace, in receive order. +ms is the delta from the homepage request.

ReceivedΔKindMethodUser-Agent
2026-10-08 13:55:32.361 UTC +0 ms homepage GET http.rb/5.1.1 (Mastodon/4.2.10; +https://toot.thoughtworks.com/) Bot
request headers (11) 
{
  "accept": "text/html",
  "accept-encoding": "gzip",
  "connection": "close",
  "date": "Thu, 08 Oct 2026 13:55:32 GMT",
  "host": "uatracer.com",
  "traceparent": "00-fd1c79b823c67af63e04b1e604a8c19e-91369b9d820e5440-01",
  "tracestate": "",
  "user-agent": "http.rb/5.1.1 (Mastodon/4.2.10; +https://toot.thoughtworks.com/) Bot",
  "via": "HTTP/1.1 ams.vultr.prod.deno-cluster.net",
  "x-deno-userspace-traceparent": "00-fd1c79b823c67af63e04b1e604a8c19e-ece5e8f52d6b6559-01",
  "x-deno-userspace-tracestate": ""
}
2026-10-08 13:55:35.651 UTC +3290 ms Open Graph image GET http.rb/5.1.1 (Mastodon/4.2.10; +https://toot.thoughtworks.com/)
request headers (10) 
{
  "accept-encoding": "gzip",
  "connection": "close",
  "date": "Thu, 08 Oct 2026 13:55:35 GMT",
  "host": "uatracer.com",
  "traceparent": "00-69a7061f307cc24abd31f88a23728731-852043d47b7ddd0a-01",
  "tracestate": "",
  "user-agent": "http.rb/5.1.1 (Mastodon/4.2.10; +https://toot.thoughtworks.com/)",
  "via": "HTTP/1.1 ams.vultr.prod.deno-cluster.net",
  "x-deno-userspace-traceparent": "00-69a7061f307cc24abd31f88a23728731-935a581fdcbfd823-01",
  "x-deno-userspace-tracestate": ""
}