AI Crawl Ledger loc.gov loc.gov: what it tells AI crawlers
On 27 October 2026, loc.gov's robots.txt allowed all of GPTBot, OAI-SearchBot, ClaudeBot, Claude-SearchBot, Google-Extended, PerplexityBot and CCBot.
Last verified 2026-10-28 03:59 UTC (daily run of 2026-10-27). Proof for that day .
Panel top 1k (Tranco)
robots.txt ok (HTTP 200) · https://www.loc.gov/robots.txt unchanged since 2026-10-26 · sha256 994f1660f526307c… · view as recorded
The * group allows applies to every agent without its own group
Per AI bot, 2026-10-27
Other signals
Publishes /llms.txt no Publishes /ai.txt no Publishes /.well-known/tdmrep.json no Reserves TDM rights (TDMRep file, header or meta) no Declares Content Signals (robots.txt or header) no Says ai-train=no in a Content Signal no Points to an RSL licence (robots.txt License line or Link header) no Answers with an x402 payment offer (lower bound: only the homepage is probed) no Answers HTTP 402 Payment Required (lower bound: only the homepage is probed) no Sends noai / noimageai directives no Refused our fetcher (403 / challenge) no
robots.txt as recorded sha256 5ee4a5774fb6e97b…
User-agent: 008
Disallow: /
#Baiduspider
User-agent: Baiduspider
Disallow: /
User-agent: Baiduspider-image
Disallow: /
User-agent: *
Disallow: /cgi-bin/
Disallow: /web_arch/
Disallow: /rr/mopic/staff
Disallow: /loc/volunteers
Disallow: /ficmanagers
Disallow: /preserv/extranet/
Disallow: /myloc
Disallow: /nationalfilmregistry
Disallow: /fedsearch
Disallow: /search
Crawl-Delay: 5
Sitemap: https://www.loc.gov/sitemap.xml
robots.txt versions
From Through State Version
2026-10-26 2026-10-27 ok 200 994f1660f526
Timeline of changes
Date What changed
No changes since the first observation (2026-10-26).
Reconstructed history (Common Crawl)
From Common Crawl's robots.txt captures: what CCBot was served, one crawl per quarter. A separate series from the daily observations above; a 403 here means Common Crawl was refused, not this ledger.
Crawl Host State GPTBot OAI-SearchBot ChatGPT-User ClaudeBot Claude-SearchBot Claude-User PerplexityBot
2026-09-21 CC-MAIN-2026-39 www.loc.gov ok view allows allows unknown allows allows unknown allows 2025-09-15 CC-MAIN-2025-38 www.loc.gov ok view allows allows unknown allows allows unknown allows 2024-09-16 CC-MAIN-2024-38 loc.gov ok view allows allows unknown allows allows unknown allows 2023-10-02 CC-MAIN-2023-40 loc.gov ok view allows allows unknown allows allows unknown allows 2022-10-03 CC-MAIN-2022-40 loc.gov ok view allows allows unknown allows allows unknown allows 2021-09-27 CC-MAIN-2021-39 loc.gov ok view allows allows unknown allows allows unknown allows 2020-09-28 CC-MAIN-2020-40 loc.gov ok view allows allows unknown allows allows unknown allows 2019-09-23 CC-MAIN-2019-39 loc.gov ok view allows allows unknown allows allows unknown allows 2018-09-24 CC-MAIN-2018-39 loc.gov ok view allows allows unknown allows allows unknown allows 2018-01-29 CC-MAIN-2018-05 loc.gov ok view allows allows unknown allows allows unknown allows 2017-10-23 CC-MAIN-2017-43 loc.gov ok view allows allows unknown allows allows unknown allows 2017-09-25 CC-MAIN-2017-39 loc.gov ok view allows allows unknown allows allows unknown allows 2017-07-24 CC-MAIN-2017-30 loc.gov ok view allows allows unknown allows allows unknown allows 2017-04-24 CC-MAIN-2017-17 loc.gov ok view allows allows unknown allows allows unknown allows 2017-01-23 CC-MAIN-2017-04 loc.gov ok view allows allows unknown allows allows unknown allows 2016-10-03 CC-MAIN-2016-40 loc.gov ok view allows allows unknown allows allows unknown allows 2016-09-05 CC-MAIN-2016-36 loc.gov ok view allows allows unknown allows allows unknown allows
Evidence
Every daily observation of loc.gov is a leaf in that day's Merkle tree. Proof of the robots.txt line for 2026-10-27: audit path (JSON) , day root and OpenTimestamps proof (complete (bitcoin block 973493)).
API: https://infrarabbit.com/crawlers/api/v1/policy/loc.gov