AI Crawl Ledger t.co t.co: what it tells AI crawlers
On 27 October 2026, t.co's robots.txt fully blocked 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://t.co/robots.txt unchanged since 2026-10-26 · sha256 1f4a1996aeeb85d3… · view as recorded
The * group blocks applies to every agent without its own group
Per AI bot, 2026-10-27
Other signals
Publishes /llms.txt not observed Publishes /ai.txt not observed Publishes /.well-known/tdmrep.json not observed Reserves TDM rights (TDMRep file, header or meta) not observed Declares Content Signals (robots.txt or header) not observed Says ai-train=no in a Content Signal not observed Points to an RSL licence (robots.txt License line or Link header) not observed Answers with an x402 payment offer (lower bound: only the homepage is probed) not observed Answers HTTP 402 Payment Required (lower bound: only the homepage is probed) not observed Sends noai / noimageai directives not observed Refused our fetcher (403 / challenge) no
robots.txt versions
From Through State Version
2026-10-26 2026-10-27 ok 200 1f4a1996aeeb
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
2024-09-16 CC-MAIN-2024-38 www.t.co server-error unknown unknown unknown unknown unknown unknown unknown 2023-10-02 CC-MAIN-2023-40 www.t.co absent allows allows unknown allows allows unknown allows 2022-10-03 CC-MAIN-2022-40 www.t.co absent allows allows unknown allows allows unknown allows 2021-09-27 CC-MAIN-2021-39 www.t.co absent allows allows unknown allows allows unknown allows 2019-09-23 CC-MAIN-2019-39 www.t.co absent allows allows unknown allows allows unknown allows 2017-09-25 CC-MAIN-2017-39 t.co ok view blocks blocks unknown blocks blocks unknown blocks 2017-01-23 CC-MAIN-2017-04 t.co ok view blocks blocks unknown blocks blocks unknown blocks 2016-10-03 CC-MAIN-2016-40 t.co ok view blocks blocks unknown blocks blocks unknown blocks 2016-09-05 CC-MAIN-2016-36 t.co ok view blocks blocks unknown blocks blocks unknown blocks
Evidence
Every daily observation of t.co 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/t.co