1 · Reports
Sealed and anchored to Bitcoin
Each report’s measurements are hashed; each day’s hashes become one root, committed to a Bitcoin block through OpenTimestamps.
Proves the report existed in exactly this form by that day.
Proof an agent can check without trusting us.
An agent that acts on what CrawlCheck measured should not have to take our word for it. Every report is fingerprinted and each day anchored to Bitcoin; every answer an agent acts on is signed; every signed answer is entered in a log that a witness running outside our servers re-checks. Each of the three is checked on the reader’s own machine.
Proves
A report with this digest existed in exactly this form by that day, and has not been edited since.
Does not prove
That the measurement was correct. Only the first claim can be settled by mathematics.
64
sealed days
172
reports under this root
#969,655
bitcoin block
Three proofs
What each record proves, and how to check it
Each check runs on the reader’s own machine, from files that are published and can be kept.
2 · Answers
Signed with Ed25519
Every Resolve answer an agent receives before it reads, cites, connects or transacts carries a signature over its canonical content.
Proves the answer came from CrawlCheck and was not altered in transit or afterwards.
3 · History
Logged, chained and witnessed
Every signed answer names its leaf in an append-only Merkle log. Each signed tree head chains to the one before, and a witness running on GitHub, outside our servers, re-checks and co-signs it.
Proves an answer was not rewritten or removed after it was logged.
Method
How a report becomes a proof
No wallet, no fee, no key held by us. The proof is a file, not a coin.
- 1
Measurements only
Host, timestamp, section scores, every path and status fetched, every crawler identity and what it received, the citation state. Wording and layout are excluded, so an editorial change never breaks a proof.
- 2
One digest
Canonicalised with sorted keys and hashed with SHA-256.
- 3
One root a day
Digests sorted and folded into a Merkle tree:
parent = SHA256(left || right), an odd node paired with itself. Arrival order cannot change the root. - 4
Anchored
The root goes to the OpenTimestamps calendars, which commit it into a Bitcoin transaction.
The seal
2026-10-02
Confirmed in Bitcoin block #969,655.
- Merkle root
ba9538312ed78568dc83018ca5888a86b6066fbb5c5619828eb0dd97daee24f6- Reports covered
- 172
- Sealed
- 2026-10-03T01:17:55.830Z
- Calendars
https://a.pool.opentimestamps.orghttps://b.pool.opentimestamps.org- Bitcoin
- block #969,655
Download the .ots proofOne report’s receipt as a single file →
Verify it yourself
ots verify -d ba9538312ed78568dc83018ca5888a86b6066fbb5c5619828eb0dd97daee24f6 crawlcheck-2026-10-02.otsThe reference client checks the file against a Bitcoin node or a public calendar. No CrawlCheck server is needed, or trusted. A fresh seal reads pending confirmation until the next Bitcoin transaction confirms; ots upgrade then stores the block attestation in the file for good.
Ledger
Every sealed day
64 days anchored. Each links to its own root and proof file. Days are sealed once and never recomputed.
- 2026-10-15.ots
- 2026-10-14.ots
- 2026-10-13.ots
- 2026-10-12.ots
- 2026-10-11.ots
- 2026-10-10.ots
- 2026-10-09.ots
- 2026-10-08.ots
- 2026-10-07.ots
- 2026-10-06.ots
- 2026-10-05.ots
- 2026-10-04.ots
- 2026-10-03.ots
- 2026-10-02.ots
- 2026-10-01.ots
- 2026-09-30.ots
- 2026-09-29.ots
- 2026-09-28.ots
- 2026-09-27.ots
- 2026-09-26.ots
- 2026-09-25.ots
- 2026-09-24.ots
- 2026-09-23.ots
- 2026-09-22.ots
- 2026-09-21.ots
- 2026-09-20.ots
- 2026-09-19.ots
- 2026-09-18.ots
- 2026-09-17.ots
- 2026-09-16.ots
- 2026-09-15.ots
- 2026-09-14.ots
- 2026-09-13.ots
- 2026-09-12.ots
- 2026-09-11.ots
- 2026-09-10.ots
- 2026-09-09.ots
- 2026-09-08.ots
- 2026-09-07.ots
- 2026-09-06.ots
- 2026-09-05.ots
- 2026-09-04.ots
- 2026-09-03.ots
- 2026-09-02.ots
- 2026-09-01.ots
- 2026-08-31.ots
- 2026-08-30.ots
- 2026-08-29.ots
- 2026-08-28.ots
- 2026-08-27.ots
- 2026-08-26.ots
- 2026-08-25.ots
- 2026-08-24.ots
- 2026-08-23.ots
- 2026-08-22.ots
- 2026-08-21.ots
- 2026-08-20.ots
- 2026-08-19.ots
- 2026-08-18.ots
- 2026-08-17.ots
- 2026-08-16.ots
- 2026-08-15.ots
- 2026-08-14.ots
- 2026-08-13.ots
The 172 digests sealed under this root
0394a144a773a046b57f655566a0e3d9cf87718d527d9578aca75a93c9f0c4a1 0488483c41761ba7460495b1df5eec66de9943fc8d68aee6a6009e3449cac51f 050934df2a583e6a1f5d3964bc14820631120a719e8e963f950be07ee7abf0ed 06bdae559ea59dec87d9251475201e87f54df0ea1d331c2166abf6b09d619b3c 072fb8502a0e469d7c5a802b6698da60820630ca16d5c73af78da654d2b2a330 07d3f1190177cb25eaa47baeec3fa11fed1df5aa52bb2a7b8694cdaec6aee287 08c7dfe67f8efdec6e9a36b28b92f77d6508ab95b11642592ba1cb769e37279a 0afcf3cc76c18c976b49bace2c0315703be715933673b0afbb64ed1aec97d362 0c4a92c1681854a2ed61a1059e6e3cab7f8cc8aea932d6ee6d3242809a8ce3d8 0e60cc5853a74711ec30cf613cac0bb56c6cf0b6d40b2487dd0767cfd6022598 0fad987f697367bd2d6db44de90b61eab6319c60742f662986d720c670ba9fe0 0fca1d75a1987f8ad6cdba032a0972f6a093850f77848f9ab24ced3d9ea6c4bf 10813709c7a31f6d624a89bda5ee31977826a3d0fe8ef49e9212d043843d4ac2 109ea0f29608341452cd917d22340980f943401faff7b55b173bf66570aa96db 12e1fd154d53b09dee9a8afb51cf91acc5f6f12364c6ee800bd4f9dd83495be1 15f279a8ca2a8005fc59c958368917ff53fba587bb2c9afe5e5b09e0d1a17d30 18e345e4084fb6de3ede2d69f544d3ed5398c440211535998be0b0730767b393 190386406fea3ab9b1d7a1f8eb31f7c8bc7723e191f86ae702cf7c1bd1429801 1fc4be3d6edcdc682aed6f0b1b49ee56dcf44c1c7b65984e4cc271fbe555f804 220e91ddba2c9c655afbb8c96376be027cb51e24ba3b625d880d4a96ffdbc3c9 238178f9cb938e4ef83d47508df20b0cb7c08b1556f41bfa93bdd5560075c0eb 2450f5050a075fd970fc33145774eca82071b0627a87b2cccb041543af7e1d40 245535b2e59264895abb139efb283190f9254804ce1a77a2567410b59c863743 25270395e9f47d77953d5135d4c24392915c3eaff0315614fe5c99dd599d216c 258f6e40a6178e48c6417ab949f0ad365a92808f1d5615b0d4251cbc2fa25b1c 25e15a2d825fa741a72d34b8ec14ef648f68394506e4226979010c8b43adedfa 27f7ba96027e565e8c5f4f7f5b2794dd81a6d700a705a3bc83490651d5f589de 2ac9c9c7b89a64a4988e62cafb60112f6466438678053845a844d267f5a21b6a 2b079052fb00ea1eef3a11272395ab1b6bd005b7d35840faa600d6c6749bd176 2eccdc08700c41f2945f389726496e2f8cf1586c8c3bf4f878660b668581f672 2ff48001e071b01a0e4a750a0ce5c5c40be0a4a07ab982265e53e6d0235174df 30539fa0dbe48538d9a15f8f00247f2d031ff5886e654a3a21141da665fcc4b3 30d4890aa6717d95623dad3f0fc80dbb4e3ac051b56637d2255a611599a91517 32a1a00051ab8fad1da8f13b4c514f377e22b860348d2d813d1424375102211c 32a516f90c7adcb60d2abe57459906cec991e40d20e410f2a87d7c791b40d84d 362169f12624a7da85c1033aeed1639e4f1752a3955ed0fe9c401109f300386f 37e3787438dadd832fee0c8822031842a932b3c86d725be44b71a2a301a58c51 3aa67ced17c687eea339bd21dc0dee5d6b60c46788c944d67d3e784ecdb0078e 3fb6d6b0d5b1fa559754d116fd64297cb2b459844be0737cf1ffb26807fea6ef 46b54654926900caf85f487164893734c1edb79f989d37b1d1bb48c33a5f1690 47a499db8e8a3acac951eb492de452b99706919e88ee7f235f784c840f8c7113 48f10ed49c50ff5be936b36e034de4af98a42a8416be2b269a423d37b9879162 495e0d85b68ff276f7ae69cd04644dfff7ea0722592aa7d8d74a00bc9a16bff2 49b25586ce4154106a5672558c53c57aac94836b43b0f4b1ab9489e8ea93dadf 4a6d3e5fdf312f6aa3e639c28ad414be958cc04564ad4f334bbda6431ec424da 4b93a0a18fae201caa037231cbdb37998cb397b645627e70ddde60df6f00b01d 4bc7335cd88c6a0788f36c1ffb2efa8686b0082b2b5817fd7b21727e7135e903 52146d328a223fa2745461e5715b2a1daa564ba6ace931f4f8a2a17c91fcceec 527785788eedaaf45ac92b1f1359158f051d3f1e4ff3c4a42cac02c88d104517 52f217fdce9ed307ea1ea0b932bbb1186a28f4a461bab1669367b198da722a1c 534d01c8bb48c5046843d39df726160912b2933c6b6a13571d212352bcaf2aa2 53d795c4c7e1f4cdc2d65ed470c0febbd88ea69ef65c3c2da27683ab2ab8c259 5527c174841ed75b40245f090c40371b271783759a03a89ab255d20def76d3ea 5532aec5c01805340c813c61beb1d5932fa13f9b0a1d8e8cf77898fc9ee55b00 569ef766d510d3d8c9ad1a1bb33731b68e8a0a05e4aabd156279e635fd5d5dde 57eaf9c22273243f250738995812cc445f89a408e8a3a82d3f9b797bb1961dec 58a66a9a6efa3d2cf365b6973793cdae12845f39726375dd36777dd8391fd53f 5c119fa0c478ec06e71d5efc67ecdb5bcff320a01ef3e43b0dc69a84b04875ad 5c8190036ec1046d329e73929b2763cd46315f04994a6616737ba3769b0edb86 5dea0989a7ec40fe52144e160d08b2f59706e5681f4c50d2a963692ebec9629c 5f69dc1ab5dcd870298286648d64b7fe4afcfdbe36e5d6bc82f2a9e63aac8986 603997bc424d24eaac3fd3b4511caeed3da69f81ab1c243b93f5d08b4c2e6d7b 61409a98a8ddde470855363ca76d1e39e138f977c053a3f6dec35d5eb00a1fd7 639b14446a583dc08747a40de6363752b34fe75ab2518715fb17a53504ed02c7 641a102571dac22ef4ef175706d9c88fb2941c57af03c9643faba90901be0d0d 6575056e5e02fbdfbf961c3e7bdd944d1d7eb2a9fad82a977a7d9b832464cc0a 65a47ab9f2d19f2014377449ca135f8d689bead2ba14b8d129be806057885631 66bc51b2fca568c014793da88f52b0c991c3335c936609ab0707ff3b973a1b5c 67363bf0c10dbf64fc1a827c5501717f5096a61fe8df1b8606afb8047c04970b 6b043e29fe58395125af375406b8a0e7cf9b0f5bf939a2d812bcc7d4c2a16364 6bc5dcb9c32a94be91ab6abe2c8918f3d429c8eaf595257766fed9b2d99e7a89 6c27be5c996a782bc84fbb1a2b32122d5eedc8c7904ee2d4e4884eb66347bbb8 6da1151bda16a42d935f2409e0548495d3e61bcefa27dcfc422b93520e581ad2 6e1f20197fff0c7f0caf1cc3908758037f3f3c877aae6ffaa36d815c1ae15f78 6e536dbbb1d36b357f0f4af8a788dc891adf89eed61cc6492997526514bb6082 6ee9ee7d24cb99da71ea05b6313a7ab7475f4a0bc18858b2c5f9d74ba66c29b4 6ff8aa96e3b0547461e57094dd5a44c0e344cdf2913d84b087469d208430dad0 70e64d1f10e99a435504558d3d2eb72b512cbb5cddcfdc3bef8c903a48edd7c5 716ebc7b6997be3dee995dd558b690bcaf9cd59a86b5521f9ce0c89cb289bbda 734ba07638993ff800f3b850dc81df46bb78f35caebe6c3692617f64aa53d8e8 7504c2ab2152d7fc781f234c0f3dcd70bec9dc50dcc41cc118bfebe3dc3134d8 7b9ebb772b09bf2a5e7b125749c44acfaf9165809f4106ca4bc7882fbcd8621b 7ba0a1758b44615a681fa3fefb10c528eb02d79f2aec8d8a99df5424f3881bb8 7e71dca10d7b887bdf0f8faac7b9324e158f2ef9e90087d1b9cee36593e26a2b 7fd0a0417007a1da620961cd41cc788793d5f0553fdc1564ddd4ddcf9f78ca96 82349314cc8c936eaa561f9d33c1e31420fd68e63b36310ac244c7f1158eca67 829000b70acc72bbd14507f5ca87c192a70e001d76327f5e44bc45f9c1b6e5b2 8372133d28991700b087da7d6fa8cd65f3ac7d2f5718ee85b0426f8b5b124d81 8abf116945e4bd33bf9c55d195977ab332998293c2a24bc975b8c2aeba24c331 8fef711edab8cde03c82f8e4d3994055d594355300dd27ff57f6b91ee1b49ea9 904b76a69a5a5d8f00afecddc63cc43dbb30090ae348d2a4cf7baf9bbfbe25f0 914db2517c21c2cceb61a26ebc19e1c24c5014b36276360be532c402060885c3 931205040d01ead4a0026a85aba81c765ce84f1a757cac26318f08f3476557fe 9746de2d6c4465c939f90daf50c20ff21e890194dbb36ddf4b1dec9a503a3af1 9889d34c47b9429b7508dbfb578657b740dfb6356c3c5ceb2c10a09577bfc8de 995a41c422824719afddf0c4c7fd8889965cb6bd05e251207f5c69e442c1b7dd 9a5abccb9083fdb3c886ddc374d39c6ab99c53bb678b4a363420483e14c05c67 9b3a475d836dc22b2f4ee8dc68feaffd454c47518f0cfa3374acae40fae70505 9c8bf05775e9c5cbc8f62dadae11f877d014fc6aa23b668d3770d77aa9517cab 9eaaf258cb180565baa34e5051c2155f1a995446f8425e892429fe5abea2b9b8 9f4f1e2db8f45ae0f562ef0a8a19654067bd022902bb48b5f0572cd4fb0c013d 9f67dfa280442233f97f48a33e0a371881d8d23db35818e8b7fb3255e0a678ef a1a9e2a1a5ced75c2c9783257e56ec80fdda382f18cdf709c9f8e96880c39764 a4622a64404beeb85d82f2ca7785d361ed20838b63c4c1b6cf83fe8fea1e7541 a83c15aa32e6c170a1bf80ae953d6ca32051476477d8f60bba7a3a744effe87f 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Questions about this page
QWhat does the Bitcoin anchor prove?
That a report with exactly this digest existed no later than the anchored block, and that it has not been edited since. It is a proof about time and integrity, not about correctness.
QHow do I verify a report myself?
Download the day’s .ots proof from this page, recompute the report digest from its JSON record, and verify the proof with the OpenTimestamps client against a Bitcoin node or public calendar. No CrawlCheck server is needed for the check.
QWhy exclude wording and layout from the hash?
So an editorial change never invalidates a measurement. Only the measured fields are hashed; the words around them can be improved without the proof breaking.
QWhich days are anchored?
Every sealed day is listed on this page with its digest and proof file. Days are sealed once, after they end, and never recomputed. A day sealed within the last day or so reads as pending in the reference client: the calendar holds the commitment, and the Bitcoin block confirming it is usually mined within 24 hours. The proof file here is upgraded to carry that block header once it exists, so a pending file is a proof waiting on a block, not a missing seal.