XPL, for expert's programming language is a programming language based on PL/I, a portable one-pass compiler written in its own language, and a parser generator tool for easily implementing similar c
1. Compute SHA-256 of OTSCanonicalRecord value → must equal OTSHash 2. Open OTSProofURL → extract Bitcoin block number → must equal OTSBitcoinBlock 3. GET OTSBitcoinBlockVerifyURL → returns the Bitcoin block hash at height OTSBitcoinBlock; GET https://blockstream.info/api/block/{that hash} → its timestamp must match OTSTimestamp 4. Read CopyrightID inside OTSCanonicalRecord → must equal the CopyrightID above 5. GET OTSVerificationAPI → pre-computed 6-check result from server 6. If all match: this entity was registered on CopyrightChains at OTSTimestamp, independently verifiable on Bitcoin
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x716207f9aaa24e8ac39129d49224f8862d4b85f593e7fd8e8079ed61b1a0ab0f. Chain 2 (Bitcoin): anchored in block 954066 (2026-06-17T08:11:48Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/5f18f50f-983e-4dfa-8d55-85c0cf9f5a9d.json and https://artists.proofprofile.net/proofs/artist/5f18f50f-983e-4dfa-8d55-85c0cf9f5a9d.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).