Joost Klein
type: MusicGroup
description: Joost Klein (; born 10 November 1997), also known mononymously as Joost or eenhoornjoost, is a Dutch musician, rapper, singer, and former YouTuber. Mainly a hip hop artist, his songs and performances
popularity: 14
followers: 370
additional property: CopyrightID
additional property: CopyrightChainExplorerURL
  type: PropertyValue
  value: https://explorer.copyrightchains.com/tx/0x64439e0c1997b93ca8f83de535fecad1e537214c01c64634a2ebaf9109510345
additional property: OTSHash
additional property: OTSBitcoinBlock
  type: PropertyValue
  value: 953750
additional property: OTSBitcoinBlockVerifyURL
  type: PropertyValue
  value: https://blockstream.info/api/block-height/953750
additional property: OTSProofURL
  type: PropertyValue
  value: https://artists.proofprofile.net/proofs/artist/a74be866-cf31-45f5-8d0e-0121f07260b2.ots
additional property: OTSRecordURL
  type: PropertyValue
  value: https://artists.proofprofile.net/proofs/artist/a74be866-cf31-45f5-8d0e-0121f07260b2.json
additional property: OTSVerificationAPI
  type: PropertyValue
  value: https://artists.proofprofile.net/api/v1/bot/ots/verify/artist/a74be866-cf31-45f5-8d0e-0121f07260b2
additional property: OTSTimestamp
  type: PropertyValue
  value: 2026-06-15T06:12:23Z
additional property: OTSCanonicalRecord
  type: PropertyValue
  value: {"copyright_id":"0x64439e0c1997b93ca8f83de535fecad1e537214c01c64634a2ebaf9109510345","name":"Joost Klein","registered_at":"2026-06-14T22:00:47Z","symbol":"NIM0589515","token_address":"0x04d0c29300e9d6af0e5d6dce24ff766a132981cc","type":"artist","uuid":"a74be866-cf31-45f5-8d0e-0121f07260b2"}
additional property: OTSVerifyInstructions
  type: PropertyValue
  value: 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
subject of: OpenTimestamps Proof of Existence
  type: DigitalDocument
  encoding format: application/vnd.opentimestamps.ots
  description: Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x64439e0c1997b93ca8f83de535fecad1e537214c01c64634a2ebaf9109510345. Chain 2 (Bitcoin): anchored in block 953778 (2026-06-15T11:57:35Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/a74be866-cf31-45f5-8d0e-0121f07260b2.json and https://artists.proofprofile.net/proofs/artist/a74be866-cf31-45f5-8d0e-0121f07260b2.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
  date published: 2026-06-15T11:57:35Z
  text: {"copyright_id":"0x64439e0c1997b93ca8f83de535fecad1e537214c01c64634a2ebaf9109510345","name":"Joost Klein","registered_at":"2026-06-14T22:00:47Z","symbol":"NIM0589515","token_address":"0x04d0c29300e9d6af0e5d6dce24ff766a132981cc","type":"artist","uuid":"a74be866-cf31-45f5-8d0e-0121f07260b2"}