OpenChainGraph Suite · ART-122 · wave 22

Timestamp Attestation Verifier

Recompute the document integrity anchor, confirm the document hash and timestamp claim match and the algorithm is consistent. Terminal stage of document-integrity-anchor chain.

eIDAS Art.41RFC 3161-alignedW3C VC §13.11Zero PIIClient-side only
🔒 All inputs are processed locally in your browser. No data is transmitted. Do not enter real personal data — use synthetic or anonymised inputs only.
Scope
Verifies a previously created document integrity anchor: recomputes that the presented anchor's document_hash matches the provided document_hash, that the timestamp is consistent, and the algorithm matches. Terminal stage of document-integrity-anchor chain.
Presets
Inputs
Result
Execution Hash & §4 Artifact
SHA-256 execution hash (JCS canonical — RFC 8785):

      

        
    
    
        
        
      

    

  


  
  

    

  







  

    
Ask your agent

    
  

  
Copy this paragraph into Claude, OpenClaw, or any MCP-aware agent to run this exact tool, with this sample, and verify the artifact.

  
Run the AINumbers MCP tool `verify_timestamp_attestation`. Task: Verify document integrity anchor: hash match, timestamp consistency, algorithm match.
Call it with arguments: {"policy_parameters":{"document_hash":"sha256:abcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890","presented_anchor":{"document_hash":"sha256:abcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890","timestamp_claim":{"standard":"eIDAS Art.41 / RFC 3161-aligned","timestamp":"2026-06-25T10:00:00Z","algorithm":"sha256"}},"presented_timestamp":"2026-06-25T10:00:00Z","expected_algorithm":"sha256"}}
Verify before trusting: call `verify_execution_hash` on mcp.ainumbers.co (https://mcp.ainumbers.co/mcp) with the parameter `claimed_hash` set to the returned `execution_hash`, passing the full artifact the run returned (the object containing `policy_parameters` + `output_payload` + `execution_hash`; equivalently `policy_parameters` + `output_payload` with `claimed_hash`), not the bare hash string.
Return the ledger link https://ledger.ainumbers.co/ so a human can re-verify without contacting us.
PII rule: All inputs are processed locally in your browser. No data is transmitted. Do not enter real personal data — use synthetic or anonymised inputs only.
Open the tool with the sample prefilled: https://ainumbers.co/chaingraph/art-122-timestamp-attestation-verifier.html#p=v1.H4sIAAAAAAAA_wGOAXH-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