OpenChainGraph Suite · ART-121 · wave 22

Document Integrity & eIDAS Electronic Timestamp Anchor

Bind a document SHA-256 and claimed timestamp into an OCG execution_hash that serves as an eIDAS Art.41 / RFC 3161-aligned electronic timestamp. Feeds timestamp attestation verifier (art-122).

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
Anchors a document hash (sha256:...) and claimed timestamp to produce an OCG execution_hash usable as an eIDAS Art.41-aligned electronic timestamp — no external TSA call. Optionally accepts a C2PA manifest field. Exports W3C VC via §13.11.
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 `anchor_document_integrity`. Task: Bind document SHA-256 + claimed timestamp as eIDAS Art.41 / RFC 3161-aligned electronic timestamp.
Call it with arguments: {"policy_parameters":{"document_hash":"sha256:abcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890","claimed_timestamp":"2026-06-25T10:00:00Z","hash_algorithm":"sha256","document_type":"contract"}}
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-121-document-integrity-anchor.html#p=v1.H4sIAAAAAAAA_wG7AET_eyJkb2N1bWVudF9oYXNoIjoic2hhMjU2OmFiY2RlZjEyMzQ1Njc4OTBhYmNkZWYxMjM0NTY3ODkwYWJjZGVmMTIzNDU2Nzg5MGFiY2RlZjEyMzQ1Njc4OTAiLCJjbGFpbWVkX3RpbWVzdGFtcCI6IjIwMjYtMDYtMjVUMTA6MDA6MDBaIiwiaGFzaF9hbGdvcml0aG0iOiJzaGEyNTYiLCJkb2N1bWVudF90eXBlIjoiY29udHJhY3QifdQxwhm7AAAA