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ProofOfAuthenticity by CHECKHC

ProofOfAuthenticity by CHECKHC - Blockchain timestamping with AI detection and C2PA authenticity. Learn more: https://www.checkhc.net

Actions4

Create Certificate

AI-generated

Summary

Create a blockchain certificate via CHECKHC API. Two modes: simple (SHA-256 hash timestamped on Solana, 1 credit, file stays on device) or ai (AI analysis + C2PA metadata, 30 credits). File input via binary from previous node, URL, or base64 string.

Inputs

  • credentialType — Choose which credential to use. Both use the same CHECKHC API. Default: proofOfAuthenticityApi.
  • certificationMode (required) — Select certification mode. Default: simple.
  • inputType — How to provide the file content. Default: binary.
  • binaryPropertyName — Name of the binary property containing the file. Default: data. Shown when inputType is binary.
  • fileUrl (required) — URL of the file to certify. Shown and required when inputType is url.
  • fileData (required) — Base64 encoded file with data URI prefix. Shown and required when inputType is base64.
  • title (required) — Certificate title.
  • author — Author name.
  • description — Certificate description.

Output shape

JSON response from the CHECKHC API, including certificate metadata such as iv_storageid, c2pa_download_url, hash, file_size, and file_type. Mode-dependent: simple returns hash/timestamp metadata; ai returns full certificate details with C2PA-signed PDF URL and authenticity analysis.

Returned as the node's main output JSON data, paired with the input item index.

Examples

Example 1: Simple mode with binary input

credentialType=proofOfAuthenticityApi, certificationMode=simple, inputType=binary, title=Document.pdf. The node calculates SHA-256 hash client-side and posts hash metadata to /api/storage/solmemo/create-hash. Original file remains on device. Costs 1 credit.

Example 2: AI mode with URL input

credentialType=digiCryptoStoreApi, certificationMode=ai, inputType=url, fileUrl=https://example.com/image.jpg, title=Document.pdf. The node validates the URL for SSRF safety, downloads the file (max 10MB), uploads to /api/solmemo/create for AI analysis and C2PA generation. Costs 30 credits. Returns C2PA-signed PDF download URL.

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