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Exhibit402 Certificate Re-Verification
x402
Exhibit402 Certificate Re-Verification is a paid API for AI agents from exhibit402.dylan-caponi.workers.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).
Re-verifies an exhibit402 proof-of-publication certificate by recomputing SHA-256 hashes and checking them against on-chain ERC-721 records, returning a machine-readable verdict with per-check detail.
Price / call$0.02
Success—
StatusUnknown
How this service works
Re-verify any exhibit402 proof-of-publication certificate for $0.02. Pass id = ERC-721 token id, Arweave tx id, or job id. The service re-downloads the permanently stored screenshot and signed manifest, recomputes every SHA-256, and checks them against the manifest and the on-chain record (immutable screenshotSha256, tokenURI, owner). Returns a machine-readable verdict with per-check detail, so an agent can confirm a certificate is genuine without trusting the issuer.
Output
A JSON object with a boolean 'verified' field indicating overall certificate validity, a 'checks' array containing per-check details (hash recomputation results, tokenURI match, owner confirmation), plus metadata fields including token_id, url, tier, and a human-readable note.
Example use cases
Legal evidence authenticity check
“I need to confirm this exhibit402 certificate is genuine before submitting it as evidence — the token id is 187. Can you re-verify it, recompute all the hashes, and tell me if every check passes?”
NFT buyer due diligence
“Before I buy this exhibit402 NFT, can you verify token id 553 is authentic and that the screenshot stored on Arweave actually matches what's on-chain?”
Audit trail for published content
“We archived a website snapshot last month and got job id a3f2c1d4-89ab-4cde-bfea-123456789abc. Can you re-verify the certificate now to confirm the screenshot and manifest haven't been tampered with?”
Technical details
Endpoint
GEThttps://exhibit402.dylan-caponi.workers.dev/verifyWhen to prefer
Use this endpoint when you need to independently validate an exhibit402 proof-of-publication certificate without trusting the original issuer — ideal for legal, compliance, or due-diligence workflows where tamper-evidence and cryptographic auditability of a screenshot record matter. Prefer this over manual inspection when you need a machine-readable verdict with granular per-check detail across hash recomputation, Arweave storage, and ERC-721 on-chain anchoring.
Side effects
- Invalid or non-existent id returns an error or unverified verdict
- Arweave network unavailability causes re-download failure
- On-chain record mismatch results in verified: false with failing check details
- Malformed id format (not digits, 43-char Arweave tx, or UUID) triggers input validation error
- Payment failure (x402 protocol) blocks the request before processing
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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