exhibit402
Permanently prove what a URL served at a moment in time.
Two independent observers on different networks capture your URL at the same frozen instant; matching captures are CERTIFIED, the evidence is stored permanently, and an ERC-721 certificate carrying every observer hash is minted to the wallet that paid.
How it works
- Two standardized browsers (identical software, pinned by image digest) on Google Cloud and Fly.io, both in Los Angeles but on different networks, load your URL at one shared frozen timestamp.
- Byte-identical captures: tier CERTIFIED. Any difference after one retry round: tier WITNESSED, and the certificate reports the pixel agreement percentage, the differing regions, and a diff map. Both tiers are deliverables; WITNESSED is honest evidence that the page varies per visitor.
- The screenshot and a certificate manifest are stored permanently on Arweave. The manifest records every observer hash, the browser image digest, the frozen timestamp, plus the screenshot's SHA-256 and IPFS CIDv1 so any surviving copy verifies independently, forever.
- An ERC-721 certificate is minted on Base to the wallet that paid. The token URI points at the manifest and can never be repointed; there is no setter, no burn, no upgrade path in the contract.
- Beyond pixels, each observer preserves what the domain served: the redirect chain, response headers, the TLS certificate chain as presented, DNS answers, and the DOM at capture time. The certificate also embeds an RFC 3161 timestamp token from an independent time-stamping authority, verifiable with plain OpenSSL, and references the exact system description version that produced it by SHA-256.
Pricing
POST /capture mode fullpage | $1.00 USDC on Base via x402 |
POST /capture mode viewport | $0.50 (first screen only; immune to randomized below-fold modules) |
GET /claim/{job_id} | free, durable, no expiry |
Policy
- Captures rejected for oversize (PNG above 40MB), pages that never finish loading, or by the content screen (material illegal to distribute, doxxing of private individuals) are refunded automatically minus a disclosed $0.10 processing fee.
- Service faults are refunded in full. WITNESSED results are not refunded; the tier is the deliverable.
- Private and internal addresses are refused before payment.
Evidence-grade by design
The certificate follows the FRE 902(13)/(14) self-authentication model: a documented automated process, hash-based digital identification, and independent corroborating witnesses. Useful for proof of publication, web evidence preservation, and spoliation-proofing. (Evidence-grade design is not legal advice.)