the402 endpoint detail

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x402.shizu.me notarize

https://x402.shizu.me/notarize

payable

Prove a piece of data existed at a point in time. POST {data} returns its sha256, a recorded timestamp, and an HMAC receipt; GET ?hash= tells you whether and when that hash was first notarized. An agent can hash data but cannot self-certify WHEN it existed to a third party — this is that proof.

We sent a real POST request to this endpoint and it answered 402 with payment requirements we could parse.
Price
$0.002
Network
base
Pay to
0x217e5Fe265EB78b29067bF8324ef03a7D8e167C4
Spec dialect
v2 (declares x402Version 2)
Transport
PAYMENT-REQUIRED header
HTTP method
POST
Response latency
167 ms
Payment options
1 usable of 1
Last checked
2026-08-10T09:13:11.716Z (2d ago)
Category
data

Re-check it yourself:
curl "https://api.the402.dev/validate?url=https%3A%2F%2Fx402.shizu.me%2Fnotarize"