ToolVet
77trust / 100

Attest

by Web Page Proof (Signed) in Search & web

x402 APIPassing, checked 5 h ago

Signed proof of what a web page said: give a URL, get its text, screenshot and TLS details with a timestamped cryptographic signature anyone can verify.

POST
https://attest.tollkit.dev/attest
Price
$0.05
per call in USDC
Uptime
100%
last 30 days
Response time
333 ms
459 ms slowest 5%
Last check
Passed
5 h ago, next any minute now

Run a free test callHow to call it

Reliability

All checks passedSome failedAll failedNot checked

Status and outage history · Atom feed · Watch with other listings

How to call it

POST https://attest.tollkit.dev/attest

Each call costs $0.05 in USDC on Base, paid with the request over x402.

Run a free test callOne unpaid request, the way an agent sends it. You see the payment challenge it gets back. Nothing is charged.

Example request

From the listing.

POST https://attest.tollkit.dev/attest
content-type: application/json

{
  "url": "https://fly.io/pricing"
}

Parameters

ParameterTypeRequiredDescription
screenshotbooleanNoCapture and hash a screenshot. On by default — an attestation without one is much weaker evidence. Turn it off for a faster, text-only record. Default: true.
urlstring (uri)YesAbsolute https:// URL of the page to attest to. Anything a dispute could turn on: terms of service, a price, a published policy, a competitor's claim, a listing that may be edited later.

Example response

The provider's example. We can't check it without paying.

Example response, 36 lines
{
  "attestation": {
    "algorithm": "EIP-191 personal_sign over keccak256(canonical JSON)",
    "claim": {
      "attestedBy": "0x… (signer address)",
      "capturedAt": "2026-10-04T12:00:00.000Z",
      "finalUrl": "https://fly.io/pricing/",
      "headers": {
        "content-type": "text/html; charset=utf-8"
      },
      "httpStatus": 200,
      "redirected": true,
      "remoteAddress": "IP that served the page",
      "screenshotSha256": "sha256 hex of the screenshot bytes",
      "textLength": 9312,
      "textSha256": "sha256 hex of content.text",
      "title": "Fly.io Pricing",
      "tlsIssuer": "TLS certificate issuer",
      "tlsSubject": "fly.io",
      "tlsValidFrom": "certificate start date",
      "tlsValidTo": "certificate end date",
      "url": "https://fly.io/pricing",
      "version": 1
    },
    "digest": "0x… keccak256 of the canonical claim",
    "signature": "0x… EIP-191 signature over the digest",
    "signer": "0x… (signer address)"
  },
  "content": {
    "screenshotBase64": "/9j/4AAQSkZJRgABAQ… (full JPEG, base64)",
    "screenshotMimeType": "image/jpeg",
    "text": "The page's visible text, exactly as hashed in textSha256…",
    "textTruncated": false
  },
  "verify": "https://attest.tollkit.dev/attest/verify"
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.05.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://attest.tollkit.dev/attest' \
  -H 'content-type: application/json' \
  --data-raw '{"url":"https://fly.io/pricing"}'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - -X POST 'https://attest.tollkit.dev/attest' \
  -H 'content-type: application/json' \
  --data-raw '{"url":"https://fly.io/pricing"}' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode
JavaScript: pay and call
// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.05 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.05" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.05 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fattest.tollkit.dev%2Fattest&method=POST
const res = await pay("https://attest.tollkit.dev/attest", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "url": "https://fly.io/pricing"
  }),
});
console.log(res.status, await res.text());
Python: pay and call
# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.05 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.05"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://attest.tollkit.dev/attest",
        json={
            "url": "https://fly.io/pricing",
        },
    )
    print(res.status_code, res.text)

Security scan

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Recent checks

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