ToolVet
79trust / 100

Diff

by fetchdelta.com in Search & web

x402 APIPassing, checked 3 h ago

FetchDelta: compare one public web page with its previous stored snapshot. Returns added/removed lines and change previews. The first call creates a baseline; later calls share that URL baseline across buyers. Use page-watch-30d for a private daily watch.

GET
https://fetchdelta.com/api/diff
Price
$0.004
per call in USDC
Uptime
100%
last 30 days
Response time
411 ms
728 ms slowest 5%
Last check
Passed
3 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

GET https://fetchdelta.com/api/diff

Each call costs $0.004 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.

GET https://fetchdelta.com/api/diff?url=https%3A%2F%2Fexample.com%2F

Parameters

ParameterTypeRequiredDescription
urlstring (uri)YesPublic HTTP(S) page URL. No credentials, private hosts or nonstandard ports. JavaScript is not executed.

Example response

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

{
  "addedLines": 0,
  "baselineCreated": true,
  "currentFetchedAt": "2026-09-24T00:00:00.000Z",
  "hasChanges": false,
  "preview": [],
  "previousFetchedAt": null,
  "removedLines": 0,
  "title": "Example Domain",
  "url": "https://example.com/"
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.004.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://fetchdelta.com/api/diff?url=https%3A%2F%2Fexample.com%2F'

# 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 - 'https://fetchdelta.com/api/diff?url=https%3A%2F%2Fexample.com%2F' \
  | 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 $0.004 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.004" });
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 $0.004 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Ffetchdelta.com%2Fapi%2Fdiff
const res = await pay("https://fetchdelta.com/api/diff?url=https%3A%2F%2Fexample.com%2F");
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 $0.004 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.004"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://fetchdelta.com/api/diff?url=https%3A%2F%2Fexample.com%2F")
    print(res.status_code, res.text)

Security scan

No findings

We scan names, descriptions and tool definitions for hidden instructions and other prompt-injection patterns.

Recent checks

WhenResultHTTPTimePrice
3 h agoPassed402305 ms$0.004
8 h agoPassed402368 ms$0.004
12 h agoPassed402486 ms$0.004
17 h agoPassed402613 ms$0.004
22 h agoPassed402386 ms$0.004
Show 10 older checks
26 h agoPassed402411 ms$0.004
31 h agoPassed402355 ms$0.004
35 h agoPassed402656 ms$0.004
39 h agoPassed402524 ms$0.004
43 h agoPassed402462 ms$0.004
2 days agoPassed402338 ms$0.004
2 days agoPassed402474 ms$0.004
2 days agoPassed402562 ms$0.004
3 days agoPassed402543 ms$0.004
3 days agoPassed402480 ms$0.004