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Articles Corridor Reentry

by handel.halowerk.com in News & content

x402 APIPassing, checked 51 min ago

Notify when a previously out-of-range price returns inside a defined corridor. Uses an optional predicate extension of the proven Price-Callback motor. price_corridor_reentry_decision records this exact rule; the rule executes BEFORE dispatch. Same public IPv4HTTPS pinned connections, robots checks,9s,1MiBHTML,at-most-once receipt/idempotency7days,failureschargedfalse. Caller supplies historical price and schedules polling.

POST
https://handel.halowerk.com/v1/price/articles/corridor-reentry
Price
$0.007
per call in USDC
Uptime
100%
last 30 days
Response time
204 ms
416 ms slowest 5%
Last check
Passed
51 min ago, next any minute now

Run a free test callHow to call it

Reliability

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

How to call it

POST https://handel.halowerk.com/v1/price/articles/corridor-reentry

Each call costs $0.007 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://handel.halowerk.com/v1/price/articles/corridor-reentry
content-type: application/json

{
  "callback_url": "https://stack.halowerk.com/_top10-endspurt/callback",
  "ceiling_price": 55,
  "floor_price": 50,
  "idempotency_key": "example_replace_with_random_32_character_key",
  "previous": {
    "currency": "GBP",
    "value": 60
  },
  "url": "https://books.toscrape.com/catalogue/a-light-in-the-attic_1000/index.html"
}

Parameters

ParameterTypeRequiredDescription
callback_urlstringYes
ceiling_pricenumberYes
floor_pricenumberYes
idempotency_keystringYes
previousobjectYes
urlstringYes

Example response

The listing has no example response.

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.007.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://handel.halowerk.com/v1/price/articles/corridor-reentry' \
  -H 'content-type: application/json' \
  --data-raw '{"callback_url":"https://stack.halowerk.com/_top10-endspurt/callback","ceiling_price":55,"floor_price":50,"idempotency_key":"example_replace_with_random_32_character_key","previous":{"currency":"GBP","value":60},"url":"https://books.toscrape.com/catalogue/a-light-in-the-attic_1000/index.html"}'

# 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://handel.halowerk.com/v1/price/articles/corridor-reentry' \
  -H 'content-type: application/json' \
  --data-raw '{"callback_url":"https://stack.halowerk.com/_top10-endspurt/callback","ceiling_price":55,"floor_price":50,"idempotency_key":"example_replace_with_random_32_character_key","previous":{"currency":"GBP","value":60},"url":"https://books.toscrape.com/catalogue/a-light-in-the-attic_1000/index.html"}' \
  | 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 $0.007 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.007" });
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 $0.007 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fhandel.halowerk.com%2Fv1%2Fprice%2Farticles%2Fcorridor-reentry&method=POST
const res = await pay("https://handel.halowerk.com/v1/price/articles/corridor-reentry", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "callback_url": "https://stack.halowerk.com/_top10-endspurt/callback",
    "ceiling_price": 55,
    "floor_price": 50,
    "idempotency_key": "example_replace_with_random_32_character_key",
    "previous": {
      "currency": "GBP",
      "value": 60
    },
    "url": "https://books.toscrape.com/catalogue/a-light-in-the-attic_1000/index.html"
  }),
});
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 $0.007 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.007"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://handel.halowerk.com/v1/price/articles/corridor-reentry",
        json={
            "callback_url": "https://stack.halowerk.com/_top10-endspurt/callback",
            "ceiling_price": 55,
            "floor_price": 50,
            "idempotency_key": "example_replace_with_random_32_character_key",
            "previous": {
                "currency": "GBP",
                "value": 60,
            },
            "url": "https://books.toscrape.com/catalogue/a-light-in-the-attic_1000/index.html",
        },
    )
    print(res.status_code, res.text)

Security scan

No findings

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Recent checks

WhenResultHTTPTimePrice
51 min agoPassed402189 ms$0.007
5 h agoPassed402186 ms$0.007
9 h agoPassed402154 ms$0.007
13 h agoPassed402119 ms$0.007
18 h agoPassed402192 ms$0.007
Show 10 older checks
22 h agoPassed402204 ms$0.007
26 h agoPassed402192 ms$0.007
30 h agoPassed402103 ms$0.007
35 h agoPassed402146 ms$0.007
39 h agoPassed402156 ms$0.007
43 h agoPassed402233 ms$0.007
46 h agoPassed402821 ms$0.007
2 days agoPassed402246 ms$0.007
2 days agoPassed402165 ms$0.007
2 days agoPassed402272 ms$0.007