ToolVet
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Webhook Signature

by sicher.halowerk.com in Other

x402 APIPassing, checked 2 h ago

Providers each build their signing string differently — some sign only the body, others prepend a timestamp, an id, or a version marker in a fixed order — and getting that order wrong produces a mismatch that looks exactly like an attack. This checks the signature the way the named provider actually specifies, with constant-time comparison, and returns the string that was signed so a mismatch can be debugged instead of guessed at.

POST https://sicher.halowerk.com/v1/webhook-signature

Last 30 days

All checks passedSome failedAll failedNot checked
Uptime
100%
Response time
113 ms typical, 113 ms slowest 5%
Last check
2 h ago
Next check
any minute now

How to call it

# See the payment challenge (nothing is charged)
curl -i -X POST "https://sicher.halowerk.com/v1/webhook-signature" \
  -H "content-type: application/json" \
  -d '{"body":"{\"synthetic\":true,\"event\":\"documentation-example\"}","provider":"github","secret":"HALOWERK-public-synthetic-example-never-use-for-authentication","signature":"sha256=fdfaa7380ce9e369a7d90e8651603bb777a4f008dd3070b056d2b59122d602f8"}'
import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { ExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const client = new x402Client().register(
  "eip155:8453",
  new ExactEvmScheme(privateKeyToAccount(process.env.AGENT_KEY)),
);
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? Preflight it first for $0.005:
// GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fsicher.halowerk.com%2Fv1%2Fwebhook-signature
const res = await pay("https://sicher.halowerk.com/v1/webhook-signature", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({"body":"{\"synthetic\":true,\"event\":\"documentation-example\"}","provider":"github","secret":"HALOWERK-public-synthetic-example-never-use-for-authentication","signature":"sha256=fdfaa7380ce9e369a7d90e8651603bb777a4f008dd3070b056d2b59122d602f8"}),
});
console.log(await res.json());

Example input

{
  "body": "{\"synthetic\":true,\"event\":\"documentation-example\"}",
  "provider": "github",
  "secret": "HALOWERK-public-synthetic-example-never-use-for-authentication",
  "signature": "sha256=fdfaa7380ce9e369a7d90e8651603bb777a4f008dd3070b056d2b59122d602f8"
}

Security scan

  • No findings. We scan names, descriptions and tool definitions for hidden instructions and other prompt-injection patterns.

Recent checks

WhenResultHTTPTimePrice
2 h agoPassed402113 ms$0.002
7 h agoPassed402148 ms$0.002