sigtap-outreach-api.sigtap.workers.dev

Live 402 challenge

Captured by the enrichment pass, not read just now. Prices can change — always read the 402 the endpoint answers with.

{
  "error": "payment_required",
  "how_to_pay": {
    "catalog": "/llms.txt",
    "openapi": "/openapi.json",
    "version": "x402 v2 (scheme \"exact\", network \"eip155:8453\", USDC on Base)",
    "challenge": "base64 JSON in the Payment-Required response header - decode it",
    "easiest_path": "use the official client: npm i x402 (x402/fetch wrapFetchWithPayment handles all of the above)",
    "request_header": "PAYMENT-SIGNATURE: <base64 JSON>",
    "header_json_shape": {
      "payload": {
        "signature": "<EIP-712 TransferWithAuthorization signature, uint256 fields, r|s|v 65-byte hex>",
        "authorization": {
          "to": "<payTo from challenge>",
          "from": "<buyer address>",
          "nonce": "<32-byte hex, fresh per attempt>",
          "value": "<amount from challenge, base units, string>",
          "validAfter": "0",
          "validBefore": "<unix seconds, string>"
        }
      },
      "accepted": "<the decoded challenge object, verbatim>",
      "x402Version": 2
    }
  },
  "free_preview": "https://sigtap-outreach-api.sigtap.workers.dev/preview/tools/domain-age"
}

Accepts

The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.

[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0x963d450CA601d52B5D92a8540Aea8D4272223ae1",
    "amount": "3000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 300
  }
]

Provenance

Seen in the source catalog

2026-09-09 07:46Z

Last indexed by Roundhouse

2026-09-24 07:45Z

Last enriched (probe, favicon, geo)

2026-09-14 20:16Z

x402 version

2

Max timeout

300s

Liveness probe

HTTP 402