Monitoring · x402 · early usage

Use before paying an x402 endpoint you have not used before, when you cannot tell a wor…

by deadchannel.vercel.app · discovered, not yet claimed by its owner · updated 2026-10-10

30d calls3

30d payers3

MethodPOST

Outputjson

Mirrored from Coinbase's public x402 Bazaar. The description is the provider's own text and has not been reviewed here; the payment requirements are copied as published.

What it does

Use before paying an x402 endpoint you have not used before, when you cannot tell a working seller from a trap, a testnet address dressed as mainnet, or a listing whose price no longer matches its challenge. Returns a verdict — live, degraded, trap, testnet or dead — a 0-100 risk score, and the specific findings behind both, so an agent can decline a bad endpoint instead of learning about it by losing the money. Costs less than the smallest payment it protects.

Tags: preflight · payment-guard · x402 · risk · agent-safety · bazaar

Call contract

Method: POST
Input: json
Output: json
Last paid call: 2026-10-10

Input example from Bazaar metadata

{
  "url": "https://api.example.com/paid-endpoint"
}

Output example

{
  "latencyMs": {
    "p50": 180,
    "p99": 240
  },
  "priceUsd": 0.01,
  "problems": [
    {
      "detail": "No input or output schema.",
      "id": "schema-advertised",
      "status": "warn"
    }
  ],
  "risk": 25,
  "url": "https://api.example.com/paid-endpoint",
  "verdict": "degraded"
}

Use with an agent

Discover. Agents find this listing with GET https://bazaar.saylorinnovations.com/discovery/search?query=…, the MCP tool search_resources, or /discovery/resources.
Inspect. Fetch /resources/38709.json for the price and payment options.
Pay. Call GET https://deadchannel.vercel.app/probe. The provider answers 402 with its payment requirements. An x402 client signs one of the options below and retries with PAYMENT-SIGNATURE.
Execute. The provider returns 200 with the data. Agent Bazaar is not in the request path and never sees your payment.

For humans

You don't need an account or an API key; you need a wallet holding a small amount of USDC on Base, algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=, Solana, and an x402-capable client (see the examples below). Call the endpoint unpaid first to see exactly what it asks for.

Pricing & payment

Price: $0.005 / request
Protocol: x402 v2
Auth: No account or API key. Pay per request.
Networks: Base, algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=, Solana
Demand: 3 calls · 3 unique payers in 30d (public x402 Bazaar data)

x402 payment requirements

Scheme	Network	Asset	Amount	Pay to	Timeout
exact	Base eip155:8453	USDC	$0.005	0x712c78928080Adb009E31315c0c3c7473dA9648a	120s
exact	algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8= algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=	31566704	5000	NLT4P2QFI3OO3PTLQHQXCAM2RA2Y7T4RZZKZF43BLMBKDFPFX54ZLDY2JU	120s
exact	Solana solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp	USDC	$0.005	9FDr6dYrxCRZYeaiXB86MqA9fuC3j5nH5u5fSQvD6QWd	120s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x712c78928080Adb009E31315c0c3c7473dA9648a",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "5000",
    "amountUsd": 0.005,
    "maxTimeoutSeconds": 120
  },
  {
    "scheme": "exact",
    "network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
    "payTo": "NLT4P2QFI3OO3PTLQHQXCAM2RA2Y7T4RZZKZF43BLMBKDFPFX54ZLDY2JU",
    "asset": "31566704",
    "amount": "5000",
    "maxTimeoutSeconds": 120
  },
  {
    "scheme": "exact",
    "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
    "payTo": "9FDr6dYrxCRZYeaiXB86MqA9fuC3j5nH5u5fSQvD6QWd",
    "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
    "amount": "5000",
    "amountUsd": 0.005,
    "maxTimeoutSeconds": 120
  }
]

Schemas

Output schema (JSON Schema)

{
  "properties": {
    "example": {
      "properties": {
        "latencyMs": {
          "properties": {
            "p50": {
              "type": "number"
            },
            "p99": {
              "type": "number"
            }
          },
          "type": "object"
        },
        "priceUsd": {
          "type": "number"
        },
        "problems": {
          "items": {
            "properties": {
              "detail": {
                "type": "string"
              },
              "id": {
                "type": "string"
              },
              "status": {
                "type": "string"
              }
            },
            "type": "object"
          },
          "type": "array"
        },
        "risk": {
          "type": "number"
        },
        "url": {
          "type": "string"
        },
        "verdict": {
          "type": "string"
        }
      },
      "type": "object"
    }
  },
  "type": "object"
}

Example shape — generated from the schema, not a captured live response

{
  "example": {
    "latencyMs": {
      "p50": 0,
      "p99": 0
    },
    "priceUsd": 0,
    "problems": [
      {
        "detail": "string",
        "id": "string",
        "status": "string"
      }
    ],
    "risk": 0,
    "url": "string",
    "verdict": "string"
  }
}

Examples

curl

curl "https://deadchannel.vercel.app/probe"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

JavaScript

const res = await fetch("https://deadchannel.vercel.app/probe");
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

Python

import httpx
res = httpx.get("https://deadchannel.vercel.app/probe")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header

Details

Provider: deadchannel.vercel.app
Endpoint: https://deadchannel.vercel.app/probe
Machine-readable: /resources/38709.json