api.402xagent.com

Live 402 challenge

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

{
  "asset": "USDC on Base (eip155:8453)",
  "error": "Payment required: $0.02 USDC on Base per lookup via x402. Free check first: https://api.402xagent.com/v1/products/endpoint-spot-check?url=<endpoint>",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x37cfCC8a29e9ff9458902B29E31E42dc7B718674",
      "amount": "20000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://api.402xagent.com/v1/lookup/paid",
    "tags": [
      "x402",
      "reliability",
      "receipts",
      "catalog",
      "agents"
    ],
    "mimeType": "application/json",
    "description": "Verified catalog reliability lookup: x402 endpoints for a task at or under a price, with our own paid receipts and known-answer pass/fail. $0.02 USDC on Base per call.",
    "serviceName": "Verified Catalog Lookup"
  },
  "price_usd": "0.02",
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "n": "5",
            "task": "web-search",
            "max_price": "0.01"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "query": {
              "n": 5,
              "task": "web-search",
              "limit": 10,
              "endpoint": null,
              "max_price_usd": 0.01
            },
            "access": {
              "tx": "0x...",
              "tier": "paid",
              "charged_usd": "0.02"
            },
            "matched": 1,
            "results": [
              {
                "id": "example-search",
                "stale": false,
                "endpoint": "https://example.com/search",
                "receipts": [
                  {
                    "tx": "0x...",
                    "time": "2026-10-02T18:48:42Z",
                    "quality": "pass",
                    "delivered": true,
                    "charged_usd": "0.01"
                  }
                ],
                "pass_rate": 1,
                "price_usd": "0.01"
              }
            ],
            "facts_only": [],
            "payment_policy": "Payment buys query access only. It never changes results, sort order, listings, check results or known-answer outcomes: free, paid and exempt lookups run the same code on the same data and get identical results."
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method"
            ],
            "properties": {
              "type": {
                "type": "string",
                "const": "http"
              },
              "method": {
                "enum": [
                  "GET"
                ],
                "type": "string"
              },
              "headers": {
                "type": "object",
                "additionalProperties": {
                  "type": "string"
                }
              },
              "queryParams": {
                "type": "object",
                "properties": {
                  "n": {
                    "type": "string",
                    "description": "paid receipts per service, 1-20 (default 5)"
                  },
                  "ref": {
                    "type": "string",
                    "description": "where you found this lookup (optional, attribution only)"
                  },
                  "task": {
                    "type": "string",
                    "description": "task name, e.g. web-search (see /v1/tasks); task or endpoint is required"
                  },
                  "limit": {
                    "type": "string",
                    "description": "services returned, 1-20 (default 10)"
                  },
                  "payer": {
                    "type": "string",
                    "description": "your 0x wallet (optional)"
                  },
                  "client": {
                    "type": "string",
                    "description": "your agent or app name (optional)"
                  },
                  "endpoint": {
                    "type": "string",
                    "description": "a service id or endpoint URL instead of a task"
                  },
                  "max_price": {
                    "type": "string",
                    "description": "maximum listed price per call, USD, e.g. 0.01"
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object"
              }
            }
          }
        }
      }
    }
  },
  "free_check": {
    "url": "https://api.402xagent.com/v1/products/endpoint-spot-check?url=<endpoint>",
    "free": "1 check per client per UTC day, plus free dry runs (&mode=dry-run). No payment, no key.",
    "then": "the paid check (HTTP 402, $0.01 to $0.25 USDC on Base) only for the full payment terms",
    "example": "https://api.402xagent.com/v1/products/endpoint-spot-check?url=https://api.402rates.com/v1/ping",
    "prior_checks": "https://402xagent.com/v1/skips",
    "example_response": {
      "reason": "listed $0.001, payment request matches, details locked",
      "verdict": "pay",
      "receipt_url": "https://402xagent.com/v1/receipts/sc-1373dc485641b938"
    }
  },
  "how_to_pay": "Retry the same request with a PAYMENT-SIGNATURE header (x402 v2; X-PAYMENT is also accepted) holding a signed USDC EIP-3009 authorization for the amount and payTo above. Bad parameters get a 400 before anything is settled.",
  "skips_page": {
    "url": "https://402xagent.com/v1/skips",
    "json": "https://402xagent.com/v1/skips.json",
    "description": "Free: 500 self-checked x402 endpoints, with the ones to skip before paying (claimed vs 402 price, pay-to, network)."
  },
  "x402Version": 2,
  "also_available": {
    "url": "https://402xagent.com/v1/products/overnight-cos-pack",
    "note": "Always-paid x402 product: prompts + HTML template + PDF guide after $9 USDC on Base.",
    "title": "Overnight Chief of Staff Setup Pack",
    "product": "overnight-cos-pack",
    "price_usdc": 9
  },
  "payment_policy": "Payment buys query access only. It never changes results, sort order, listings, check results or known-answer outcomes: free, paid and exempt lookups run the same code on the same data and get identical results.",
  "try_free_lookup": {
    "mcp": "https://402xagent.com/mcp",
    "ref": "via-402-hint",
    "url": "https://402xagent.com/v1/lookup?task=web-search&max_price=0.05&n=3&client=YOUR_CLIENT_ID&ref=via-402-hint",
    "description": "Same results as paid. 5 free calls per client per UTC day. Copy this URL (set your own client id)."
  },
  "free_alternative": "The same lookup is free for 5 calls per client per UTC day at /v1/lookup and via the free MCP server at /mcp. Payment never changes results.",
  "also_available_spot_check": {
    "url": "https://402xagent.com/v1/products/endpoint-spot-check?url=https%3A%2F%2Fexample.com&client=YOUR_CLIENT_ID&ref=via-402-hint",
    "note": "1 free SSRF-safe x402 challenge probe per client per UTC day, then $0.01 to $0.25 USDC (one tenth of the target's quoted price) on Base. Free result: verdict + plain reason; paid adds quoted/claimed price, pay-to, network.",
    "title": "402xAgent",
    "product": "endpoint-spot-check",
    "price_usdc": "0.01-0.25",
    "free_per_day": 1
  }
}

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": "0x37cfCC8a29e9ff9458902B29E31E42dc7B718674",
    "scheme": "exact",
    "network": "eip155:8453",
    "mimeType": "application/json",
    "resource": "https://api.402xagent.com/v1/lookup/paid",
    "description": "",
    "maxAmountRequired": "20000",
    "maxTimeoutSeconds": 300
  }
]

Provenance

Seen in the source catalog

2026-10-12 15:57Z

Last indexed by Roundhouse

2026-10-26 19:46Z

Last enriched (probe, favicon, geo)

2026-10-13 10:46Z

x402 version

1

Max timeout

300s

Liveness probe

HTTP 402