x402 List Submit a serviceSubmit

x402 Doctor

payment-readyonline

payment-ready until 2026-10-21

Checks x402 endpoints before an AI agent pays them: a $0.001 pre-payment check (go / caution / no_go, payout address screened against OFAC), a $0.01 full diagnosis with a fix hint per check, the fix as code, and a $0.25 paid delivery check that buys the endpoint once.

Call it x402 v2

x402 v2

Base URL
https://x402-doctor.fizzl.eu/
Payment
x402 v2, header channel
$ curl -i 'https://x402-doctor.fizzl.eu/api/v1/delivery-check'

An unpaid request returns HTTP 402 with the payment terms. Sign a payment authorization, then retry with the PAYMENT-SIGNATURE header.

Endpoints 6 paid routes on x402-doctor.fizzl.eu

GET/api/v1/delivery-checkBase+Sol$0.25since 10-14
GET/api/v1/diagnoseBase+Sol$0.01since 10-14
GET/api/v1/fixBase+Sol$0.05since 10-14
GET/api/v1/preflightBase+Sol$0.001since 10-14
GET/api/v1/preflight/batchBase+Sol$0.005since 10-14
GET/api/v1/preflight/deepBase+Sol$0.01since 10-14

Prices as captured in the 402 response: median $0.01 across the 6 endpoints, unchanged since first capture.

Example 402 response

Endpoints and prices

Current paid endpoints; minimum quoted prices in USD where available; first capture dates in UTC
MethodPathDescriptionPriceNetworkAsset402 channelCaptured
GET/api/v1/delivery-checkDoes this x402 endpoint really deliver? x402 Doctor buys it once with the example input its own listing declares (at most $0.1, USDC on Base), checks the answer against the declared output schema and measures the charge on chain. Answers with a job id at once; the result is public, usually within 30 minutes. For sellers who want proof, and buyers before a big order.$0.25Base+SolUSDC, UNKNOWNheadersince 10-14
GET/api/v1/diagnoseWhy is my x402 endpoint broken? Diagnose and debug an x402 payment endpoint (or MCP server) when payments fail: checks the 402 challenge, accepts[] (network, payTo, amount, asset), resource URL, Solana settlement readiness, which wallets and agents can pay, Bazaar/OpenAPI discovery and the browser paywall. Returns every check with a fix hint. Read-only: never pays. Bulk: 1000 credits for $0.80 via /api/v1/credits.$0.01Base+SolUSDC, UNKNOWNheadersince 10-14
GET/api/v1/fixHow do I fix my broken x402 endpoint? Diagnoses it, then returns per problem the concrete change as code for your stack (Express, Next.js, Hono or raw HTTP), filled in with your own payTo, amount, network and route. Bulk: 1000 credits for $0.80 via /api/v1/credits.$0.05Base+SolUSDC, UNKNOWNheadersince 10-14
GET/api/v1/preflightIs this x402 endpoint safe to pay? Call it before your AI agent pays an endpoint it has not used before. Returns a go / caution / no_go verdict, the recommended payment option (network and amount) and the reasons (payment would fail, payout address on the OFAC sanctions list, over your budget, price above advertised, not HTTPS, unknown token). Never pays the endpoint. Cached 10 min. Bulk: 1000 credits for $0.80 via /api/v1/credits.$0.001Base+SolUSDC, UNKNOWNheadersince 10-14
GET/api/v1/preflight/batchAre these x402 endpoints safe to pay? Up to 10 endpoints in one call (?url=a&url=b): per endpoint go / caution / no_go, the recommended payment option and why, plus totals. For marketplaces and agents that weigh several services. Never pays the endpoints. Bulk: 1000 credits for $0.80 via /api/v1/credits.$0.005Base+SolUSDC, UNKNOWNheadersince 10-14
GET/api/v1/preflight/deepShould my agent pay this expensive x402 endpoint? Call it before a costly or repeated payment. Returns the go / caution / no_go verdict plus the full diagnosis, the endpoint's check history per day over 30 days, how reliable the seller's other endpoints are and whether the endpoint moved domains. Never pays the endpoint. Bulk: 1000 credits for $0.80 via /api/v1/credits.$0.01Base+SolUSDC, UNKNOWNheadersince 10-14

Payment evidence

402 payload captured at . Check evidence JSON · Measurement methodology.

First of 6 payloads captured by the monitor.

375 lines, scroll inside

{
  "error": "Payment required",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x6B0F4651eD42893ab58139938175E4a69f175F25",
      "amount": "1000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
      "extra": {
        "feePayer": "CjNFTjvBhbJJd2B5ePPMHRLx1ELZpa8dwQgGL727eKww"
      },
      "payTo": "ATWJ82T8nRdQwZnaysB68N5EpaSvLRsQP4h6eWmaJBH9",
      "amount": "1000",
      "scheme": "exact",
      "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "524C555344000000000000000000000000000000",
      "extra": {
        "issuer": "rMxCKbEDwqr76QuheSUMdEGf4B9xJ8m5De",
        "invoiceId": "x402-doctor.fizzl.eu",
        "sourceTag": 804681468,
        "areFeesSponsored": false
      },
      "payTo": "r9xmBsRr8Ao7jRgjjxreMiAwGiCK2FGwqw",
      "amount": "0.001",
      "scheme": "exact",
      "network": "xrpl:0",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "31566704",
      "extra": {
        "feePayer": "ZMFK2OI7ZBD2U27ISERZC4S6LKM6WMFJPZQ4MYNJDZ2VNBNMBA67RA22AA"
      },
      "payTo": "LOYVFSQ6ZTS2YWUW4GQ5L6VPP2TPIOXWYDACK53CPOHQQHLDMEMKJDXAX4",
      "amount": "1000",
      "scheme": "exact",
      "network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://x402-doctor.fizzl.eu/api/v1/preflight",
    "tags": [
      "x402",
      "payments",
      "safety",
      "pre-payment",
      "sanctions"
    ],
    "iconUrl": "https://x402-doctor.fizzl.eu/icon.png",
    "mimeType": "application/json",
    "description": "Is this x402 endpoint safe to pay? Call it before your AI agent pays an endpoint it has not used before. Returns a go / caution / no_go verdict, the recommended payment option (network and amount) and the reasons (payment would fail, payout address on the OFAC sanctions list, over your budget, price above advertised, not HTTPS, unknown token). Never pays the endpoint. Cached 10 min. Bulk: 1000 credits for $0.80 via /api/v1/credits.",
    "serviceName": "x402 Doctor"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "url": "https://ichimoku-signal.fizzl.eu/signal/BTC-USDT",
            "max_usd": "0.05"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "url": "https://ichimoku-signal.fizzl.eu/signal/BTC-USDT",
            "cached": false,
            "method": "GET",
            "options": [
              {
                "usd": 0.02,
                "index": 0,
                "amount": "20000",
                "pay_to": "0x6B0F4651eD42893ab58139938175E4a69f175F25",
                "network": "eip155:8453",
                "payable": true,
                "problems": [],
                "asset_symbol": "USDC",
                "network_name": "Base"
              }
            ],
            "reasons": [],
            "signals": {
              "https": true,
              "advertised_price_usd": 0.02,
              "listed_in_cdp_bazaar": false
            },
            "summary": "OK to pay: $0.02 on Base.",
            "verdict": "go",
            "checked_at": "2026-09-23T17:00:00.000Z",
            "safe_to_pay": true,
            "recommended_option": 0
          }
        }
      },
      "schema": {
        "type": "object",
        "$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"
              },
              "queryParams": {
                "type": "object",
                "required": [
                  "url"
                ],
                "properties": {
                  "url": {
                    "type": "string",
                    "description": "The x402 endpoint you are about to pay."
                  },
                  "method": {
                    "enum": [
                      "GET",
                      "POST"
                    ],
                    "type": "string",
                    "description": "HTTP method you will call it with. Default: try GET, then POST."
                  },
                  "max_usd": {
                    "type": "string",
                    "description": "Your budget per call in USD; above it the verdict is no_go."
                  },
                  "network": {
                    "type": "string",
                    "description": "CAIP-2 network you want to pay on, e.g. eip155:8453 or solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp."
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object",
                "required": [
                  "url",
                  "verdict",
                  "safe_to_pay",
                  "summary",
                  "options",
                  "reasons"
                ],
                "properties": {
                  "url": {
                    "type": "string"
                  },
                  "cached": {
                    "type": "boolean"
                  },
                  "method": {
                    "type": [
                      "string",
                      "null"
                    ]
                  },
                  "options": {
                    "type": "array",
                    "items": {
                      "type": "object",
                      "required": [
                        "index",
                        "payable",
                        "problems"
                      ],
                      "properties": {
                        "usd": {
                          "type": [
                            "number",
                            "null"
                          ]
                        },
                        "index": {
                          "type": "integer"
                        },
                        "amount": {
                          "type": [
                            "string",
                            "null"
                          ]
                        },
                        "method": {
                          "type": [
                            "string",
                            "null"
                          ],
                          "description": "MPP payment method (evm, tempo, stripe); absent for x402 options"
                        },
                        "pay_to": {
                          "type": [
                            "string",
                            "null"
                          ]
                        },
                        "network": {
                          "type": [
                            "string",
                            "null"
                          ]
                        },
                        "payable": {
                          "type": "boolean"
                        },
                        "problems": {
                          "type": "array",
                          "items": {
                            "type": "string"
                          }
                        },
                        "protocol": {
                          "enum": [
                            "x402",
                            "mpp",
                            "l402"
                          ],
                          "type": "string"
                        },
                        "asset_symbol": {
                          "type": [
                            "string",
                            "null"
                          ]
                        },
                        "network_name": {
                          "type": [
                            "string",
                            "null"
                          ]
                        }
                      }
                    }
                  },
                  "reasons": {
                    "type": "array",
                    "items": {
                      "type": "object",
                      "required": [
                        "level",
                        "code",
                        "message"
                      ],
                      "properties": {
                        "code": {
                          "type": "string"
                        },
                        "level": {
                          "enum": [
                            "no_go",
                            "caution",
                            "info"
                          ],
                          "type": "string"
                        },
                        "message": {
                          "type": "string"
                        }
                      }
                    }
                  },
                  "signals": {
                    "type": "object"
                  },
                  "summary": {
                    "type": "string"
                  },
                  "verdict": {
                    "enum": [
                      "go",
                      "caution",
                      "no_go"
                    ],
                    "type": "string"
                  },
                  "checked_at": {
                    "type": "string"
                  },
                  "safe_to_pay": {
                    "type": "boolean"
                  },
                  "recommended_option": {
                    "type": [
                      "integer",
                      "null"
                    ]
                  }
                }
              }
            }
          }
        }
      }
    },
    "x402-merchant": {
      "info": {
        "logo": "https://fizzl.eu/logo-512.png",
        "name": "Fizzl",
        "website": "https://fizzl.eu",
        "categories": [
          "ai-agents",
          "security",
          "trading-signals",
          "developer-tools",
          "x402",
          "algorand"
        ]
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "name"
        ],
        "properties": {
          "logo": {
            "type": "string"
          },
          "name": {
            "type": "string"
          },
          "website": {
            "type": "string"
          },
          "categories": {
            "type": "array",
            "items": {
              "type": "string"
            }
          }
        }
      }
    }
  },
  "x402Version": 2
}
Other captured 402 responses (5)

Captured payload 2 of 6

{
  "error": "Payment required",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x6B0F4651eD42893ab58139938175E4a69f175F25",
      "amount": "5000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
      "extra": {
        "feePayer": "CjNFTjvBhbJJd2B5ePPMHRLx1ELZpa8dwQgGL727eKww"
      },
      "payTo": "ATWJ82T8nRdQwZnaysB68N5EpaSvLRsQP4h6eWmaJBH9",
      "amount": "5000",
      "scheme": "exact",
      "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "524C555344000000000000000000000000000000",
      "extra": {
        "issuer": "rMxCKbEDwqr76QuheSUMdEGf4B9xJ8m5De",
        "invoiceId": "x402-doctor.fizzl.eu",
        "sourceTag": 804681468,
        "areFeesSponsored": false
      },
      "payTo": "r9xmBsRr8Ao7jRgjjxreMiAwGiCK2FGwqw",
      "amount": "0.005",
      "scheme": "exact",
      "network": "xrpl:0",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "31566704",
      "extra": {
        "feePayer": "ZMFK2OI7ZBD2U27ISERZC4S6LKM6WMFJPZQ4MYNJDZ2VNBNMBA67RA22AA"
      },
      "payTo": "LOYVFSQ6ZTS2YWUW4GQ5L6VPP2TPIOXWYDACK53CPOHQQHLDMEMKJDXAX4",
      "amount": "5000",
      "scheme": "exact",
      "network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://x402-doctor.fizzl.eu/api/v1/preflight/batch",
    "tags": [
      "x402",
      "payments",
      "safety",
      "pre-payment",
      "batch"
    ],
    "iconUrl": "https://x402-doctor.fizzl.eu/icon.png",
    "mimeType": "application/json",
    "description": "Are these x402 endpoints safe to pay? Up to 10 endpoints in one call (?url=a&url=b): per endpoint go / caution / no_go, the recommended payment option and why, plus totals. For marketplaces and agents that weigh several services. Never pays the endpoints. Bulk: 1000 credits for $0.80 via /api/v1/credits.",
    "serviceName": "x402 Doctor"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "url": [
              "https://ichimoku-signal.fizzl.eu/signal/BTC-USDT",
              "https://presign-guard.fizzl.eu/v1/token"
            ],
            "max_usd": "0.05"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "count": 2,
            "counts": {
              "go": 2,
              "no_go": 0,
              "caution": 0,
              "unknown": 0
            },
            "results": [
              {
                "url": "https://ichimoku-signal.fizzl.eu/signal/BTC-USDT",
                "options": [],
                "reasons": [],
                "summary": "OK to pay: $0.02 on Base.",
                "verdict": "go",
                "safe_to_pay": true,
                "recommended_option": 0
              },
              {
                "url": "https://presign-guard.fizzl.eu/v1/token",
                "options": [],
                "reasons": [],
                "summary": "OK to pay: $0.01 on Base.",
                "verdict": "go",
                "safe_to_pay": true,
                "recommended_option": 0
              }
            ],
            "checked_at": "2026-09-29T12:00:00.000Z"
          }
        }
      },
      "schema": {
        "type": "object",
        "$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"
              },
              "queryParams": {
                "type": "object",
                "required": [
                  "url"
                ],
                "properties": {
                  "url": {
                    "type": "array",
                    "items": {
                      "type": "string"
                    },
                    "maxItems": 10,
                    "description": "The x402 endpoints to check, one url parameter each (?url=a&url=b), at most 10."
                  },
                  "method": {
                    "enum": [
                      "GET",
                      "POST"
                    ],
                    "type": "string",
                    "description": "HTTP method you will call them with. Default: try GET, then POST."
                  },
                  "max_usd": {
                    "type": "string",
                    "description": "Your budget per call in USD; above it the verdict is no_go."
                  },
                  "network": {
                    "type": "string",
                    "description": "CAIP-2 network you want to pay on."
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object",
                "required": [
                  "count",
                  "counts",
                  "results"
                ],
                "properties": {
                  "count": {
                    "type": "integer"
                  },
                  "counts": {
                    "type": "object",
                    "properties": {
                      "go": {
                        "type": "integer"
                      },
                      "no_go": {
                        "type": "integer"
                      },
                      "caution": {
                        "type": "integer"
                      },
                      "unknown": {
                        "type": "integer"
                      }
                    }
                  },
                  "results": {
                    "type": "array",
                    "items": {
                      "type": "object",
                      "required": [
                        "url",
                        "verdict",
                        "safe_to_pay",
                        "summary"
                      ],
                      "properties": {
                        "url": {
                          "type": "string"
                        },
                        "error": {
                          "type": "string"
                        },
                        "options": {
                          "type": "array"
                        },
                        "reasons": {
                          "type": "array"
                        },
                        "summary": {
                          "type": "string"
                        },
                        "verdict": {
                          "enum": [
                            "go",
                            "caution",
                            "no_go",
                            "unknown"
                          ],
                          "type": "string"
                        },
                        "safe_to_pay": {
                          "type": "boolean"
                        },
                        "recommended_option": {
                          "type": [
                            "integer",
                            "null"
                          ]
                        }
                      }
                    }
                  },
                  "checked_at": {
                    "type": "string"
                  }
                }
              }
            }
          }
        }
      }
    },
    "x402-merchant": {
      "info": {
        "logo": "https://fizzl.eu/logo-512.png",
        "name": "Fizzl",
        "website": "https://fizzl.eu",
        "categories": [
          "ai-agents",
          "security",
          "trading-signals",
          "developer-tools",
          "x402",
          "algorand"
        ]
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "name"
        ],
        "properties": {
          "logo": {
            "type": "string"
          },
          "name": {
            "type": "string"
          },
          "website": {
            "type": "string"
          },
          "categories": {
            "type": "array",
            "items": {
              "type": "string"
            }
          }
        }
      }
    }
  },
  "x402Version": 2
}

Captured payload 3 of 6

{
  "error": "Payment required",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x6B0F4651eD42893ab58139938175E4a69f175F25",
      "amount": "10000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
      "extra": {
        "feePayer": "CjNFTjvBhbJJd2B5ePPMHRLx1ELZpa8dwQgGL727eKww"
      },
      "payTo": "ATWJ82T8nRdQwZnaysB68N5EpaSvLRsQP4h6eWmaJBH9",
      "amount": "10000",
      "scheme": "exact",
      "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "524C555344000000000000000000000000000000",
      "extra": {
        "issuer": "rMxCKbEDwqr76QuheSUMdEGf4B9xJ8m5De",
        "invoiceId": "x402-doctor.fizzl.eu",
        "sourceTag": 804681468,
        "areFeesSponsored": false
      },
      "payTo": "r9xmBsRr8Ao7jRgjjxreMiAwGiCK2FGwqw",
      "amount": "0.01",
      "scheme": "exact",
      "network": "xrpl:0",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "31566704",
      "extra": {
        "feePayer": "ZMFK2OI7ZBD2U27ISERZC4S6LKM6WMFJPZQ4MYNJDZ2VNBNMBA67RA22AA"
      },
      "payTo": "LOYVFSQ6ZTS2YWUW4GQ5L6VPP2TPIOXWYDACK53CPOHQQHLDMEMKJDXAX4",
      "amount": "10000",
      "scheme": "exact",
      "network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://x402-doctor.fizzl.eu/api/v1/preflight/deep",
    "tags": [
      "x402",
      "payments",
      "safety",
      "pre-payment",
      "due-diligence"
    ],
    "iconUrl": "https://x402-doctor.fizzl.eu/icon.png",
    "mimeType": "application/json",
    "description": "Should my agent pay this expensive x402 endpoint? Call it before a costly or repeated payment. Returns the go / caution / no_go verdict plus the full diagnosis, the endpoint's check history per day over 30 days, how reliable the seller's other endpoints are and whether the endpoint moved domains. Never pays the endpoint. Bulk: 1000 credits for $0.80 via /api/v1/credits.",
    "serviceName": "x402 Doctor"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "url": "https://ichimoku-signal.fizzl.eu/setups",
            "max_usd": "0.5"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "url": "https://ichimoku-signal.fizzl.eu/setups",
            "domain": {
              "checks": []
            },
            "seller": {
              "origin": "https://ichimoku-signal.fizzl.eu",
              "resources": 6,
              "unreliable": 0,
              "payable_now": 6,
              "avg_payable_ratio": 1
            },
            "history": [
              {
                "date": "2026-09-28",
                "status": "go"
              }
            ],
            "options": [],
            "reasons": [],
            "summary": "OK to pay: $0.5 on Base.",
            "verdict": "go",
            "diagnosis": {
              "checks": [],
              "overall": "pass",
              "problems": []
            },
            "safe_to_pay": true,
            "recommended_option": 0
          }
        }
      },
      "schema": {
        "type": "object",
        "$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"
              },
              "queryParams": {
                "type": "object",
                "required": [
                  "url"
                ],
                "properties": {
                  "url": {
                    "type": "string",
                    "description": "The x402 endpoint you are about to pay (worth it for expensive calls)."
                  },
                  "method": {
                    "enum": [
                      "GET",
                      "POST"
                    ],
                    "type": "string",
                    "description": "HTTP method you will call it with. Default: try GET, then POST."
                  },
                  "max_usd": {
                    "type": "string",
                    "description": "Your budget per call in USD; above it the verdict is no_go."
                  },
                  "network": {
                    "type": "string",
                    "description": "CAIP-2 network you want to pay on."
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object",
                "required": [
                  "url",
                  "verdict",
                  "safe_to_pay",
                  "summary",
                  "options",
                  "reasons"
                ],
                "properties": {
                  "url": {
                    "type": "string"
                  },
                  "cached": {
                    "type": "boolean"
                  },
                  "domain": {
                    "type": "object",
                    "properties": {
                      "checks": {
                        "type": "array"
                      }
                    }
                  },
                  "method": {
                    "type": [
                      "string",
                      "null"
                    ]
                  },
                  "seller": {
                    "type": [
                      "object",
                      "null"
                    ],
                    "properties": {
                      "origin": {
                        "type": "string"
                      },
                      "resources": {
                        "type": "integer"
                      },
                      "unreliable": {
                        "type": "integer"
                      },
                      "payable_now": {
                        "type": "integer"
                      },
                      "avg_payable_ratio": {
                        "type": "number"
                      }
                    }
                  },
                  "history": {
                    "type": "array",
                    "items": {
                      "type": "object",
                      "properties": {
                        "date": {
                          "type": [
                            "string",
                            "null"
                          ]
                        },
                        "status": {
                          "enum": [
                            "go",
                            "caution",
                            "no_go",
                            "unreachable",
                            "unknown"
                          ],
                          "type": "string"
                        }
                      }
                    }
                  },
                  "options": {
                    "type": "array",
                    "items": {
                      "type": "object",
                      "required": [
                        "index",
                        "payable",
                        "problems"
                      ],
                      "properties": {
                        "usd": {
                          "type": [
                            "number",
                            "null"
                          ]
                        },
                        "index": {
                          "type": "integer"
                        },
                        "amount": {
                          "type": [
                            "string",
                            "null"
                          ]
                        },
                        "method": {
                          "type": [
                            "string",
                            "null"
                          ],
                          "description": "MPP payment method (evm, tempo, stripe); absent for x402 options"
                        },
                        "pay_to": {
                          "type": [
                            "string",
                            "null"
                          ]
                        },
                        "network": {
                          "type": [
                            "string",
                            "null"
                          ]
                        },
                        "payable": {
                          "type": "boolean"
                        },
                        "problems": {
                          "type": "array",
                          "items": {
                            "type": "string"
                          }
                        },
                        "protocol": {
                          "enum": [
                            "x402",
                            "mpp",
                            "l402"
                          ],
                          "type": "string"
                        },
                        "asset_symbol": {
                          "type": [
                            "string",
                            "null"
                          ]
                        },
                        "network_name": {
                          "type": [
                            "string",
                            "null"
                          ]
                        }
                      }
                    }
                  },
                  "reasons": {
                    "type": "array",
                    "items": {
                      "type": "object",
                      "required": [
                        "level",
                        "code",
                        "message"
                      ],
                      "properties": {
                        "code": {
                          "type": "string"
                        },
                        "level": {
                          "enum": [
                            "no_go",
                            "caution",
                            "info"
                          ],
                          "type": "string"
                        },
                        "message": {
                          "type": "string"
                        }
                      }
                    }
                  },
                  "signals": {
                    "type": "object"
                  },
                  "summary": {
                    "type": "string"
                  },
                  "verdict": {
                    "enum": [
                      "go",
                      "caution",
                      "no_go"
                    ],
                    "type": "string"
                  },
                  "diagnosis": {
                    "type": "object",
                    "properties": {
                      "checks": {
                        "type": "array"
                      },
                      "overall": {
                        "type": [
                          "string",
                          "null"
                        ]
                      },
                      "problems": {
                        "type": "array"
                      }
                    }
                  },
                  "checked_at": {
                    "type": "string"
                  },
                  "safe_to_pay": {
                    "type": "boolean"
                  },
                  "recommended_option": {
                    "type": [
                      "integer",
                      "null"
                    ]
                  }
                }
              }
            }
          }
        }
      }
    },
    "x402-merchant": {
      "info": {
        "logo": "https://fizzl.eu/logo-512.png",
        "name": "Fizzl",
        "website": "https://fizzl.eu",
        "categories": [
          "ai-agents",
          "security",
          "trading-signals",
          "developer-tools",
          "x402",
          "algorand"
        ]
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "name"
        ],
        "properties": {
          "logo": {
            "type": "string"
          },
          "name": {
            "type": "string"
          },
          "website": {
            "type": "string"
          },
          "categories": {
            "type": "array",
            "items": {
              "type": "string"
            }
          }
        }
      }
    }
  },
  "x402Version": 2
}

Captured payload 4 of 6

{
  "error": "Payment required",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x6B0F4651eD42893ab58139938175E4a69f175F25",
      "amount": "10000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
      "extra": {
        "feePayer": "CjNFTjvBhbJJd2B5ePPMHRLx1ELZpa8dwQgGL727eKww"
      },
      "payTo": "ATWJ82T8nRdQwZnaysB68N5EpaSvLRsQP4h6eWmaJBH9",
      "amount": "10000",
      "scheme": "exact",
      "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "524C555344000000000000000000000000000000",
      "extra": {
        "issuer": "rMxCKbEDwqr76QuheSUMdEGf4B9xJ8m5De",
        "invoiceId": "x402-doctor.fizzl.eu",
        "sourceTag": 804681468,
        "areFeesSponsored": false
      },
      "payTo": "r9xmBsRr8Ao7jRgjjxreMiAwGiCK2FGwqw",
      "amount": "0.01",
      "scheme": "exact",
      "network": "xrpl:0",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "31566704",
      "extra": {
        "feePayer": "ZMFK2OI7ZBD2U27ISERZC4S6LKM6WMFJPZQ4MYNJDZ2VNBNMBA67RA22AA"
      },
      "payTo": "LOYVFSQ6ZTS2YWUW4GQ5L6VPP2TPIOXWYDACK53CPOHQQHLDMEMKJDXAX4",
      "amount": "10000",
      "scheme": "exact",
      "network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://x402-doctor.fizzl.eu/api/v1/diagnose",
    "tags": [
      "x402",
      "developer-tools",
      "diagnostics",
      "debug",
      "payments"
    ],
    "iconUrl": "https://x402-doctor.fizzl.eu/icon.png",
    "mimeType": "application/json",
    "description": "Why is my x402 endpoint broken? Diagnose and debug an x402 payment endpoint (or MCP server) when payments fail: checks the 402 challenge, accepts[] (network, payTo, amount, asset), resource URL, Solana settlement readiness, which wallets and agents can pay, Bazaar/OpenAPI discovery and the browser paywall. Returns every check with a fix hint. Read-only: never pays. Bulk: 1000 credits for $0.80 via /api/v1/credits.",
    "serviceName": "x402 Doctor"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "url": "https://ichimoku-signal.fizzl.eu/signal/BTC-USDT",
            "method": "GET"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "url": "https://ichimoku-signal.fizzl.eu/signal/BTC-USDT",
            "checks": [
              {
                "id": "returns-402",
                "group": "challenge",
                "status": "pass",
                "message": "Endpoint returns 402 Payment Required for GET."
              }
            ],
            "method": "GET",
            "overall": "pass",
            "challenge": null
          }
        }
      },
      "schema": {
        "type": "object",
        "$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"
              },
              "queryParams": {
                "type": "object",
                "required": [
                  "url"
                ],
                "properties": {
                  "url": {
                    "type": "string",
                    "description": "The x402 endpoint to diagnose (public http(s) URL)."
                  },
                  "method": {
                    "enum": [
                      "GET",
                      "POST"
                    ],
                    "type": "string",
                    "description": "HTTP method of the endpoint. Default: try GET, then POST."
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object",
                "required": [
                  "url",
                  "overall",
                  "checks"
                ],
                "properties": {
                  "url": {
                    "type": "string"
                  },
                  "checks": {
                    "type": "array",
                    "items": {
                      "type": "object",
                      "required": [
                        "id",
                        "status",
                        "message"
                      ],
                      "properties": {
                        "id": {
                          "type": "string"
                        },
                        "hint": {
                          "type": "string"
                        },
                        "group": {
                          "enum": [
                            "challenge",
                            "accepts",
                            "resource",
                            "settlement",
                            "wallets",
                            "discovery",
                            "browser"
                          ],
                          "type": "string"
                        },
                        "status": {
                          "enum": [
                            "pass",
                            "warn",
                            "fail",
                            "info",
                            "skip"
                          ],
                          "type": "string"
                        },
                        "message": {
                          "type": "string"
                        }
                      }
                    }
                  },
                  "method": {
                    "enum": [
                      "GET",
                      "POST",
                      null
                    ],
                    "type": [
                      "string",
                      "null"
                    ]
                  },
                  "overall": {
                    "enum": [
                      "pass",
                      "warn",
                      "fail"
                    ],
                    "type": "string"
                  },
                  "wallets": {
                    "type": "array",
                    "items": {
                      "type": "object",
                      "properties": {
                        "no": {
                          "type": "array",
                          "items": {
                            "type": "object",
                            "properties": {
                              "reason": {
                                "type": "string"
                              },
                              "network": {
                                "type": "string"
                              }
                            }
                          }
                        },
                        "yes": {
                          "type": "array",
                          "items": {
                            "type": "string"
                          }
                        },
                        "agent": {
                          "type": "boolean"
                        },
                        "wallet": {
                          "type": "string"
                        }
                      }
                    },
                    "description": "Which wallets can pay: per wallet, the networks where payment works (yes) and where it fails, with the reason (no)."
                  },
                  "challenge": {
                    "type": [
                      "object",
                      "null"
                    ]
                  }
                }
              }
            }
          }
        }
      }
    },
    "x402-merchant": {
      "info": {
        "logo": "https://fizzl.eu/logo-512.png",
        "name": "Fizzl",
        "website": "https://fizzl.eu",
        "categories": [
          "ai-agents",
          "security",
          "trading-signals",
          "developer-tools",
          "x402",
          "algorand"
        ]
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "name"
        ],
        "properties": {
          "logo": {
            "type": "string"
          },
          "name": {
            "type": "string"
          },
          "website": {
            "type": "string"
          },
          "categories": {
            "type": "array",
            "items": {
              "type": "string"
            }
          }
        }
      }
    }
  },
  "x402Version": 2
}

Captured payload 5 of 6

{
  "error": "Payment required",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x6B0F4651eD42893ab58139938175E4a69f175F25",
      "amount": "50000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
      "extra": {
        "feePayer": "CjNFTjvBhbJJd2B5ePPMHRLx1ELZpa8dwQgGL727eKww"
      },
      "payTo": "ATWJ82T8nRdQwZnaysB68N5EpaSvLRsQP4h6eWmaJBH9",
      "amount": "50000",
      "scheme": "exact",
      "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "524C555344000000000000000000000000000000",
      "extra": {
        "issuer": "rMxCKbEDwqr76QuheSUMdEGf4B9xJ8m5De",
        "invoiceId": "x402-doctor.fizzl.eu",
        "sourceTag": 804681468,
        "areFeesSponsored": false
      },
      "payTo": "r9xmBsRr8Ao7jRgjjxreMiAwGiCK2FGwqw",
      "amount": "0.05",
      "scheme": "exact",
      "network": "xrpl:0",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "31566704",
      "extra": {
        "feePayer": "ZMFK2OI7ZBD2U27ISERZC4S6LKM6WMFJPZQ4MYNJDZ2VNBNMBA67RA22AA"
      },
      "payTo": "LOYVFSQ6ZTS2YWUW4GQ5L6VPP2TPIOXWYDACK53CPOHQQHLDMEMKJDXAX4",
      "amount": "50000",
      "scheme": "exact",
      "network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://x402-doctor.fizzl.eu/api/v1/fix",
    "tags": [
      "x402",
      "developer-tools",
      "fix",
      "code"
    ],
    "iconUrl": "https://x402-doctor.fizzl.eu/icon.png",
    "mimeType": "application/json",
    "description": "How do I fix my broken x402 endpoint? Diagnoses it, then returns per problem the concrete change as code for your stack (Express, Next.js, Hono or raw HTTP), filled in with your own payTo, amount, network and route. Bulk: 1000 credits for $0.80 via /api/v1/credits.",
    "serviceName": "x402 Doctor"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "url": "https://x402-doctor.fizzl.eu/demo/broken"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "url": "https://x402-doctor.fizzl.eu/demo/broken",
            "fixes": [
              {
                "why": "x402 amounts are integer strings in the smallest unit.",
                "code": [
                  {
                    "label": "Option field",
                    "stack": "generic",
                    "snippet": "\"amount\": \"10000\"",
                    "language": "json"
                  }
                ],
                "steps": [
                  "Use price: \"$0.01\" instead of an amount."
                ],
                "title": "Amount \"0.01\" → \"10000\" ($0.01)",
                "checks": [
                  "accepts[0]-amount"
                ],
                "recipe": "amount",
                "verify": "Run x402 Doctor again.",
                "severity": "warn"
              }
            ],
            "stack": {
              "id": "express",
              "name": "Express (@x402/express)",
              "detected_from": "x-powered-by: Express"
            },
            "overall": "fail",
            "summary": "1 fix (0 blocking), for Express (@x402/express).",
            "unfixed": []
          }
        }
      },
      "schema": {
        "type": "object",
        "$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"
              },
              "queryParams": {
                "type": "object",
                "required": [
                  "url"
                ],
                "properties": {
                  "url": {
                    "type": "string",
                    "description": "Your x402 endpoint (public http(s) URL)."
                  },
                  "stack": {
                    "enum": [
                      "express",
                      "next",
                      "hono",
                      "node",
                      "python",
                      "generic"
                    ],
                    "type": "string",
                    "description": "Your stack, if detection from response headers is wrong. Default: detected."
                  },
                  "method": {
                    "enum": [
                      "GET",
                      "POST"
                    ],
                    "type": "string",
                    "description": "HTTP method of the endpoint. Default: try GET, then POST."
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object",
                "required": [
                  "url",
                  "fixes"
                ],
                "properties": {
                  "url": {
                    "type": "string"
                  },
                  "fixes": {
                    "type": "array",
                    "items": {
                      "type": "object",
                      "required": [
                        "title",
                        "why",
                        "steps",
                        "code"
                      ],
                      "properties": {
                        "why": {
                          "type": "string"
                        },
                        "code": {
                          "type": "array",
                          "items": {
                            "type": "object",
                            "properties": {
                              "label": {
                                "type": "string"
                              },
                              "stack": {
                                "type": "string"
                              },
                              "snippet": {
                                "type": "string"
                              },
                              "language": {
                                "type": "string"
                              }
                            }
                          }
                        },
                        "steps": {
                          "type": "array",
                          "items": {
                            "type": "string"
                          }
                        },
                        "title": {
                          "type": "string"
                        },
                        "checks": {
                          "type": "array",
                          "items": {
                            "type": "string"
                          }
                        },
                        "recipe": {
                          "type": "string"
                        },
                        "verify": {
                          "type": "string"
                        },
                        "severity": {
                          "enum": [
                            "fail",
                            "warn"
                          ],
                          "type": "string"
                        }
                      }
                    }
                  },
                  "stack": {
                    "type": "object",
                    "properties": {
                      "id": {
                        "enum": [
                          "express",
                          "next",
                          "hono",
                          "node",
                          "python",
                          "generic"
                        ],
                        "type": "string"
                      },
                      "name": {
                        "type": "string"
                      },
                      "detected_from": {
                        "type": "string"
                      }
                    }
                  },
                  "overall": {
                    "enum": [
                      "pass",
                      "warn",
                      "fail"
                    ],
                    "type": "string"
                  },
                  "summary": {
                    "type": "string"
                  },
                  "unfixed": {
                    "type": "array",
                    "items": {
                      "type": "object"
                    }
                  }
                }
              }
            }
          }
        }
      }
    },
    "x402-merchant": {
      "info": {
        "logo": "https://fizzl.eu/logo-512.png",
        "name": "Fizzl",
        "website": "https://fizzl.eu",
        "categories": [
          "ai-agents",
          "security",
          "trading-signals",
          "developer-tools",
          "x402",
          "algorand"
        ]
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "name"
        ],
        "properties": {
          "logo": {
            "type": "string"
          },
          "name": {
            "type": "string"
          },
          "website": {
            "type": "string"
          },
          "categories": {
            "type": "array",
            "items": {
              "type": "string"
            }
          }
        }
      }
    }
  },
  "x402Version": 2
}

Captured payload 6 of 6

{
  "error": "Payment required",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x6B0F4651eD42893ab58139938175E4a69f175F25",
      "amount": "250000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
      "extra": {
        "feePayer": "CjNFTjvBhbJJd2B5ePPMHRLx1ELZpa8dwQgGL727eKww"
      },
      "payTo": "ATWJ82T8nRdQwZnaysB68N5EpaSvLRsQP4h6eWmaJBH9",
      "amount": "250000",
      "scheme": "exact",
      "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "524C555344000000000000000000000000000000",
      "extra": {
        "issuer": "rMxCKbEDwqr76QuheSUMdEGf4B9xJ8m5De",
        "invoiceId": "x402-doctor.fizzl.eu",
        "sourceTag": 804681468,
        "areFeesSponsored": false
      },
      "payTo": "r9xmBsRr8Ao7jRgjjxreMiAwGiCK2FGwqw",
      "amount": "0.25",
      "scheme": "exact",
      "network": "xrpl:0",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "31566704",
      "extra": {
        "feePayer": "ZMFK2OI7ZBD2U27ISERZC4S6LKM6WMFJPZQ4MYNJDZ2VNBNMBA67RA22AA"
      },
      "payTo": "LOYVFSQ6ZTS2YWUW4GQ5L6VPP2TPIOXWYDACK53CPOHQQHLDMEMKJDXAX4",
      "amount": "250000",
      "scheme": "exact",
      "network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://x402-doctor.fizzl.eu/api/v1/delivery-check",
    "tags": [
      "x402",
      "payments",
      "verification",
      "delivery",
      "trust"
    ],
    "iconUrl": "https://x402-doctor.fizzl.eu/icon.png",
    "mimeType": "application/json",
    "description": "Does this x402 endpoint really deliver? x402 Doctor buys it once with the example input its own listing declares (at most $0.1, USDC on Base), checks the answer against the declared output schema and measures the charge on chain. Answers with a job id at once; the result is public, usually within 30 minutes. For sellers who want proof, and buyers before a big order.",
    "serviceName": "x402 Doctor"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "url": "https://rest.coincap.io/v3/agentFriendly/full_assets_by_slug"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "id": "k3v9x2m7qa",
            "eta": "usually within 30 minutes",
            "url": "https://rest.coincap.io/v3/agentFriendly/full_assets_by_slug",
            "method": null,
            "status": "queued",
            "queued_at": "2026-10-12T17:00:00.000Z",
            "status_url": "https://x402-doctor.fizzl.eu/api/v1/delivery-check/k3v9x2m7qa",
            "endpoint_price_usd": 0.002
          }
        }
      },
      "schema": {
        "type": "object",
        "$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"
              },
              "queryParams": {
                "type": "object",
                "required": [
                  "url"
                ],
                "properties": {
                  "url": {
                    "type": "string",
                    "description": "The x402 endpoint to buy once (https, payable in USDC on Base, at most $0.1)."
                  },
                  "method": {
                    "enum": [
                      "GET",
                      "POST"
                    ],
                    "type": "string",
                    "description": "HTTP method of the endpoint. Default: the one its 402 answers to."
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object"
              }
            }
          }
        }
      }
    },
    "x402-merchant": {
      "info": {
        "logo": "https://fizzl.eu/logo-512.png",
        "name": "Fizzl",
        "website": "https://fizzl.eu",
        "categories": [
          "ai-agents",
          "security",
          "trading-signals",
          "developer-tools",
          "x402",
          "algorand"
        ]
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "name"
        ],
        "properties": {
          "logo": {
            "type": "string"
          },
          "name": {
            "type": "string"
          },
          "website": {
            "type": "string"
          },
          "categories": {
            "type": "array",
            "items": {
              "type": "string"
            }
          }
        }
      }
    }
  },
  "x402Version": 2
}

Can I trust it score from our own monitoring

score from our own monitoring

88/100 Solid

#10 of 138 in Verification. Bands: strong 93+, solid 75+, mixed 55+, weak below 55.

Reliability
100% uptime since 10-14
Compliance
A 14/14 checks pass
Price
$0.001 to $0.25 p7 in Verification
Risk
clean no risk flag
Traction
$0.00 30d 0 buyers
14/14 compliance checks
  • 402 payload captured
  • accepts[] array present
  • payTo address recoverable
  • payTo at accepts[0].payTo (conformant shape)
  • payTo is a valid on-chain address
  • atomic price declared
  • atomic price in a sane range
  • asset (token) address declared
  • network resolves to CAIP-2
  • payment scheme declared
  • served over HTTPS
  • declares the current x402 version (2)
  • EIP-712 domain parameters present on every EVM entry
  • x402 v2 envelope delivered in the payment-required header

402 terms unchanged since 2026-10-14. Last up 2026-10-14.

── Site signals

  • homepage reachable
  • openapi doc
  • pricing page
  • llms.txt
  • robots.txt
  • terms page
How the score works

What the score read on this service: status online, 100% uptime, latest daily rollup (no 30d window yet), 534ms response p95, x402 compliance 14 of 14, $0.001 price against the category, on-chain traction measured. Each of those is measured, and each is published in full below.

The score comes from our own monitoring, never from reviews, operator claims, or a language model: reliability, x402 compliance, price against the category, a deterministic risk flag, and a small on-chain traction term, weighted by ranking generation 3. It is not placement anyone can buy: the paid verify tier is reported beside it and is not one of its inputs. Every component below stays published and read-only.

Bands on the 0 to 100 measured score: strong at 93 and above, solid from 75, mixed from 55, weak below 55. Price and speed are scored against the whole category field, every listing in it that carries no danger flag, the scored service included, so the score places a service in its own field.

It is a score inside Verification, and only there: price and speed are scored against the whole category field, every listing in it that carries no danger flag, the scored service included, which here means 138 listings, this one among them: the same 138 the position above is counted against. When the two differ, the field is the wider one, because a listing we have measured too little of to rank still sits in the field the price and the speed are normalized over. The same service in a different field would read differently. The same engine answers GET /api/v1/best, and asked for a different pool (the whole directory, or another filter) it returns a different number for this service under this same ranking generation. Neither is more correct: they answer different questions, and the methodology states which is which.

Traction is a conservative undercount.

All measured facts

What it does

Checks x402 endpoints before an AI agent pays them: a $0.001 pre-payment check (go / caution / no_go, payout address screened against OFAC), a $0.01 full diagnosis with a fix hint per check, the fix as code, and a $0.25 paid delivery check that buys the endpoint once. Pay in USDC on Base, Solana or Algorand, or RLUSD on the XRP Ledger.

x402 Doctor is a listed x402 Verification API. Captured payment terms name Base, Solana. Monitoring and settlement figures below describe the observations available to this directory; an unpaid HTTP 402 check does not prove that a paid call will deliver.

Assessment computed at . Latest service check observed at . Service data JSON · Measurement methodology.

Page rendered at . This response time is separate from the observation and computation times attached to each measurement.

Latest endpoint observation: . Latest price capture: . Prices are recorded quotes, not a promise of availability. Token assets and payment terms are listed separately. Endpoint data JSON · Price history JSON · Measurement methodology.

Assessment computed at . Uptime uses the stated daily-rollup window; response times are in milliseconds, compliance is passed/evaluated checks, and traction is a measured settlement floor. The comparison score is out of 100 within this category. Assessment JSON · Measurement methodology.

Observed daily coverage: 2026-09-15 to 2026-10-14 UTC. Daily monitoring and settlement rollups do not expose their computation time; a bucket date is not an update timestamp. Uptime and response JSON · Volume JSON · Buyers JSON · Measurement methodology.

Ranked from the measured category pool, refreshed at most once a minute. The comparison has no persisted computation timestamp; the assessment time above belongs to this service only. Ranking API documentation · Ranking methodology.

x402 List home · Services · Verification

uptime · latest daily rollup
-
uptime 7d
-
uptime 30d
-
uptime 90d
-
response p95
534ms
avg response
534ms
total checks
1

Measured on the unpaid 402 handshake, not the paid call. A service can 402 correctly and still fail after payment.

price (min)
$0.001
price (max)
$0.25
category percentile (min)
p7 in Verification
category percentile (max)
p69 in Verification
endpoints / prices
6 / 5
model
tiered
stability
100%

No deterministic risk flag. Risk fires only on an exact blocklist match, or a reserved-brand name with a mismatched verified payTo. Never from low uptime, a high price, or a model guess.

domain age
-
registrar
-
hosting
custom
domain created
---

Identity facts, not a risk score.

assessment volume 30d
$0.00
exact assessment volume 30d (USD)
0
assessment recorded at (UTC)
2026-10-14T13:53:07.939Z
buyers 30d
0
settlements 30d
0
measured since
--- (start of our harvest window)
last settlement
---
top buyer share
-
top 3 buyers share
-
concentrated volume
no
trend 7d vs 30d
-
networks
eip155:8453, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdpKuc147dw2N9d
volume all-time
$0
settlements all-time
0
median settlement 30d
-
max settlement 30d
-

Assessment volume uses the latest 30d assessment. Over time sums daily address snapshots, rounded to cents and refreshed separately. The two sources can differ in timing, precision and shared-address attribution. Amounts use cents for comparison; known sub-cent values keep up to 12 significant digits. The exact stored assessment value is shown above.

Conservative undercount: only USDC settlements via facilitators we measure are counted. A measured floor, not an estimate.

Top buyer share lowers the on-chain traction part of the ranking score behind this page's verdict and /best, by up to half when one address holds all 30d volume. The Recommended and Highest volume sorts of the services list do not use it; they use the Concentrated volume rule instead.

member since
2026-10-14
Recent checks
Latest 14 unpaid HTTP checks, newest first; response times in milliseconds, observation times in UTC
Checked at (UTC)StatusHTTPResponseEndpoints
Online402402ms6
Online402478ms6
Online402276ms6
Online402360ms6
Online402463ms6
Online402403ms6
Online402316ms6
Online402355ms6
Online402256ms6
Online402261ms6
Online402395ms6
Online402351ms6
Online402399ms6
Online402534ms6

Changes0 in 30d

No changes recorded in the last 30 days.

all changes

Over time

On-chain volume daily snapshots, USD 30d: $0.00, peak $1.05 on 09-27
volume
Distinct buyers per dayDistinct buyers per day
Uptime no completed-day data
Volume 30d
$0.00
Uptime
no completed-day data
Daily on-chain settlement volume in US dollars, 2026-09-15 to 2026-10-14; highest day $1.05 on 09-27; distinct buyers per day
More charts
Response time daily average, ms min 373ms, avg 373ms, max 373ms

09-15 to 10-14* UTC

Each series spans only the dates it has data for. Every series is also served as JSON at /api/v1/services/x402-doctor/price, /scores, /volume and /buyers.

Values

* today so far, partial (UTC).

The uptime summary counts completed UTC days only. The strip, readouts and table retain today's partial reading.

Daily snapshot total, 30d: $6.22, peak $1.05 on 09-27. The visible 30d total in Traction comes from the latest assessment. These sources can differ in their window, refresh time, cent rounding and shared-address attribution.

Daily address snapshots: 2026-09-15 to 2026-10-14 UTC; * today so far, partial (UTC). Daily snapshots store cents. A recorded $0.00 with settlements cannot distinguish exact zero from volume rounded away. Lost precision is unavailable here. † marks a recorded $0.00 with settlements.

Settlement volume uses the stored USD valuation of tracked payments; it is distinct from token quantities. USD-pegged assets are valued at 1 USD per token in these rollups. The measured settlement floor does not cover all payments to this service.

Assessment history last recorded at . Each UTC day uses its last recorded run; missing readings stay unmeasured. Assessment history JSON · Measurement methodology.

Daily values, 2026-09-21 to 2026-10-14: address settlement volume in USD, distinct buyer and settlement counts, uptime percent, average response milliseconds, compliance passed/total, price percentile 0-100, site signals out of 6; UTC dates
DayVolumeBuyersSettlementsUptimeResponseCompliancePrice percentileSite signals
2026-09-21$0.1011no datano datano datano datano data
2026-09-22$0.0623no datano datano datano datano data
2026-09-23$0.0112no datano datano datano datano data
2026-09-24$0.4828no datano datano datano datano data
2026-09-25$0.9238no datano datano datano datano data
2026-09-26$1.00137no datano datano datano datano data
2026-09-27$1.05215no datano datano datano datano data
2026-09-28$0.66314no datano datano datano datano data
2026-09-29$0.18416no datano datano datano datano data
2026-09-30$0.00 recorded†25no datano datano datano datano data
2026-10-01$0.0725no datano datano datano datano data
2026-10-02$0.0124no datano datano datano datano data
2026-10-03$0.00 recorded†23no datano datano datano datano data
2026-10-04$0.84322no datano datano datano datano data
2026-10-05$0.0135no datano datano datano datano data
2026-10-06$0.1023no datano datano datano datano data
2026-10-07$0.05611no datano datano datano datano data
2026-10-08$0.35415no datano datano datano datano data
2026-10-09$0.00 recorded†12no datano datano datano datano data
2026-10-10$0.0134no datano datano datano datano data
2026-10-11$0.0233no datano datano datano datano data
2026-10-12$0.2735no datano datano datano datano data
2026-10-13$0.00 recorded†12no datano datano datano datano data
2026-10-14*$0.0325100%372.85ms14/14p73/6

Alternatives in Verification

scvd.store · evidence observatory for the x402 economy strong 93/100 100% up 30d $284.61 30d
Rubric Protocol · Post-Quantum AI Attestation solid 93/100 99.8% up 30d $30.95 30d
Limitguard solid 89/100 100% up 30d $13.30 30d
767-2676.com - POPCORN solid 89/100 100% up 30d $0.16 30d
KushBitx AgentProof solid 89/100 100% up 30d $1.52 30d

5 of 137 other ranked services in Verification, ordered by the same measured score.

Own this service?

Keep this listing accurate. Ownership is proven with a domain check and every change is reviewed by hand.

Update this listing

Earn the verified tier: x402list pays a real call to this endpoint and, if it delivers, the service is delivery-verified. The fee covers the cost of the probe, not the badge; there is no refund if the call does not deliver. Agent and API only, no in-browser signing. See /api.

Verify this service ($0.25)
Embed a badge

HTML

<a href="https://x402-list.com/services/x402-doctor?utm_source=badge&utm_medium=referral&utm_campaign=embed">
  <img src="https://x402-list.com/badge/x402-doctor.svg" alt="x402 Doctor listed on x402-list" height="28">
</a>

Markdown

[![x402 Doctor on x402-list](https://x402-list.com/badge/x402-doctor.svg)](https://x402-list.com/services/x402-doctor?utm_source=badge&utm_medium=referral&utm_campaign=embed)

HTML, live uptime variant

<a href="https://x402-list.com/services/x402-doctor?utm_source=badge&utm_medium=referral&utm_campaign=embed">
  <img src="https://x402-list.com/badge/x402-doctor.svg?data=uptime" alt="x402 Doctor uptime on x402-list" height="28">
</a>
Delisting

To request delisting, email info@x402-list.com or update your listing at /services/x402-doctor/update.