ToolAssay

x402 Doctor

x402 Doctor: why a payment failed, in plain words: the cause, whose side it is on (your client, your wallet, the network, the seller or the facilitator) and how to fix it, from over 40 named causes (x402 and Coinbase facilitator codes, EVM and Solana, HTTP and network errors). Send the seller 402 as challenge and the error as response, by POST JSON or GET query. Unknown failures are reviewed nightly.

Not tested: has real-world effectsour last check, 2026-09-30
0 of 0checks answered this week
n/amedian answer time
$0.005listed price per call
n/aprice it asked us

Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.

Endpoint

GET https://api.maxwellinternational.ai/v1/doctor/payment

CategoryMarket data
Provider hostapi.maxwellinternational.ai
Networkseip155:8453, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp
Payment schemesexact
Self-reported calls, 30 days5 from 1 payers (the provider's figure, not ours)

Our checks, last 30 days

We never call tools that send, buy, move money or file anything, not even without paying.

Example input (from the provider)

{
  "method": "GET",
  "queryParams": {
    "challenge": "402",
    "response": "{\"invalidReason\":\"invalid_exact_evm_payload_signature\"}",
    "url": "https://example.com/api"
  },
  "type": "http"
}

Promised output schema (from the provider)

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "input": {
      "additionalProperties": false,
      "properties": {
        "headers": {
          "additionalProperties": {
            "type": "string"
          },
          "type": "object"
        },
        "method": {
          "enum": [
            "GET",
            "HEAD",
            "DELETE"
          ],
          "type": "string"
        },
        "queryParams": {
          "additionalProperties": {
            "type": "string"
          },
          "type": "object"
        },
        "type": {
          "const": "http",
          "type": "string"
        }
      },
      "required": [
        "type",
        "method"
      ],
      "type": "object"
    },
    "output": {
      "properties": {
        "example": {
          "type": "object"
        },
        "type": {
          "type": "string"
        }
      },
      "required": [
        "type"
      ],
      "type": "object"
    }
  },
  "required": [
    "input"
  ],
  "type": "object"
}

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