x402 Preflight

Inspect and validate an unfamiliar x402 endpoint before an agent spends USDC. The free inspection tool observes the challenge, price, network, asset, receiver, discovery metadata, CORS, and operational signals without accepting buyer payment credentials. Paid audit and remediation tools require explicit caller-authorized x402 payment. The published mcp-remote install supports discovery and the free inspection tool only; paid calls require a direct x402-compatible client that can approve, sign, and retry the payment. The service is hosted and its implementation is closed-source; the public repository linked below contains the documentation, discovery files, and the published MCP/OpenAPI surface, not the server code.

{
  "mcpServers": {
    "x402-preflight": {
      "url": "https://x402.chikocorp.com/mcp"
    }
  }
}

{
  "type": "object",
  "required": [
    "resource_url"
  ],
  "properties": {
    "method": {
      "enum": [
        "GET",
        "HEAD",
        "POST"
      ],
      "type": "string",
      "default": "GET"
    },
    "resource_url": {
      "type": "string",
      "format": "uri",
      "pattern": "^https://",
      "maxLength": 2048,
      "description": "Public HTTPS x402 resource to inspect without payment credentials."
    },
    "max_price_usd": {
      "type": "number",
      "maximum": 1000000,
      "minimum": 0
    },
    "expected_network": {
      "type": "string",
      "pattern": "^[a-z0-9]+:[A-Za-z0-9._-]+$",
      "maxLength": 100
    }
  },
  "additionalProperties": false
}

{
  "type": "object",
  "required": [
    "resource_url"
  ],
  "properties": {
    "method": {
      "enum": [
        "GET",
        "HEAD",
        "POST"
      ],
      "type": "string",
      "default": "GET"
    },
    "resource_url": {
      "type": "string",
      "format": "uri",
      "pattern": "^https://",
      "maxLength": 2048,
      "description": "Public HTTPS x402 resource to inspect without payment credentials."
    },
    "max_price_usd": {
      "type": "number",
      "maximum": 1000000,
      "minimum": 0
    },
    "expected_network": {
      "type": "string",
      "pattern": "^[a-z0-9]+:[A-Za-z0-9._-]+$",
      "maxLength": 100
    }
  },
  "additionalProperties": false
}

{
  "type": "object",
  "required": [
    "resource_url",
    "goal"
  ],
  "properties": {
    "goal": {
      "type": "string",
      "maxLength": 800,
      "minLength": 1
    },
    "contact": {
      "type": "string",
      "maxLength": 300
    },
    "language": {
      "type": "string",
      "default": "en",
      "maxLength": 20,
      "minLength": 2
    },
    "constraints": {
      "type": "string",
      "maxLength": 1000
    },
    "callback_url": {
      "type": "string",
      "format": "uri",
      "pattern": "^https://",
      "maxLength": 2000
    },
    "resource_url": {
      "type": "string",
      "format": "uri",
      "pattern": "^https://",
      "maxLength": 500
    },
    "response_format": {
      "enum": [
        "json",
        "markdown",
        "both"
      ],
      "type": "string",
      "default": "both"
    }
  },
  "additionalProperties": false
}