x402: No version field

A deliberately broken x402 endpoint charging 0.0001 USDC on Base Sepolia, advertising x402.org.

Protocol: x402
Network: Base Sepolia
Price: 0.0001 USDC
Scheme: exact
Facilitator: x402.org
Behavior: No version field

The challenge omits x402Version. A client that assumes a version is guessing.

Your endpointNo version field

/api/x402?quirk=missing-version

Try it

curl -i "https://test402.com/api/x402?quirk=missing-version"

Returns 402 with no x402Version field in the challenge.

Response it will return (HTTP 402)

{
  "error": "PAYMENT-SIGNATURE header is required",
  "resource": {
    "url": "https://test402.com/api/x402?quirk=missing-version",
    "description": "test402 challenge",
    "mimeType": "application/json"
  },
  "accepts": [
    {
      "scheme": "exact",
      "network": "eip155:84532",
      "amount": "100",
      "asset": "0x036CbD53842c5426634e7929541eC2318f3dCF7e",
      "payTo": "0x0000000000000000000000000000000000000402",
      "maxTimeoutSeconds": 300,
      "extra": {
        "name": "USDC",
        "version": "2",
        "assetTransferMethod": "eip3009"
      }
    }
  ],
  "extensions": {
    "https://test402.com/extensions/facilitator": {
      "id": "x402org",
      "url": "https://x402.org/facilitator"
    }
  },
  "note": "test402 scenario. quirk=missing-version"
}