{
  "kind": "negative",
  "name": "exact-transaction missing transaction artifact",
  "schema": "https://kaspa-x402.org/schemas/kaspa-payment-payload.schema.json",
  "value": {
    "type": "exact-transaction",
    "transactionEncoding": "kaspa-sdk-safe-json-v2.0.0",
    "paymentOutputIndex": 0
  },
  "expectedError": "invalid_kaspa_x402_payload"
}