{
  "kind": "negative",
  "name": "exact additive transaction missing challenge",
  "schema": "https://kaspa-x402.org/schemas/payment-payload.schema.json",
  "value": {
    "x402Version": 2,
    "accepted": {
      "scheme": "exact",
      "network": "kaspa:testnet-10",
      "amount": "20000000",
      "asset": "KAS",
      "payTo": "kaspatest:ppakk4efunamcdw5uqglluwam94r747ftxdcyw423rx8rdyx9w4r78eljka3q",
      "maxTimeoutSeconds": 60,
      "extra": {
        "binding": "kaspa-exact-v2",
        "profile": "additive",
        "finality": "accepted",
        "transactionEncoding": "kaspa-sdk-safe-json-v2.0.0",
        "payToScriptPublicKey": "0000aa207b6b5729e4fbbc35d4e011fff1ddd96a3f57c9599b823aaa88cc71b4862baa3f87",
        "templateId": "kaspa-x402-kip10-additive-v1",
        "headId": "9090909090909090909090909090909090909090909090909090909090909090",
        "headVersion": "0",
        "expectedHeadOutpoint": {
          "txid": "7171717171717171717171717171717171717171717171717171717171717171",
          "index": 0
        },
        "headAmount": "100000000",
        "headScriptPublicKey": "0000aa207b6b5729e4fbbc35d4e011fff1ddd96a3f57c9599b823aaa88cc71b4862baa3f87",
        "headRedeemScript": "632056b328b30c8bf5839e24058747879408bdb36241dc9c2e7c619faa12b2920967ac67b9bfb9c388b9c2048096980094b9bea268",
        "additiveThresholdSompi": "10000000",
        "challengeId": "9191919191919191919191919191919191919191919191919191919191919191",
        "challengeExpiresAt": "2099-01-01T00:00:00.000Z",
        "paymentOutputIndex": 0
      }
    },
    "payload": {
      "type": "exact-transaction",
      "profile": "additive",
      "transaction": "{\"transaction\":\"signed-kip10-additive\"}",
      "transactionEncoding": "kaspa-sdk-safe-json-v2.0.0",
      "paymentOutputIndex": 0,
      "requestHash": "9292929292929292929292929292929292929292929292929292929292929292",
      "authorization": {
        "version": "kaspa-x402-exact-request-authorization-v1",
        "inputIndex": 1,
        "expiresAt": "2099-01-01T00:00:00.000Z",
        "digest": "9393939393939393939393939393939393939393939393939393939393939393",
        "signature": "94949494949494949494949494949494949494949494949494949494949494949494949494949494949494949494949494949494949494949494949494949494"
      }
    }
  },
  "expectedError": "invalid_kaspa_x402_payload",
  "expectedMissingProperty": "challengeId"
}