# x402 Base USDC Payment Checker – Full History Deep Scan

> x402 Base USDC Payment Checker – Full History Deep Scan is a paid API for AI agents from paycheck.hectichustle.workers.dev, paid per call via x402, $0.05/call, status unknown (last checked 2026-10-17).

Performs a full funding-history deep scan of a Base USDC payment by tx hash, verifying match, tracing funder provenance, and detecting address-poisoning risks with the x402 Trust Index.

## Facts

- Endpoint: POST https://paycheck.hectichustle.workers.dev/check/deep?utm_source=zero.xyz
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-17
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-base-usdc-payment-checker-full-history-deep-scan-84dba173
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_KjfWRHELqVtLsL0Nj-FoW

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability x402-base-usdc-payment-checker-full-history-deep-scan-84dba173 -d '<json body>'
```

Example prompt: Do a full deep-scan verification on Base USDC transaction 0xabc123...def456 — I need to confirm it paid exactly 1 USDC to 0x509e55c4f898b43c856fb0e51048b1b7bfbc9ede, and I want the complete funding-history scan to see whether the payer was externally funded or self-funded.

## When to prefer this

Choose this endpoint over the standard $0.01 checker when you need complete funding-history provenance (scanned from block 0), address-poisoning detection, x402 Trust Index grades, or when auditing a high-value payment from an unknown counterparty. Use the cheaper /check endpoint for simple tx confirmation of known senders.

## Known failure modes

- Transaction hash not found on Base mainnet — returns found:false with optional EIP-3009 authorization fallback
- Amount or recipient mismatch — returns match.ok:false with specific mismatch fields
- Indexer temporarily unavailable — partial coverage with historyComplete:false
- Invalid tx hash format — schema validation error before processing
- Insufficient x402 payment — 402 response before scan executes
- Rate limiting from underlying RPC providers — delayed or partial response

## How this service works

Did this USDC payment settle, and who funded this wallet (the payer)? Deep Base verification: confirmations, payTo/amount match, fake-token and lookalike warnings, plus the payer's FULL inbound USDC history (no window), top funders, coverage stats and a recheckable sha256 receipt. Not charged if the index is down. Body {txHash, expectedPayTo?, expectedAmount?}.

## Output

Returns a JSON object with: payment match status (payTo and amount), funding verdict (external vs self-funded), top funders with totals, full block coverage stats (from block 0 to chain tip), address-poisoning warnings, number of confirmations, RPC call count, price charged (0.05 USDC), and a human-readable summary string.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "token": {
   "type": "string",
   "description": "Optional (aliases asset, currency): \"USDC\" or the Base USDC contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 (apexfaucet-style). Any other token is a 400 unsupported_token, not charged. Responses always echo token \"USDC\"."
  },
  "txHash": {
   "type": "string",
   "pattern": "^0x[0-9a-fA-F]{64}$",
   "description": "Base mainnet transaction hash"
  },
  "minAmount": {
   "type": [
    "string",
    "number"
   ],
   "description": "Optional floor (aliases min_amount, min): payment must be at least this many USDC; unlike expectedAmount it is not exact"
  },
  "authorization": {
   "type": "object",
   "required": [
    "from",
    "nonce"
   ],
   "properties": {
    "from": {
     "type": "string",
     "pattern": "^0x[0-9a-fA-F]{40}$"
    },
    "nonce": {
     "type": "string",
     "pattern": "^0x[0-9a-fA-F]{64}$"
    },
    "validAfter": {
     "type": [
      "string",
      "integer"
     ]
    },
    "validBefore": {
     "type": [
      "string",
      "integer"
     ],
     "description": "unix seconds"
    }
   },
   "description": "Optional EIP-3009 authorization (x402 exact payload) to check when there is no tx or the tx is not found"
  },
  "expectedPayTo": {
   "type": "string",
   "pattern": "^0x[0-9a-fA-F]{40}$",
   "description": "Expected recipient (full-address, case-insensitive compare)"
  },
  "expectedPayer": {
   "type": "string",
   "pattern": "^0x[0-9a-fA-F]{40}$",
   "description": "Optional expected payer (aliases from, payer): the USDC Transfer's from must equal it"
  },
  "selfAddresses": {
   "type": "array",
   "items": {
    "type": "string"
   },
   "maxItems": 10,
   "description": "Optional: other addresses you control; funding from them counts as self_funded"
  },
  "expectedAmount": {
   "type": [
    "string",
    "number"
   ],
   "description": "Expected USDC amount, decimal (e.g. \"0.01\")"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "mode": "live_paid_deep",
  "block": 52409752,
  "found": true,
  "match": {
   "ok": true,
   "payToMatch": true,
   "amountMatch": true
  },
  "funding": {
   "source": "blockscout",
   "verdict": "external",
   "topFunders": [
    {
     "from": "0x86bafb3916943fbba78e7add6c25a230ec27df44",
     "count": 2,
     "total": "161.651325"
    }
   ],
   "scannedBlocks": {
    "to": 52409752,
    "from": 0,
    "history": "full",
    "complete": true,
    "windowBlocks": 52409753
   }
  },
  "payment": {
   "to": "0x509e55c4f898b43c856fb0e51048b1b7bfbc9ede",
   "from": "0xfc1e390266f3b29179b5d63a7937a689d1e5279a",
   "amount": "1"
  },
  "receipt": {
   "reason": null,
   "recheck": {
    "hash": "0x…",
    "hashAlg": "sha256(canonical JSON, keys sorted, no whitespace)",
    "payload": {
     "v": 2,
     "chain": "eip155:8453",
     "source": "blockscout",
     "blockRange": {
      "to": 52409752,
      "from": 0
     }
    }
   },
   "verdict": "external",
   "rpcCalls": 4,
   "priceCharged": "0.05 USDC",
   "blocksScanned": {
    "to": 52409752,
    "from": 0,
    "complete": true
   }
  },
  "summary": "1 USDC from 0xfc1e… to 0x509e… at block 52409752. Matches expected payment. Payer was funded externally.",
  "coverage": {
   "source": "blockscout",
   "indexer": "blockscout pro (keyed)",
   "complete": true,
   "rpcCalls": 4,
   "windowTo": 52409752,
   "endpoints": [
    "quicknode (keyed)"
   ],
   "windowFrom": 0,
   "coveragePct": 100,
   "indexerPages": 1,
   "windowBlocks": 52409753,
   "blocksCovered": 52409753,
   "getLogsChunks": 0,
   "uniqueFunders": 1,
   "historyComplete": true,
   "inboundTransfers": 2
  },
  "warnings": [],
  "confirmed": true,
  "confirmations": 1200
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-base-usdc-payment-checker-full-history-deep-scan-84dba173/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from paycheck.hectichustle.workers.dev](https://www.zero.xyz/host/paycheck.hectichustle.workers.dev/llms.txt)