# BountyWorth — Base USDC Payment Evidence & x402 Preflight

> BountyWorth — Base USDC Payment Evidence & x402 Preflight is a paid API for AI agents from bountyworth.amber-panda-3101.chatgpt.site, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Verifies a Base USDC transaction hash against on-chain evidence or checks an x402 endpoint's payment challenge, resource binding, CORS exposure, and Bazaar readiness.

## Facts

- Endpoint: GET https://bountyworth.amber-panda-3101.chatgpt.site/api/payment-evidence
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/bountyworth-base-usdc-payment-evidence-x402-preflight-314e45ae
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_AtAzcJYtGRvgMCI8scAwz

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 bountyworth-base-usdc-payment-evidence-x402-preflight-314e45ae
```

Example prompt: Can you verify that Base USDC transaction 0xe2ced59fde0640db029567e63560ecda0783ceb1c668fce7a770d98863ec84e1 was successfully sent to 0x5b1f4ab7ce2c252b44f8d1dd96da47d6bce6fbd0 for exactly 191805636177 atomic units?

## When to prefer this

Choose this endpoint when you need on-chain proof that a specific Base USDC transaction occurred and optionally matched an expected recipient and amount — particularly in x402 payment flows, automated pay-to-access systems, or audit trails requiring cryptographic transaction evidence. It is ideal when you need a structured verdict ('confirmed'/'mismatch'/'failed') rather than raw RPC data.

## Known failure modes

- Invalid or malformed transaction hash (not matching ^0x[a-fA-F0-9]{64}$) returns a validation error
- Transaction not found on Base mainnet returns a failed verdict
- Amount or recipient mismatch returns a 'mismatch' verdict with expectation details
- Network RPC unavailability causes delayed or error response
- Non-USDC token transfer returns a failed or mismatch verdict
- HEAD or DELETE method with missing required parameters returns schema validation error

## How this service works

Verify Base USDC transaction evidence or check an x402 endpoint’s payment challenge, resource binding, CORS exposure, and Bazaar readiness.

## Output

Returns a JSON object with a verdict ('confirmed', 'mismatch', or 'failed'), a boolean paid flag, full transfer details including sender, recipient, USDC amount in both human-readable and atomic units, transaction hash, block number and confirmation count, asset metadata (contract address, symbol, decimals), network info (Base mainnet chain ID 8453), and an evidence object describing the verification method used.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "tx"
     ],
     "properties": {
      "tx": {
       "type": "string",
       "pattern": "^0x[a-fA-F0-9]{64}$",
       "description": "Base transaction hash to verify."
      },
      "expectedTo": {
       "type": "string",
       "pattern": "^0x[a-fA-F0-9]{40}$",
       "description": "Optional expected USDC recipient."
      },
      "expectedAmountAtomic": {
       "type": "string",
       "pattern": "^(0|[1-9][0-9]{0,29})$",
       "description": "Optional expected USDC amount in 6-decimal atomic units."
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "product",
      "paid",
      "network",
      "transaction",
      "asset",
      "transfers",
      "expectation",
      "verdict",
      "evidence"
     ],
     "properties": {
      "paid": {
       "type": "boolean"
      },
      "asset": {
       "type": "object"
      },
      "network": {
       "type": "object"
      },
      "product": {
       "type": "string"
      },
      "verdict": {
       "enum": [
        "confirmed",
        "mismatch",
        "failed"
       ],
       "type": "string"
      },
      "evidence": {
       "type": "object"
      },
      "transfers": {
       "type": "array",
       "items": {
        "type": "object"
       }
      },
      "observedAt": {
       "type": "string",
       "format": "date-time"
      },
      "expectation": {
       "type": "object"
      },
      "transaction": {
       "type": "object"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "paid": true,
  "asset": {
   "symbol": "USDC",
   "contract": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
   "decimals": 6
  },
  "network": {
   "id": "eip155:8453",
   "name": "Base mainnet",
   "chainId": 8453
  },
  "product": "BountyWorth Base USDC Payment Evidence",
  "verdict": "confirmed",
  "evidence": {
   "source": "Base public JSON-RPC transaction receipt",
   "receiptStatusChecked": true,
   "tokenContractChecked": true,
   "sameTransferMatchRequired": true
  },
  "transfers": [
   {
    "to": "0x5b1f4ab7ce2c252b44f8d1dd96da47d6bce6fbd0",
    "from": "0xb2cc224c1c9fee385f8ad6a55b4d94e92359dc59",
    "amountUsdc": "191805.636177",
    "amountAtomic": "191805636177"
   }
  ],
  "expectation": {
   "matched": true,
   "expectedTo": "0x5b1f4ab7ce2c252b44f8d1dd96da47d6bce6fbd0",
   "expectedAmountAtomic": "191805636177"
  },
  "transaction": {
   "hash": "0xe2ced59fde0640db029567e63560ecda0783ceb1c668fce7a770d98863ec84e1",
   "status": "success",
   "blockNumber": "50592330",
   "confirmations": "1"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bountyworth-base-usdc-payment-evidence-x402-preflight-314e45ae/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bountyworth.amber-panda-3101.chatgpt.site](https://www.zero.xyz/host/bountyworth.amber-panda-3101.chatgpt.site/llms.txt)