# Base Transaction Decoder & USDC Payment Verifier

> Base Transaction Decoder & USDC Payment Verifier is a paid API for AI agents from kr-x402-mvp.kgy5612.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-31).

Decodes a Base blockchain transaction by hash, returning method, status, gas, transfers, and x402 USDC payment verification details.

## Facts

- Endpoint: GET https://kr-x402-mvp.kgy5612.workers.dev/v1/tx-decoding?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-transaction-decoder-usdc-payment-verifier-a4f4c77e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_q7CC6JKOQUGhmfUQhE5Nm

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 base-transaction-decoder-usdc-payment-verifier-a4f4c77e
```

Example prompt: Can you decode Base transaction 0x3ea6d07f7e990ba4c2289487cd12ea41b6e13b48518fa38b24de2afd1df1d8ca and confirm whether 0.002 USDC was successfully received by address 0xe4be4d0bd82d8e68203deff81f79ede0529f2617?

## When to prefer this

Use this endpoint when you need to decode and verify a specific Base blockchain transaction, especially to confirm x402 USDC micropayment settlements. It is purpose-built for on-chain payment verification workflows where you need to validate that a specific payee received a specific USDC amount. Prefer it over general block explorers when you need structured JSON output ready for agent consumption, or when checking whether an API payment went through before proceeding with a workflow.

## Known failure modes

- Invalid tx hash format (must be 0x + 64 hex chars) — returns validation error
- Transaction not found on Base — returns 404 or empty result
- Transaction still pending — confirmations may be 0 or status unclear
- Payment verification fails if expect_to/expect_usdc don't match actual transfers
- x402 micropayment not included or rejected — endpoint returns 402 before serving data

## How this service works

Pay-per-call crypto microdata for trading/onchain AI agents via x402 (USDC on Base): Base gas, token risk, balances, multi-venue prices, Hyperliquid book/funding, kimchi premium. No API keys.

## Output

Returns a JSON object with the transaction hash, block number, timestamp, chain, status (success/fail), contract method called, gas used, ETH fee, ETH value, number of confirmations, full token transfer list (from/to/token/amount/symbol), USDC received map per address, and boolean flags for payment_verified and is_x402_settlement.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "hash"
     ],
     "properties": {
      "hash": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{64}$",
       "examples": [
        "0x3ea6d07f7e990ba4c2289487cd12ea41b6e13b48518fa38b24de2afd1df1d8ca"
       ],
       "description": "Base tx hash"
      },
      "expect_to": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$",
       "description": "Optional: payee you expect to receive USDC"
      },
      "expect_usdc": {
       "type": "number",
       "minimum": 0,
       "description": "Optional: minimum USDC amount expected (with expect_to)"
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "to": "0xca11bde05977b3631167028862be2a173976ca11",
  "from": "0xc6699d2aada6c36dfea5c248dd70f9cb0235cb63",
  "hash": "0x3ea6d07f7e990ba4c2289487cd12ea41b6e13b48518fa38b24de2afd1df1d8ca",
  "block": 53220068,
  "chain": "base",
  "method": "aggregate3 (Multicall3)",
  "status": "success",
  "fee_eth": 6.5e-7,
  "gas_used": 92312,
  "timestamp": "2026-10-28T23:18:03Z",
  "transfers": [
   {
    "to": "0xe4be4d0bd82d8e68203deff81f79ede0529f2617",
    "from": "0xa1d1c0cf717402ff3651aa4873ccf96410b01978",
    "token": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": 0.002,
    "symbol": "USDC"
   }
  ],
  "value_eth": 0,
  "confirmations": 21764,
  "usdc_received": {
   "0xe4be4d0bd82d8e68203deff81f79ede0529f2617": 0.002
  },
  "payment_verified": true,
  "is_x402_settlement": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-transaction-decoder-usdc-payment-verifier-a4f4c77e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from kr-x402-mvp.kgy5612.workers.dev](https://www.zero.xyz/host/kr-x402-mvp.kgy5612.workers.dev/llms.txt)