# Base Transaction Lookup

> Base Transaction Lookup is a paid API for AI agents from onchaincheck.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-29).

Returns a human-readable summary of a Base blockchain transaction including status, block info, sender/recipient, ETH value, gas fees, method selector, and decoded ERC-20 token transfers.

## Facts

- Endpoint: GET https://onchaincheck.dev/base/tx?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-transaction-lookup-fa888025
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oFAJbhWOEfaFYVvQ7GVKO

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-lookup-fa888025
```

Example prompt: Can you pull up the details for Base transaction 0xff80142e4591e95e4088a7f37838e359843151633209f62a3b39f85402cc7d06 — I want to see if it succeeded, how much ETH moved, what token transfers happened, and what gas fee was paid?

## When to prefer this

Use this endpoint when you need a complete, human-readable breakdown of a specific Base transaction — especially when you need decoded ERC-20 transfer details with token symbols and amounts, which raw RPC calls don't provide out of the box. Prefer this over raw ethers.js or web3 calls when you need decoded token transfers without writing ABI parsing logic, or over block explorers when you need structured JSON output rather than a webpage.

## Known failure modes

- Invalid transaction hash format (not matching 0x + 64 hex chars) returns a validation error
- Transaction hash not found on Base returns a not-found error
- Pending or unconfirmed transactions may not return complete data
- Token symbols for unverified contracts may be missing or null
- Rate limits or upstream RPC issues may cause 5xx errors

## How this service works

Human-readable summary of a Base transaction: status, block and time, sender and recipient, ETH value, gas used and fee, method selector, and decoded ERC-20 transfers with token symbols and amounts.

## Output

A JSON object containing the transaction hash, chain, status (success/fail), block number, ISO timestamp, sender address, recipient address, ETH value transferred, gas used, gas fee in ETH, method selector (4-byte), and an array of decoded ERC-20 token transfers each with from/to addresses, token contract address, symbol, human-readable amount, and raw amount.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "hash"
     ],
     "properties": {
      "hash": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{64}$",
       "description": "Transaction hash on Base"
      }
     },
     "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": "0xd6145b2D3F379919E8CdEda7B97e37c4b2Ca9c40",
  "fee": "0.000001440003084728",
  "from": "0xf87F67497C535f856670518a3577b2bfC1bEE976",
  "hash": "0xff80142e4591e95e4088a7f37838e359843151633209f62a3b39f85402cc7d06",
  "chain": "base",
  "value": "0.0005",
  "status": "success",
  "gasUsed": 130678,
  "timestamp": "2026-10-22T15:30:13.000Z",
  "blockNumber": 52946833,
  "nativeSymbol": "ETH",
  "methodSelector": "0x3593564c",
  "tokenTransfers": [
   {
    "to": "0xf87F67497C535f856670518a3577b2bfC1bEE976",
    "raw": "1198173",
    "from": "0x1C450D7d1FD98A0b04E30deCFc83497b33A4F608",
    "token": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "1.198173",
    "symbol": "USDC"
   },
   {
    "to": "0x1C450D7d1FD98A0b04E30deCFc83497b33A4F608",
    "raw": "500000000000000",
    "from": "0xd6145b2D3F379919E8CdEda7B97e37c4b2Ca9c40",
    "token": "0x4200000000000000000000000000000000000006",
    "amount": "0.0005",
    "symbol": "WETH"
   }
  ],
  "contractCreated": null
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-transaction-lookup-fa888025/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from onchaincheck.dev](https://www.zero.xyz/host/onchaincheck.dev/llms.txt)