# Vextorium EVM Contract Event Log Decoder

> Vextorium EVM Contract Event Log Decoder is a paid API for AI agents from api.vextorium.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-20).

Fetches and decodes the latest events emitted by an EVM smart contract using a full event signature, returning named parameters, block numbers, and transaction hashes over a configurable trailing block window.

## Facts

- Endpoint: POST https://api.vextorium.com/eventos-contrato-pago?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/vextorium-evm-contract-event-log-decoder-f65d5c86
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_P8LcWqXR65_1OWwb2XewO

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 vextorium-evm-contract-event-log-decoder-f65d5c86 -d '<json body>'
```

Example prompt: Pull the last 100 Transfer events from the USDC contract at 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base using the signature Transfer(address indexed from,address indexed to,uint256 value), looking back 2000 blocks — I want the decoded from/to/value fields plus the transaction hashes.

## When to prefer this

Choose this endpoint when you need decoded, human-readable event logs from an EVM smart contract on Base, Ethereum, Arbitrum, Optimism, or Polygon, especially when you have the full Solidity event signature with indexed markers and want named parameters back. Prefer it over raw RPC eth_getLogs calls when you want automatic ABI decoding and a simple REST interface. Best for monitoring recent activity (up to 5000 blocks back) rather than deep historical queries.

## Known failure modes

- Missing required fields (contrato or evento) returns a validation error
- Invalid or unrecognized event signature causes empty results or decoding failure
- Contract address not deployed on specified network returns zero events
- Block lookback exceeding 5000 or below 10 is clamped or rejected
- Network enum value not in [base, ethereum, arbitrum, optimism, polygon] causes error
- Payment failure (x402 protocol) results in 402 response before processing
- Rate limits or RPC node timeouts may cause partial or failed responses

## How this service works

Latest events emitted by an EVM contract from the event signature (e.g. Transfer(address indexed from,address indexed to,uint256 value)), decoded with parameter names, block and transaction hash, over the last N blocks.

## Output

Returns a JSON object containing: the network name, contract address, the event signature used, the keccak256 topic0 hash, a list of decoded event objects each with transaction hash, block number, and named parameter values (e.g. from/to/value for Transfer events), plus total events found and total blocks scanned. A nota field may include caveats about dynamic parameter encoding.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "red": {
   "enum": [
    "base",
    "ethereum",
    "arbitrum",
    "optimism",
    "polygon"
   ],
   "type": "string"
  },
  "evento": {
   "type": "string",
   "description": "Event signature with indexed markers and names"
  },
  "limite": {
   "type": "integer",
   "description": "Events (1-200, default 50)"
  },
  "bloques": {
   "type": "integer",
   "description": "Blocks back (10-5000, default 2000)"
  },
  "contrato": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "red": "base",
  "nota": "Los valores dinámicos (string/bytes no indexados) se devuelven como palabra cruda.",
  "evento": "Transfer(address,address,uint256)",
  "topic0": "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
  "eventos": [
   {
    "hash": "0x359530c6c0662f964433082b08488f565b893a9c54083a6edb12b3e04a8333d5",
    "bloque": 52083754,
    "valores": {
     "to": "0x41D4934322f2bd6fE1dbe4124070FE61651A2067",
     "from": "0x61040E143A77F165Ba44543AF4A079F2C809D14b",
     "value": "83126144588"
    }
   },
   {
    "hash": "0x48d57ad6140d5c2a949f7ce0dcdfff54cc13f75010a762428c9080f0ac26e5fe",
    "bloque": 52083754,
    "valores": {
     "to": "0xb2cc224c1c9feE385f8ad6a55b4d94E92359DC59",
     "from": "0x787fD1dc3b533171781e4Ae1A563c1AC7b4435E4",
     "value": "149022949510"
    }
   },
   {
    "hash": "0xf6157f9dbc08e8427847ed3057d38b0e867a5a1d1ff3a3c2370f0764f6e80b51",
    "bloque": 52083754,
    "valores": {
     "to": "0x8A8e4170C09074b109352190d47e54d7c1F61e4E",
     "from": "0xB9a6eC042dA44553a7f7F0B4Cb86EdBD91D1D8f8",
     "value": "78574732"
    }
   }
  ],
  "contrato": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "encontrados": 1957,
  "bloques_revisados": 20
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/vextorium-evm-contract-event-log-decoder-f65d5c86/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.vextorium.com](https://www.zero.xyz/host/api.vextorium.com/llms.txt)