ToolVet
82trust / 100

Selector Lookup

by Function selector / event topic in Onchain & crypto

x402 APIPassing, checked 3 h ago

Resolve a 4-byte function selector or a 32-byte event topic hash to its known human-readable Solidity signatures, via the openchain.xyz signature database with 4byte.directory as fallback. Unknown selectors return {found:false} with an empty list, not an error.

POST https://agent402.tools/api/selector-lookup

Last 30 days

All checks passedSome failedAll failedNot checked
Uptime
100%
Response time
187 ms typical, 187 ms slowest 5%
Last check
3 h ago
Next check
any minute now

How to call it

# See the payment challenge (nothing is charged)
curl -i -X POST "https://agent402.tools/api/selector-lookup" \
  -H "content-type: application/json" \
  -d '{"selector":"0xa9059cbb"}'
import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { ExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const client = new x402Client().register(
  "eip155:8453",
  new ExactEvmScheme(privateKeyToAccount(process.env.AGENT_KEY)),
);
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? Preflight it first for $0.005:
// GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fagent402.tools%2Fapi%2Fselector-lookup
const res = await pay("https://agent402.tools/api/selector-lookup", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({"selector":"0xa9059cbb"}),
});
console.log(await res.json());

Example input

{
  "selector": "0xa9059cbb"
}

Example output

{
  "found": true,
  "kind": "function",
  "selector": "0xa9059cbb",
  "signatures": [
    "transfer(address,uint256)"
  ],
  "source": "openchain.xyz"
}

Security scan

  • No findings. We scan names, descriptions and tool definitions for hidden instructions and other prompt-injection patterns.

Recent checks

WhenResultHTTPTimePrice
3 h agoPassed402240 ms$0.002
8 h agoPassed402187 ms$0.002