ToolVet
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Contracts Selectors

by TraceFast in Onchain & crypto

x402 APIPassing, checked 4 h ago

TraceFast live Ethereum data: the 4-byte function selectors found in a contract's bytecode, each resolved to a known signature and name where one exists, with how many known signatures share the selector. `decodeStatus` says how confident each resolution is. Path address: The contract address, `0x`-prefixed, 40 hex characters, any case. Docs: https://docs.tracefast.xyz/api/contract-selectors.md

GET
https://mpp.tracefast.xyz/api/v1/chains/1/contracts/:address/selectors
Price
$0.005
per call in USDC
Uptime
100%
last 30 days
Response time
289 ms
648 ms slowest 5%
Last check
Passed
4 h ago, next any minute now

Run a free test callHow to call it

Reliability

All checks passedSome failedAll failedNot checked

Status and outage history · Atom feed · Watch with other listings

How to call it

GET https://mpp.tracefast.xyz/api/v1/chains/1/contracts/:address/selectors

Each call costs $0.005 in USDC on Base, paid with the request over x402.

Run a free test callOne unpaid request, the way an agent sends it. You see the payment challenge it gets back. Nothing is charged.

Example request

From the listing.

GET https://mpp.tracefast.xyz/api/v1/chains/1/contracts/:address/selectors

Example response

The provider's example. We can't check it without paying.

{
  "data": {
    "address": "0xdac17f958d2ee523a2206206994597c13d831ec7",
    "chainId": 1,
    "codeHash": "0xb44fb4e949d0f78f87f79ee46428f23a2a5713ce6fc6e0beb3dda78c2ac1ea55",
    "selectorCount": 36,
    "selectors": [
      {
        "candidateCount": 1,
        "decodeStatus": "partial",
        "name": "pause",
        "selector": "0x8456cb59",
        "signature": "pause()"
      }
    ]
  }
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.005.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://mpp.tracefast.xyz/api/v1/chains/1/contracts/:address/selectors'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://mpp.tracefast.xyz/api/v1/chains/1/contracts/:address/selectors' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode
JavaScript: pay and call
// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.005 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.005" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.005 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fmpp.tracefast.xyz%2Fapi%2Fv1%2Fchains%2F1%2Fcontracts%2F%3Aaddress%2Fselectors
const res = await pay("https://mpp.tracefast.xyz/api/v1/chains/1/contracts/:address/selectors");
console.log(res.status, await res.text());
Python: pay and call
# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.005 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.005"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://mpp.tracefast.xyz/api/v1/chains/1/contracts/:address/selectors")
    print(res.status_code, res.text)

Security scan

No findings

We scan names, descriptions and tool definitions for hidden instructions and other prompt-injection patterns.

Recent checks

WhenResultHTTPTimePrice
4 h agoPassed402142 ms$0.005
8 h agoPassed402127 ms$0.005
12 h agoPassed402437 ms$0.005
17 h agoPassed402614 ms$0.005
21 h agoPassed402283 ms$0.005
Show 10 older checks
25 h agoPassed402162 ms$0.005
29 h agoPassed402205 ms$0.005
34 h agoPassed402425 ms$0.005
38 h agoPassed402575 ms$0.005
42 h agoPassed402463 ms$0.005
45 h agoPassed402271 ms$0.005
2 days agoPassed402153 ms$0.005
2 days agoPassed402499 ms$0.005
2 days agoPassed402648 ms$0.005
3 days agoPassed402367 ms$0.005

History

12 Oct 2026Price changed from $0.01 to $0.005