ToolVet
78trust / 100

Base Eth Call

by agentshelf.syntexa.ch in Onchain & crypto

x402 APIPassing, checked 2 h ago

Call when an agent needs a read-only Base eth_call. Send to and data (hex) or a function signature plus args. Optional from and block. Reverts return a decoded reason. No state change and no spend. Send JSON {"to":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","data":"0x18160ddd"}. Exact $0.004 USDC on Base. Try unpaid POST /v1/sandbox/base-eth-call first.

POST
https://agentshelf.syntexa.ch/v1/base-eth-call
Price
$0.004
per call in USDC
Uptime
100%
last 30 days
Response time
90 ms
90 ms slowest 5%
Last check
Passed
2 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

POST https://agentshelf.syntexa.ch/v1/base-eth-call

Each call costs $0.004 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.

POST https://agentshelf.syntexa.ch/v1/base-eth-call
content-type: application/json

{
  "data": "0x18160ddd",
  "to": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
}

Parameters

ParameterTypeRequiredDescription
argsstringNoJSON array of arguments. Example: ["0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"]. A POST array is accepted. Requires signature.
blockstringNoBlock tag or number for eth_call. latest, finalized, safe, or a non-negative integer. Omit it for latest. The call is read-only.
datastringNoCalldata, 0x hex, at most 2048 characters. Example: 0x18160ddd (totalSupply()). Send data or signature, not both. eth_call cannot change state.
fromstringNoOptional eth_call from address. Example: 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045. It is not a transaction sender and nothing is spent.
signaturestringNoFunction signature. Example: decimals() or balanceOf(address)(uint256). args is a JSON array when the function has parameters. Send signature or data, not both.
tostringYesContract to call on Base. Example: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913. The call is eth_call with no value, so it cannot change state.

Example response

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

{
  "billed": true,
  "block": "latest",
  "data": "0x18160ddd",
  "decoded": null,
  "from": null,
  "network": "eip155:8453",
  "ok": true,
  "receipt_id": "rcpt_01EXAMPLE000000000000000",
  "result": "0x00000000000000000000000000000000000000000000000000000000000f4240",
  "revert_data": null,
  "revert_reason": null,
  "success": true,
  "to": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "warnings": []
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.004.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://agentshelf.syntexa.ch/v1/base-eth-call' \
  -H 'content-type: application/json' \
  --data-raw '{"data":"0x18160ddd","to":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"}'

# 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 - -X POST 'https://agentshelf.syntexa.ch/v1/base-eth-call' \
  -H 'content-type: application/json' \
  --data-raw '{"data":"0x18160ddd","to":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"}' \
  | 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 $0.004 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.004" });
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 $0.004 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fagentshelf.syntexa.ch%2Fv1%2Fbase-eth-call&method=POST
const res = await pay("https://agentshelf.syntexa.ch/v1/base-eth-call", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "data": "0x18160ddd",
    "to": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
  }),
});
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 $0.004 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.004"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://agentshelf.syntexa.ch/v1/base-eth-call",
        json={
            "data": "0x18160ddd",
            "to": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        },
    )
    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
2 h agoPassed40290 ms$0.004