Read-only JSON-RPC passthrough

Escape hatch for power users: forward an arbitrary read-only JSON-RPC method to the chain. Method must be in our read-only whitelist (eth_call, eth_getLogs, eth_getBlockByNumber, eth_getTransactionReceipt, eth_chainId, eth_blockNumber, etc.). Mutating methods (eth_sendTransaction, eth_sendRawTransaction) are rejected — sign and broadcast through your own provider.

Input

Field	Type	Description
method *	string	JSON-RPC method (must be in the read-only whitelist).
params	array	JSON-RPC parameter array (often empty for simple methods).
network	string	ethereum / base / polygon / arbitrum / optimism (default base).

Example output

{
  "network": "base",
  "method": "eth_blockNumber",
  "result": "0x1234567"
}

Try it — see the 402 challenge (free)

curl -i -X POST https://agent402.tools/api/eth-call \
  -H "Content-Type: application/json" \
  -d '{"method":"eth_blockNumber","params":[],"network":"base"}'

The response is HTTP 402 Payment Required with exact payment requirements. Any x402 v2 client pays automatically and retries:

Paid call (JavaScript agent)

import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const client = new x402Client();
registerExactEvmScheme(client, { signer: privateKeyToAccount(KEY) });
const payFetch = wrapFetchWithPayment(fetch, client);

const res = await payFetch("https://agent402.tools/api/eth-call", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    "method": "eth_blockNumber",
    "params": [],
    "network": "base"
  }),
});

Wallet-only. This tool reaches the network/browser/storage, so it is paid in USDC via x402 (no proof-of-work tier).

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