state_call - Polkadot

Example code for the state_call JSON RPC method. Complete guide on how to use state_call JSON RPC in GetBlock Web3 documentation.

This method executes a runtime API call by name with SCALE-encoded arguments and returns the SCALE-encoded result, at a given block. It exposes runtime APIs not surfaced as dedicated RPC methods.

Parameters

Parameter	Type	Required	Description
name	string	Yes	Runtime API method name, such as Metadata_metadata
bytes	string	Yes	SCALE-encoded call arguments, hex-encoded (0x for none)
at	string	No	Block hash to query at. Defaults to the latest block when omitted

Request

cURL

curl --location --request POST 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{"jsonrpc": "2.0", "method": "state_call", "params": ["AccountNonceApi_account_nonce", "0x0000000000000000000000000000000000000000000000000000000000000000"], "id": "getblock.io"}'

JavaScript

example.js

const response = await fetch('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
        jsonrpc: '2.0',
        method: 'state_call',
        params: ["AccountNonceApi_account_nonce", "0x0000000000000000000000000000000000000000000000000000000000000000"],
        id: 'getblock.io'
    })
});

const data = await response.json();
console.log(data.result);

Python

example.py

import requests

response = requests.post(
    'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/',
    headers={'Content-Type': 'application/json'},
    json={
        'jsonrpc': '2.0',
        'method': 'state_call',
        'params': ["AccountNonceApi_account_nonce", "0x0000000000000000000000000000000000000000000000000000000000000000"],
        'id': 'getblock.io'
    }
)

print(response.json()['result'])

Response

{
    "id": "getblock.io",
    "jsonrpc": "2.0",
    "result": "0xd2040000"
}

Response Parameters

Parameter	Type	Description
id	string	Request identifier matching the request
jsonrpc	string	JSON-RPC protocol version ("2.0")
result	string	SCALE-encoded result of the runtime call, hex-encoded

Use Cases

• Runtime APIs: Call runtime APIs like fee or nonce queries

• Advanced Reads: Access logic not exposed as a named RPC

• Fee Computation: Invoke TransactionPaymentApi methods

• Custom Runtimes: Call parachain-specific runtime APIs

Error Handling

Error Code	Message	Description
-32602	Invalid params	A parameter is missing or has the wrong type or format
-32601	Method not found	The method is not available on this endpoint
-32603	Internal error	The node failed to process the request

Library Integration

The idiomatic way to call Polkadot RPC is the Polkadot.js API (@polkadot/api), which connects over WebSocket and exposes the method as api.rpc.state.call.

polkadot-js.js

import { ApiPromise, WsProvider } from '@polkadot/api';

const provider = new WsProvider('wss://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/');
const api = await ApiPromise.create({ provider });

const result = await api.rpc.state.call('AccountNonceApi_account_nonce', '0x...');
console.log(result.toHuman());