Common RPC methods & examples

Common JSON-RPC methods, with cURL, wscat and @polkadot/api examples.

Common EVM RPC Methods

Once your endpoints are generated, you can interact with the network using standard JSON-RPC methods. Here is a quick reference for the most common methods you will use when building your project:

Category	Method	Description
Account Info	eth_getBalance	Returns the native token balance of an address (e.g., LSK or ETH).
	eth_getTransactionCount	Returns the nonce of an account (essential for sending transactions).
Chain State	eth_chainId	Returns the specific Chain ID (e.g., Lisk Mainnet is 1135).
	eth_gasPrice	Returns the current price of gas on the network in wei.
Transaction Info	eth_getTransactionByHash	Gets the full details of a transaction using its unique hash.
	eth_getTransactionReceipt	Gets the receipt (status, logs, gas used) of a transaction.
Contract Interaction	eth_call	Executes a “read-only” call to a smart contract (costs zero gas).
	eth_estimateGas	Estimates how much gas a transaction will cost before you send it.
Events & Logs	eth_getLogs	Returns an array of all logs matching a specific filter (highly useful for indexing data).

Practical Examples

Connect via a command line

You can connect to the network using WebSocket or HTTP with your API key in two ways:

• Adding the API key as a query string ?api_key=${APIKEY}
• Or the request header -H 'authorization: APIKEY ${APIKEY}'

cURL

For example, the following cURL command can be used to get the header and body of a block.

curl -H "Content-Type: application/json" -H "authorization: APIKEY xxxx" -d '{"id":1, "jsonrpc":"2.0", "method": "eth_getBlockByNumber", "params": ["latest", true]}' https://lisk.rpc.blockops.network/rpc

What Success Looks Like: Here is the successful JSON response you will receive back, proving your app is communicating with the chain:

{"jsonrpc":"2.0","result":{"hash":"0x381dd358f0b1e328e861822b2a51a72e8dc064803a5c7ccc96277da3b16d7667","number":"0xe07a1d", "timestamp": "0x65123abc"},"id":1}

wscat

If you want to send data requests with WebSockets, you can use several libraries or wscat. You can install and use wscat as follows:

• Download wscat from https://www.npmjs.com/package/wscat
• Install wscat by running the following command: npm install -g wscat

You can connect to the network with wscat using two options. With the request header:

wscat -c 'wss://lisk.rpc.blockops.network/ws' --header 'authorization: APIKEY xxxx'

Or by adding the API key as a query string:

wscat -c 'wss://lisk.rpc.blockops.network/ws?api_key=**********************'

After executing the command, the terminal will display a message indicating that the connection has been enabled successfully:

Connected (press CTRL+C to quit)

Then, you can send the following request into the open terminal:

> {"id":1, "jsonrpc":"2.0", "method": "eth_blockNumber"}

Response from network node

Connect via Polkadot JS API

If you are building on Polkadot or any Substrate-based chain, you can connect your application using the official @polkadot/api library.

First, install the library in your project repository:

npm install @polkadot/api

Then, instantiate the WsProvider using your Blockops WSS endpoint. The most reliable way to authenticate is by appending your API key as a query parameter in the URL.

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

async function connectToBlockops() {
  const WSS_URL = "wss://polkadot.rpc.blockops.network/ws?api_key=YOUR_API_KEY";

  const wsProvider = new WsProvider(WSS_URL);

  try {
    const api = await ApiPromise.create({ provider: wsProvider });

    const chain = await api.rpc.system.chain();
    const lastHeader = await api.rpc.chain.getHeader();

    console.log(`Successfully connected to ${chain}!`);
    console.log(`Latest Block Number: ${lastHeader.number.toHuman()}`);
  } catch (error) {
    console.error("Connection failed:", error);
  }
}

connectToBlockops();