rpc_modules - Optimism

Example code for the rpc_modules json-rpc method. Сomplete guide on how to use rpc_modules json-rpc in GetBlock.io Web3 documentation.

This method returns an object listing all available RPC modules and their versions. This is useful for determining which methods are available on a particular node and for debugging connectivity issues.

Parameters

• None

Request Sample

cURL

curl --location 'https://go.getblock.us/<ACCESS_TOKEN>' \
--header 'Content-Type: application/json' \
--data '{
   "jsonrpc": "2.0",
    "method": "rpc_modules",
    "params": []
    "id": "getblock.io"
}'

Axios

import axios from 'axios'
let data = JSON.stringify({
    "jsonrpc": "2.0",
    "method": "rpc_modules",
    "params": [],
    "id": "getblock.io"
};

let config = {
  method: "post",
  maxBodyLength: Infinity,
  url: "https://go.getblock.us/<ACCESS_TOKEN>",
  headers: {
    "Content-Type": "application/json",
  },
  data: data,
};

axios
  .request(config)
  .then((response) => {
    console.log(JSON.stringify(response.data));
  })
  .catch((error) => {
    console.log(error);
  });

Request

import requests
import json

url = "https://go.getblock.us/<ACESS_TOKEN>"

payload = json.dumps({
   jsonrpc": "2.0",
    "method": "rpc_modules",
    "params": []
    "id": "getblock.io"
})
headers = {
  'Content-Type': 'application/json'
}

response = requests.request("POST", url, headers=headers, data=payload)

print(response.text)

Rust

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = reqwest::Client::builder()
        .build()?;

    let mut headers = reqwest::header::HeaderMap::new();
    headers.insert("Content-Type", "application/json".parse()?);

    let data = r#"{
   jsonrpc": "2.0",
    "method": "rpc_modules",
    "params": []
    "id": "getblock.io"
}"#;

    let json: serde_json::Value = serde_json::from_str(&data)?;

    let request = client.request(reqwest::Method::POST, "https://go.getblock.us/<ACCESS_TOKEN>")
        .headers(headers)
        .json(&json);

    let response = request.send().await?;
    let body = response.text().await?;

    println!("{}", body);

    Ok(())
}

Response

A successful response returns the following:

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": {
        "eth": "1.0",
        "net": "1.0",
        "web3": "1.0",
        "debug": "1.0",
        "trace": "1.0"
    }
}

Response Parameters

• id: A unique request identifier, matching the id sent in the request body.

• jsonrpc: Specifies the use of JSON-RPC version 2.0.

• result: An object mapping module names to their version strings.

Use Case

The rpc_modules method is commonly used for:

• Module discovery

• API capability checking

• Debugging

• Infrastructure documentation

Error handling

Status Code	Error Message	Cause
404	Not found	Missing or invalid ACCESS_TOKEN.

Integration with Web3

Using rpc_modules allows developers to:

• Tools adapt automatically based on enabled modules.

• Ensures required RPC namespaces exist before dApp initialization.

• Helps compare feature sets across RPC providers.

Ethers.js

import { ethers } from "ethers";
const RPC_URL = "https://go.getblock.us/<ACCESS_TOKEN>";
const provider = new ethers.JsonRpcProvider(RPC_URL);
async function Call() {
  try {
     const result = await provider.send( "rpc_modules",
[],);    
console.log("The result:", result);
    return result;
  } catch (error) {
    console.error("The error:", error);
    throw error;
  }
}

Viem

import { createPublicClient, http } from 'viem';
import { optimism } from 'viem/chains';

// Create Viem client with GetBlock
const client = createPublicClient({
  chain: optimism,
  transport: http('https://go.getblock.us/<ACCESS_TOKEN>'
});

// Using the method through Viem
async function Call() {
    try {
        // Method-specific Viem implementation
        const result = await client.request({
          method: "rpc_modules",
          params: [
          ],
        });
        console.log('Result:', result);
        return result;
    } catch (error) {
        console.error('Viem Error:', error);
        throw error;
    }
}