Polkadot RPC Documentation

Polkadot RPC

With Dwellir, you get access to our global Polkadot network which always routes your API requests to the nearest available location, ensuring low latency and the fastest speeds.

Get your API key

Polkadot RPC plans and rate limits

• Free plan: 20 responses per second, up to 100,000 responses a day.
• Plans: $49/mo, $299/mo, $999/mo with 25M, 150M, and 500M included responses. Overages billed at $5/$3/$2 per million responses respectively.
• Paid rate limits: 100 to 5,000 responses per second (bursts from 500 to 10,000), no daily limit.
• Billing: 1 response = 1 API credit on every shared plan, over HTTPS or WebSocket (WSS) where Polkadot supports it.

Details: Pricing · Rate limits · Authentication · Archive nodes

Overview

Polkadot is a next-generation blockchain protocol that connects multiple specialized blockchains into one unified network. Built on the Substrate framework, Polkadot enables cross-chain transfers of any type of data or asset, not just tokens.

This documentation provides comprehensive coverage of Polkadot's JSON-RPC API methods, enabling developers to interact with Polkadot nodes for building applications, wallets, explorers, and other blockchain tools.

Network Information

Mainnet (Polkadot)

Connection Endpoints

Polkadot RPC Endpoints

HTTPShttps://api-polkadot.n.dwellir.com/<your-api-key>

WSSwss://api-polkadot.n.dwellir.com/<your-api-key>

curlJavaScriptPythonGo

curl -sS -X POST https://api-polkadot.n.dwellir.com/<your-api-key> \  -H 'Content-Type: application/json' \  -d '{"jsonrpc":"2.0","method":"chain_getBlockHash","params":[0],"id":1}'

Authentication

Authentication is done via the URL path. Replace {YOUR_API_KEY} with your actual API key obtained from dwellir.com.

API Reference

Browse the core Substrate method groups supported by Polkadot, including system_*, chain_*, state_*, author_*, payment_*, and rpc_methods. Polkadot also exposes grandpa_* and beefy_* where applicable.

Quick Start Examples

Get Latest Block

const response = await fetch('https://api-polkadot.n.dwellir.com/YOUR_API_KEY', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    jsonrpc: '2.0',
    method: 'chain_getBlock',
    params: [],
    id: 1
  })
});

const data = await response.json();
console.log('Latest block:', data.result);

Submit Transaction

import requests
import json

url = "https://api-polkadot.n.dwellir.com/YOUR_API_KEY"
headers = {
    "Content-Type": "application/json"
}

# Properly formatted and signed extrinsic
extrinsic = "0x..."

payload = {
    "jsonrpc": "2.0",
    "method": "author_submitExtrinsic",
    "params": [extrinsic],
    "id": 1
}

response = requests.post(url, headers=headers, data=json.dumps(payload))
tx_hash = response.json()["result"]
print(f"Transaction hash: {tx_hash}")

Subscribe to New Blocks (WebSocket)

const WebSocket = require('ws');

const ws = new WebSocket('wss://api-polkadot.n.dwellir.com/YOUR_API_KEY');

ws.on('open', () => {
  ws.send(JSON.stringify({
    jsonrpc: '2.0',
    method: 'chain_subscribeNewHeads',
    params: [],
    id: 1
  }));
});

ws.on('message', (data) => {
  const response = JSON.parse(data);
  if (response.params?.result) {
    console.log('New block:', response.params.result);
  }
});

Error Handling

Polkadot RPC errors follow the JSON-RPC 2.0 error format:

{
  "jsonrpc": "2.0",
  "error": {
    "code": -32602,
    "message": "Invalid params",
    "data": "Expected hex-encoded hash"
  },
  "id": 1
}

Common Error Codes

Best Practices

1. Connection Management

• Use WebSocket connections for subscriptions and real-time updates
• Implement reconnection logic for WebSocket disconnections
• Use HTTPS for single queries and transactions

2. Error Handling

• Always check for error responses before processing results
• Implement retry logic with exponential backoff
• Log errors for debugging and monitoring

3. Performance Optimization

• Batch multiple queries when possible
• Cache frequently accessed data like metadata
• Use specific block hashes for deterministic queries

4. Security

• Never expose API keys in client-side code
• Validate all input data before submission
• Use secure storage for private keys

SDK Support

Official Libraries

• @polkadot/api - JavaScript/TypeScript SDK
• py-substrate-interface - Python SDK
• subxt - Rust SDK
• go-substrate-rpc-client - Go SDK

Integration Example

// Using @polkadot/api
const { ApiPromise, WsProvider } = require('@polkadot/api');

async function connect() {
  const provider = new WsProvider('wss://api-polkadot.n.dwellir.com/YOUR_API_KEY');

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

  // Query chain data
  const chain = await api.rpc.system.chain();
  console.log(`Connected to ${chain}`);

  return api;
}

Additional Resources

• Polkadot Wiki
• Substrate Documentation
• Polkadot JS Apps
• Network Explorer

Support

For additional support or questions:

• Email: support@dwellir.com
• Documentation: dwellir.com/docs

Method Categories

Select a category below to explore detailed method documentation: