system_properties | Moonriver RPC Docs

Get chain properties on Moonriver including token symbol, decimals, and the address-format prefix when the chain exposes one. Essential for token formatting, wallet configuration, and address handling.

Returns the chain-specific properties for Moonriver, including the native token symbol, token decimals, and the address-format prefix when the chain exposes one. This information is critical for correctly formatting balances, validating addresses, and configuring wallets.

Why Moonriver? Build on the Moonbeam canary network on Kusama for real-world testing of EVM dApps with Moonbeam code ships here first, full EVM compatibility on Kusama, 80% fee burn mechanism, and XCM cross-chain messaging.

When to Use This Method

system_properties is essential for dApp developers testing on Kusama, early adopters, and teams requiring production-ready experimentation:

Token Formatting -- Get the correct decimals and symbol to display human-readable balances on Moonriver
Address Validation -- Retrieve the SS58 prefix to encode and validate addresses for production-grade dApp testing, early feature deployment, and Kusama-based EVM applications
Wallet and dApp Configuration -- Dynamically configure your UI with the correct token symbol, decimals, and address format
Multi-Chain Support -- Automatically adapt your application to different Substrate chains without hardcoding properties

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

async function formatBalance(api, rawBalance) {
  const properties = await api.rpc.system.properties();
  const raw = properties.toJSON();
  const decimalsRaw = raw.tokenDecimals;
  const symbolRaw = raw.tokenSymbol;
  const decimals = Array.isArray(decimalsRaw) ? decimalsRaw[0] : decimalsRaw;
  const symbol = Array.isArray(symbolRaw) ? symbolRaw[0] : symbolRaw;

  const divisor = new BN(10).pow(new BN(decimals));
  const whole = new BN(rawBalance).div(divisor);
  const fractional = new BN(rawBalance).mod(divisor).toString().padStart(decimals, '0');

  return `${whole}.${fractional.slice(0, 4)} ${symbol}`;
}

// Example output depends on the chain's live token symbol and decimals.

2. Dynamic Wallet Configuration

Auto-configure your wallet or dApp based on chain properties:

JavaScript

async function configureWallet(endpoint) {
  const provider = new WsProvider(endpoint);
  const api = await ApiPromise.create({ provider });

  const [chain, properties] = await Promise.all([
    api.rpc.system.chain(),
    api.rpc.system.properties()
  ]);

  const raw = properties.toJSON();
  const symbolsRaw = raw.tokenSymbol;
  const decimalsRaw = raw.tokenDecimals;
  const symbols = Array.isArray(symbolsRaw) ? symbolsRaw : [symbolsRaw];
  const decimals = Array.isArray(decimalsRaw) ? decimalsRaw : [decimalsRaw];
  const ss58Format = raw.ss58Format ?? raw.SS58Prefix ?? null;

  const config = {
    chainName: chain.toString(),
    ss58Format,
    tokens: symbols.map((symbol, idx) => ({
      symbol,
      decimals: decimals[idx] ?? decimals[0],
    }))
  };

  console.log('Wallet configured for:', config.chainName);
  console.log('Native token:', config.tokens[0].symbol, `(${config.tokens[0].decimals} decimals)`);
  console.log('Address format SS58:', config.ss58Format ?? 'not exposed');

  await api.disconnect();
  return config;
}

3. SS58 Address Encoding and Validation

Use the SS58 prefix to properly encode addresses for the target chain:

JavaScript

import { encodeAddress, decodeAddress } from '@polkadot/util-crypto';

async function formatAddressForChain(api, genericAddress) {
  const properties = await api.rpc.system.properties();
  const raw = properties.toJSON();
  const ss58Format = raw.ss58Format ?? raw.SS58Prefix;

  if (ss58Format == null) {
    throw new Error('This chain does not expose an SS58 prefix through system_properties.');
  }

  // Convert any SS58 address to this chain's format
  const publicKey = decodeAddress(genericAddress);
  const chainAddress = encodeAddress(publicKey, ss58Format);

  console.log(`Address on ${ss58Format}: ${chainAddress}`);
  return chainAddress;
}

Error Handling

Common errors and solutions:

Error Code	Description	Solution
-32603	Internal error	Node may be starting up -- retry after delay
-32005	Rate limit exceeded	Reduce request frequency or implement client-side rate limiting
Connection refused	Node unreachable	Verify the RPC endpoint URL and that the node is running
Empty or alternate result fields	Chain spec missing properties or using `SS58Prefix`	Normalize scalar vs array values and fall back to `SS58Prefix` when `ss58Format` is absent

system_chain -- Get the chain name
system_name -- Get the node implementation name
system_version -- Get the node implementation version
state_getMetadata -- Get full runtime metadata including pallet definitions
rpc_methods -- List all available RPC methods

system_properties - Moonriver RPC Method

When to Use This Method

Code Examples

Common Use Cases

1. Human-Readable Balance Formatting

2. Dynamic Wallet Configuration

3. SS58 Address Encoding and Validation

Error Handling

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