token-portfolio
DevelopmentBuild wallet portfolio features with ERC-20 token discovery, multicall balances, CoinGecko pricing, and multi-account scanning (.NET/C#). Use this skill when the user asks about token balances, token portfolios, token prices, token lists, multicall token queries, multi-wallet scanning, or CoinGecko integration.
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Token Portfolio & Balances
Nethereum.TokenServices builds a wallet portfolio from an embedded list of thousands of known tokens per chain — checking all of them via batched multicall (balanceOf reads in a single eth_call). No chain indexing, no third-party indexer dependency. Works against any standard RPC endpoint. Optional CoinGecko pricing, multi-account scanning, and a persistent token catalog.
NuGet: Nethereum.TokenServices
dotnet add package Nethereum.TokenServices
Quick Start
using Nethereum.TokenServices.ERC20;
using Nethereum.TokenServices.ERC20.Balances;
using Nethereum.Web3;
var web3 = new Web3("https://eth.llamarpc.com");
var tokenService = new Erc20TokenService();
var balances = await tokenService.GetBalancesWithPricesAsync(
web3, accountAddress, chainId: 1, vsCurrency: "usd",
includeNative: true, NativeTokenConfig.ForChain(1, "ETH", "Ether"));
foreach (var b in balances.Where(x => x.Value > 0).OrderByDescending(x => x.Value))
Console.WriteLine(quot;{b.Token?.Symbol}: {b.BalanceDecimal:N4} @ ${b.Price:N2} = ${b.Value:N2}");
Key Methods
IErc20TokenService
// All balances with prices
var balances = await tokenService.GetBalancesWithPricesAsync(
web3, address, chainId, "usd", includeNative: true, nativeToken);
// Balances only (no prices)
var balances = await tokenService.GetAllBalancesAsync(
web3, address, chainId, includeNative: true, nativeToken);
// Specific tokens only
var balances = await tokenService.GetBalancesForTokensWithPricesAsync(
web3, address, tokenList, "usd");
// Incremental refresh via Transfer events (returns List<TokenBalance>)
var updated = await tokenService.RefreshBalancesFromEventsAsync(
web3, address, chainId, fromBlock, existingTokens, "usd");
// Token lookup
var tokens = await tokenService.GetTokenListAsync(chainId);
var token = await tokenService.GetTokenAsync(chainId, contractAddress);
// Pricing
var prices = await tokenService.GetPricesForTokensAsync(chainId, contractAddresses, "usd");
var ethPrice = await tokenService.GetNativeTokenPriceAsync(chainId, "usd");
Models
// TokenBalance — returned by all balance methods
public class TokenBalance
{
public TokenInfo Token { get; set; }
public BigInteger Balance { get; set; }
public bool IsNative { get; set; }
public decimal BalanceDecimal { get; } // Converted from Wei
public decimal? Price { get; set; }
public decimal? Value { get; } // BalanceDecimal * Price
}
// TokenInfo — token metadata
public class TokenInfo
{
public string Address { get; set; }
public string Symbol { get; set; }
public string Name { get; set; }
public int Decimals { get; set; }
public string LogoUri { get; set; }
public long ChainId { get; set; }
public string CoinGeckoId { get; set; }
}
Batch Price Service
using Nethereum.TokenServices.ERC20.Pricing;
var batchPrice = new BatchPriceService(new CoinGeckoPriceProvider());
var request = new BatchPriceRequest("usd")
.AddChain(1, new[] { "0xA0b86991...", "0xdAC17F..." }, includeNative: true)
.AddChain(137, new[] { "0x2791Bca1..." }, includeNative: true);
var result = await batchPrice.GetPricesAsync(request);
if (result.TryGetPrice(1, "0xA0b86991...", out var price))
Console.WriteLine(quot;USDC: ${price.Price}");
if (result.TryGetNativePrice(1, out var ethPrice))
Console.WriteLine(quot;ETH: ${ethPrice.Price}");
Multi-Account Scanning
using Nethereum.TokenServices.MultiAccount;
var multiService = serviceProvider.GetRequiredService<IMultiAccountTokenService>();
var strategy = serviceProvider.GetRequiredService<IDiscoveryStrategy>();
var result = await multiService.ScanAsync(
accounts: new[] { "0xWallet1...", "0xWallet2..." },
chainIds: new[] { 1L, 137L, 42161L },
web3Factory: chainId => new Web3(GetRpcUrl(chainId)),
strategy: strategy,
options: new MultiAccountScanOptions { MaxParallelChains = 3, IncludeNativeToken = true },
progress: new Progress<MultiAccountProgress>(p =>
Console.WriteLine(quot;{p.CompletedChains}/{p.TotalChains} chains, {p.TokensFound} tokens")));
// Results by chain / by account
foreach (var (chainId, chainResult) in result.ChainResults)
Console.WriteLine(quot;Chain {chainId}: {chainResult.TokensFound} tokens");
// Price-only refresh
var priceResult = await multiService.RefreshPricesAsync(accountTokens, "usd");
Token Catalog
Persistent, refreshable token registry:
using Nethereum.TokenServices.Catalog;
// Setup
services.AddTokenCatalog(options =>
{
options.CatalogDirectory = "/data/catalog";
options.AutoSeedFromEmbedded = true;
options.RegisterCoinGeckoSource = true;
});
// Query
var repo = serviceProvider.GetRequiredService<ITokenCatalogRepository>();
var tokens = await repo.GetAllTokensAsync(chainId: 1);
var usdc = await repo.GetTokenByAddressAsync(chainId: 1, "0xA0b86991...");
// Refresh
var refreshService = serviceProvider.GetRequiredService<ITokenCatalogRefreshService>();
var result = await refreshService.RefreshAsync(chainId: 1);
// Use catalog as token list provider
var adapter = new CatalogTokenListProviderAdapter(repo, autoSeed: true);
var tokenService = new Erc20TokenService(tokenListProvider: adapter);
Discovery Strategies
| Strategy | How It Works | Speed |
|---|---|---|
TokenListDiscoveryStrategy (default) | Check known tokens via multicall | Fast |
EventLogDiscoveryStrategy | Scan all Transfer events | Thorough but slow |
Custom IDiscoveryStrategy | Your logic | Varies |
Dependency Injection
// Basic
services.AddErc20TokenServices();
// With options
services.AddErc20TokenServices(options =>
{
options.UseFileCache = true;
options.CacheDirectory = "/data/cache";
options.PriceCacheExpiry = TimeSpan.FromMinutes(5);
options.MultiCallBatchSize = 100;
});
// Custom providers
services.AddErc20TokenServices()
.UseTokenListProvider<MyProvider>()
.UsePriceProvider<MyPriceProvider>()
.UseDiscoveryStrategy<MyStrategy>();
Supported Chains (Built-in)
Ethereum (1), Optimism (10), BNB Chain (56), Gnosis (100), Polygon (137), zkSync Era (324), Base (8453), Arbitrum (42161), Celo (42220), Avalanche (43114), Linea (59144).