Batch Token Balance Retrieval in Mobile Wallet

Batch Balance Retrieval for ERC-20, BEP-20 & SPL Tokens in Mobile Wallet

Imagine: a user opens a wallet and waits for balances to load — one second per token. With 20 tokens, that's 20 seconds. The user closes the app. A classic RPC request per contract gives a 2-3 second delay per token, totaling a minute for a portfolio of 30 assets. We solve this problem through batch loading with Multicall3, caching, and parallel requests for different networks. Our experience shows that proper architecture cuts loading time to 1-2 seconds, regardless of token count. This 20x speedup keeps users engaged and boosts transaction conversion.

Loading Balances in Batch

Multicall3 — contract 0xcA11bde05977b3631167028862bE2a173976CA11 — is deployed in most EVM networks (Ethereum, Polygon, BNB Chain, Arbitrum, Optimism, Base). A single aggregate3 call returns balances of all tokens in one read transaction, leveraging atomicity of on-chain calls and minimizing I/O-bound operations. Comparison of methods:

Multicall3 reduces RPC calls by 20x and is 10-20x faster than sequential requests.

Step-by-Step Multicall3 Integration

1. Initialize the Multicall3 contract in the wallet code. The address is the same for all networks — 0xcA11bde05977b3631167028862bE2a173976CA11.
2. Build an array of Call3 for each token: target, allowFailure: true, callData = balanceOf(address) (ABI encoding of the function).
3. Call aggregate3 — get an array of results with rawBalance and success.
4. Process results: for each token, extract rawBalance, divide by 10^decimals.
5. Display balances in UI in parallel with price loading.

// iOS — web3swift + Multicall3 let multicallAddress = EthereumAddress("0xcA11bde05977b3631167028862bE2a173976CA11")! var calls: [Multicall3.Call3] = [] for tokenAddress in tokenAddresses { let callData = ERC20.balanceOf(owner: walletAddress).encodeABI() calls.append(.init(target: tokenAddress, allowFailure: true, callData: callData)) } let results = try await multicall3.aggregate3(calls: calls) 

// Android — web3j + manual Multicall assembly val multicallEncoder = Function("aggregate3", listOf(DynamicArray(calls)), listOf()) val encodedCall = FunctionEncoder.encode(multicallEncoder) val response = web3j.ethCall(Transaction.createEthCallTransaction(null, multicallAddress, encodedCall), DefaultBlockParameterName.LATEST).send() 

For networks without Multicall3 (some L2s or private EVM chains) — use JSON-RPC batch request: an array of calls in one HTTP body. Most nodes support up to 100 requests per batch.

What About SPL Tokens on Solana?

Solana is fundamentally different: each SPL token is stored on a separate Associated Token Account (ATA). The list of ATAs for a wallet is obtained via getTokenAccountsByOwner with program TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA.

// iOS — SolanaSwift let tokenAccounts = try await solana.action.getTokenAccountsByOwner( pubkey: walletPublicKey, params: .init(programId: TokenProgram.publicKey), configs: nil ) for account in tokenAccounts { let mint = account.account.data.parsed.info.mint let amount = account.account.data.parsed.info.tokenAmount.uiAmount } 

A user can have 50+ ATAs, including zero balances from old airdrops. We hide zero balances by default but provide an option to show all. This keeps the UI clean without losing information.

Why Decimals and Prices Matter?

Displaying balance without a fiat equivalent is only half the job. For prices, we use CoinGecko API (/simple/price?ids=...&vs_currencies=usd) or CoinMarketCap. CoinGecko Free tier offers 30 requests per minute, enough for most wallets. Token keys are contract addresses, not tickers. For Ethereum: https://api.coingecko.com/api/v3/simple/token_price/ethereum?contract_addresses=0x...&vs_currencies=usd. Batch up to 100 contracts per request.

Token decimals are critical: per ERC-20 specification, the contract returns balance in the smallest unit. USDC has 6 decimals, ETH 18. Displayed balance: rawBalance / 10^decimals. An error in decimals makes the balance appear astronomical or zero. We guarantee correct decimals reading from the contract at initialization.

Common mistakes with decimals:

• Contracts that don't implement decimals() return 0 decimals — we use fallback 18.
• Some tokens (e.g., USDT on Tron) have 6 decimals, but EVM versions have 6 or 18.
• When a user manually adds a token, they may enter incorrect decimals — we re-check via on-chain data.

Caching Scheme and Update Frequency

Personal case: For a DeFi project, we integrated balance display across 4 networks (Ethereum, BSC, Polygon, Solana) and 30 tokens. Load time dropped from 12 seconds to 2.5 seconds thanks to batch requests and cursor caching.

Deliverables & What's Included

• Designing balance loading architecture tailored to your target audience.
• Integrating Multicall3 for EVM networks and getTokenAccountsByOwner for Solana.
• Connecting fiat price feeds with caching.
• Developing token list UI with pull-to-refresh, search, and zero balance hiding.
• Testing on 10+ popular tokens in each network.
• Handing over access to App Store Connect / Google Play Console.
• Documentation for operation and one month of post-release support.

Estimated Timeline and Cost

Implementation typically takes 3 to 7 days depending on the number of networks and UI requirements. For a standard solution (EVM + Solana + prices) — 5 days. Estimated cost: $2,000–$5,000, varying with complexity. Contact us for a free project evaluation and precise timeline. Our engineers have 5+ years of mobile development experience and ensure compliance with App Store Review Guidelines and Play Console policies.

Order token balance display implementation for your wallet — get a turnkey solution. Get a consultation right now.