Building a Web3 Wallet: Step-by-Step Guide

This comprehensive guide walks you through creating a Web3 wallet, managing addresses across multiple chains, constructing transactions, and querying blockchain data using Wallet-as-a-Service (WaaS) APIs.

Step 1: Generate Wallet Mnemonic and Addresses

Begin by creating your wallet's cryptographic foundation using our Signature SDK.

Installation and Setup

For EVM-compatible networks:

npm install @okx/js-wallet-sdk

Local Development

Clone the project repository
Execute build scripts

Here's how to create an EVM wallet object and derive its address:

const { EVMWallet } = require('@okx/js-wallet-sdk');
const wallet = new EVMWallet();
const address = wallet.getAddress();

👉 Explore live demo of this functionality in our interactive playground.

Step 2: Create Your Account Organization

After generating addresses, consolidate them under an AccountId for batch operations.

Web3 Wallet Hierarchy:

Wallet: Controlled by whoever holds the mnemonic phrase
Account: Multiple accounts per mnemonic (BIP-44 standard)
Address: Unique chain-specific addresses per account

Call the Create Wallet Account API to establish your organizational structure.

Step 3: Construct and Broadcast Transactions

Prepare Transaction Metadata

Request essential signing data via POST /api/v5/wallet/pre-transaction/sign-info including:

Gas parameters (price/limit)
Nonce values
Network-specific requirements

Transaction Construction Flow

Validate recipient addresses
Assemble transaction components
Generate cryptographic signatures

👉 Transaction broadcasting service ensures reliable propagation to blockchain networks.

Sample broadcast response:

{
  "txHash": "0x...",
  "status": "pending"
}

Step 4: Monitor Transaction Lifecycle

Track execution details through:

Successful query response:

{
  "blockHeight": 123456,
  "confirmations": 12,
  "fee": "0.0012 ETH"
}

FAQ: Web3 Wallet Development

What's the difference between HD wallets and single-address wallets?

Hierarchical Deterministic (HD) wallets generate unlimited addresses from one seed, while single-address wallets use fixed addresses. HD wallets offer better privacy and management.

How secure are mnemonic phrases?

12-24 word mnemonics provide 128-256 bit security when properly generated. Always store them offline in encrypted form.

Can I support multiple chains with one API?

Yes, WaaS APIs provide unified interfaces for EVM, Solana, Bitcoin, and other major networks through standardized endpoints.

What's the typical transaction confirmation time?

Varies by chain:

Ethereum: 15s - 5min
Solana: 400ms - 2s
Bitcoin: 10-60 minutes

How do gas fees work?

Gas fees compensate validators for computation/storage. Fees fluctuate based on network congestion and transaction complexity.

Can I recover funds if I lose my mnemonic?

No. Mnemonics are the ultimate key custodian. Consider implementing multi-sig or custodial solutions for institutional use cases.

This guide covers fundamental Web3 wallet operations. For advanced features like DeFi integrations, NFT management, or cross-chain swaps, explore our complete API documentation.