Send Transactions on EVM-Compatible Chains Using OKX Wallet

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Blockchain transactions are the backbone of decentralized interactions, enabling users to transfer assets, interact with smart contracts, and modify on-chain states. In the world of Ethereum Virtual Machine (EVM)-compatible networks, one of the most essential methods for initiating these actions is eth_sendTransaction. This guide dives deep into how developers and users can seamlessly send transactions using OKX Wallet — a secure, user-friendly Web3 extension wallet that supports multiple EVM chains.

Whether you're building a decentralized application (DApp), integrating a decentralized exchange (DEX), or simply managing digital assets, understanding transaction parameters and wallet integration is crucial.

Understanding eth_sendTransaction

The eth_sendTransaction method is used to broadcast a signed transaction to the blockchain. Every action — from sending native tokens to deploying smart contracts — begins with this call. In OKX Wallet, transactions are initiated via the okxwallet.request method, ensuring secure signing without exposing private keys.

All transactions must be signed by an external account (a user-controlled wallet) and include specific data fields that define the transaction’s behavior on-chain.

👉 Discover how to securely initiate blockchain transactions with ease.

Transaction Parameters Explained

When constructing a transaction, several parameters come into play. While many are handled automatically by OKX Wallet, understanding them empowers developers to build more robust and efficient DApps.

Legacy Transactions

Legacy transactions follow the original Ethereum format and remain supported across most EVM-compatible chains.

Gas Price [Optional]

This defines how much you're willing to pay per unit of gas. Higher gas prices typically result in faster confirmation times, as validators prioritize transactions offering better rewards.

While OKX Wallet provides preset options like "slow," "medium," and "fast" for simplicity, advanced users or applications targeting custom networks may manually set this value. However, note that some Layer 2 solutions use fixed or near-zero gas fees, making this parameter irrelevant in those contexts.

Gas Limit [Optional]

The gas limit sets the maximum amount of gas the transaction can consume. If execution exceeds this limit, the transaction fails and fees are still charged.

OKX Wallet automatically estimates a safe gas limit for most operations. Manual adjustment is rarely needed unless dealing with complex smart contract logic requiring precise control over resource usage.

To [Optional]

A hex-encoded Ethereum address specifying the recipient. This field is required for standard transfers and contract calls but omitted during contract creation.

For example:

Value [Optional]

Represents the amount of native currency (e.g., ETH, BNB, MATIC) to send, encoded in hexadecimal format and denominated in the smallest unit (like Wei for Ethereum).

Due to precision limitations in JavaScript, handling large numbers directly can lead to rounding errors. To avoid issues, always use libraries like BN.js when performing arithmetic on blockchain values.

Data [Optional]

Used for two primary purposes:

  1. Smart Contract Deployment – Contains compiled bytecode when creating a new contract.
  2. Function Calls – Encodes function selectors and arguments using the Solidity ABI specification.

This field is essential for interacting with DeFi protocols, NFT marketplaces, or any DApp with on-chain logic.

Chain ID [Currently Ignored]

Although part of the transaction structure, OKX Wallet currently derives the chain ID from the user's selected network (okxwallet.networkVersion). Developers don't need to specify it manually.

Return Value

Upon successful submission, the method returns a 32-byte transaction hash (e.g., 0xabc123...). A zero hash indicates the transaction hasn't been processed yet.

After deploying a contract, use eth_getTransactionReceipt to retrieve the newly created contract address once the transaction is mined.

EIP-1559 Transactions

Modern EVM chains support EIP-1559, which improves fee market efficiency by introducing dynamic base fees and optional priority tips.

Instead of using gasPrice, EIP-1559 transactions utilize:

maxPriorityFeePerGas [Optional]

The extra tip offered to miners or validators for prioritizing your transaction. This influences how quickly your transaction gets included in a block.

maxFeePerGas [Optional]

The total maximum fee per gas unit you're willing to pay, combining both the network’s base fee and your priority tip. The actual fee paid will never exceed this value and often ends up lower if base fees drop.

This model offers greater predictability and reduces overpayment — especially valuable during periods of high network congestion.

👉 Learn how EIP-1559 simplifies transaction fee management across blockchains.

Practical Example: Sending a Transaction

To initiate a transaction through OKX Wallet:

await okxwallet.request({
  method: 'eth_sendTransaction',
  params: [
    {
      from: '0xYourAddress',
      to: '0xRecipientAddress',
      value: '0xDE0B6B3A7640000', // 1 ETH in Wei
      gasLimit: '0x5208', // Optional: 21,000 gas
      maxPriorityFeePerGas: '0x3B9ACA00', // Optional tip
      maxFeePerGas: '0x2540BE400' // Max fee: 10 Gwei
    }
  ]
});

This triggers a secure popup in OKX Wallet where users review and approve the transaction before signing.

For legacy transactions, replace maxPriorityFeePerGas and maxFeePerGas with gasPrice.

Frequently Asked Questions (FAQ)

Q: Can I send tokens using eth_sendTransaction?
A: Yes, but only native tokens (like ETH or BNB). For ERC-20 or other token standards, you must call the token contract's transfer function via the data field.

Q: What happens if I set too low a gas limit?
A: The transaction will fail due to an "out of gas" error. While no state changes occur, the gas used up to that point is still deducted from your balance.

Q: How do I know which transaction type my network supports?
A: Most modern EVM chains (Ethereum, Polygon, BSC) support EIP-1559. Check your network documentation or test with maxFeePerGas. If unsupported, fall back to legacy format.

Q: Is it safe to leave gasPrice undefined?
A: Yes. OKX Wallet automatically selects competitive pricing based on current network conditions unless you're on a niche or private chain.

Q: Why do I need BN.js for value handling?
A: Native JavaScript numbers can't accurately represent very large integers (like 1e18 Wei). BN.js ensures precision during calculations and prevents overflow bugs.

👉 Start building seamless Web3 experiences with reliable wallet integration.

Core Keywords

By mastering these concepts and leveraging OKX Wallet’s intuitive API, developers can create efficient, secure, and user-friendly blockchain applications across multiple networks. Whether you're launching a DeFi platform or integrating NFT functionality, proper transaction handling is foundational to success in Web3.