> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sei.io/llms.txt
> Use this file to discover all available pages before exploring further.
# Transactions
> Comprehensive guide on Transactions on Sei. Learn key concepts, commands, and best practices.
Sei supports EVM transactions, allowing compatibility with Ethereum-based tools and contracts. Transactions are signed messages originating from an externally owned account (EOA) that trigger state changes on the blockchain.
## Transaction Lifecycle
| Stage | Description |
| --------------- | ------------------------------------------------------------------------------------------------------ |
| 1. Creation | A transaction is created by an EOA, specifying the recipient, value, gas parameters, and other fields. |
| 2. Signing | The transaction is signed with the sender's private key to create a valid signature. |
| 3. Submission | The signed transaction is submitted to the network through an RPC endpoint. |
| 4. Mempool | The transaction enters the mempool (transaction pool) where it awaits inclusion in a block. |
| 5. Execution | When selected by a validator, the transaction is executed in the EVM, causing state changes. |
| 6. Validation | The transaction and its state changes are validated by the consensus mechanism. |
| 7. Confirmation | Once validated, the transaction is included in a block and confirmed on-chain. |
| 8. Finality | On Sei, transactions achieve immediate finality once included in a block. |
Unlike other EVM chains where you need to wait for multiple confirmations, Sei's consensus mechanism provides immediate transaction finality. Once a transaction is included in a block, it cannot be reversed.
## Gas Mechanics
Gas is a unit of computational work in the EVM that helps prevent spam and allocate resources efficiently:
| Term | Description |
| ------------------- | ------------------------------------------------------------------------------------------------------------------------- |
| Gas Limit | The maximum amount of gas the transaction may consume, set by the sender. |
| Base Fee | The minimum gas price required to be included in a block. On Sei, the base fee is not burned — all fees go to validators. |
| Priority Fee | An additional fee (tip) paid to validators for faster inclusion. |
| Gas Price | In legacy transactions, the price per unit of gas the sender is willing to pay. |
| Effective Gas Price | The actual price paid per unit of gas (base fee + priority fee in EIP-1559). |
**Gas Requirements for Common Operations:**
* Simple SEI transfer: 21,000 gas
* ERC-20 transfer: \~45,000 gas
* Contract deployment: Varies based on contract size and complexity
* Always estimate gas before sending transactions using `eth_estimateGas`
## Transaction Structure
EVM transactions in Sei follow the Ethereum transaction format with standard properties:
| Property | Description |
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `from` | The address of the sender who will sign the transaction. This must be an externally-owned account (EOA) as contract accounts cannot send transactions. |
| `to` | The receiving address. If this is an EOA, the transaction transfers value. If a contract address, the transaction executes the contract code. If empty or null, the transaction creates a new contract. |
| `signature` | The cryptographic signature generated when the sender's private key signs the transaction. This confirms the sender has authorized the transaction and includes the v, r, and s components. |
| `nonce` | A sequentially incrementing counter that indicates the transaction number from the account. This prevents replay attacks and ensures transaction ordering. |
| `data` | The input data (also called 'input' or 'calldata') for contract execution. For simple transfers, this is usually empty. For contract interactions, this contains the function selector and encoded arguments. |
| `value` | Amount of SEI to transfer from sender to recipient (denominated in WEI, where 1 SEI equals 1e+18 WEI). |
| `gasLimit` | The maximum amount of gas units that can be consumed by the transaction. Often referred to as 'gas' in transaction objects. |
| `maxPriorityFeePerGas` | The maximum price of the consumed gas to be included as a tip to the validator (denominated in WEI). Used in EIP-1559 transactions. |
| `maxFeePerGas` | The maximum fee per unit of gas willing to be paid for the transaction (inclusive of baseFeePerGas and maxPriorityFeePerGas). Used in EIP-1559 transactions. |
| `gasPrice` | The price per unit of gas the sender is willing to pay (denominated in WEI). Used in legacy transactions. |
| `chainId` | The chain identifier number. Prevents transaction reuse across different chains. |
| `accessList` | A list of addresses and storage keys that the transaction plans to access. Used in EIP-2930 and EIP-1559 transactions to reduce gas costs for accessing specified addresses and storage slots. |
| `type` | The transaction type: 0 for legacy (pre-EIP-2718), 1 for EIP-2930 access list transactions, and 2 for EIP-1559 fee market transactions. |
| `hash` | The transaction hash, a unique identifier for the transaction generated after signing. |
### Legacy Transactions (Type 0)
Pre-EIP-1559 transaction format that specifies a single gasPrice.
```json theme={"dark"}
{
"from": "0x1923f626bb8dc025849e00f99c25fe2b2f7fb0db",
"to": "0x07a565b7ed7d7a678680a4c162885bedbb695fe0",
"gas": "0x55555",
"gasPrice": "0x1234",
"value": "0x1234",
"data": "0xabcd",
"nonce": "0x0"
}
```
### Access List Transactions (Type 1, EIP-2930)
Transactions with an optional access list of addresses and storage keys to reduce gas costs.
```json theme={"dark"}
{
"type": "0x1",
"from": "0x1923f626bb8dc025849e00f99c25fe2b2f7fb0db",
"to": "0x07a565b7ed7d7a678680a4c162885bedbb695fe0",
"gas": "0x55555",
"gasPrice": "0x1234",
"value": "0x1234",
"data": "0xabcd",
"nonce": "0x0",
"accessList": [
{
"address": "0x07a565b7ed7d7a678680a4c162885bedbb695fe0",
"storageKeys": [
"0x0000000000000000000000000000000000000000000000000000000000000000"
]
}
]
}
```
### Fee Market Transactions (Type 2, EIP-1559)
Transaction format that supports dynamic base fees with a priority fee tip to validators.
```json theme={"dark"}
{
"type": "0x2",
"from": "0x1923f626bb8dc025849e00f99c25fe2b2f7fb0db",
"to": "0x07a565b7ed7d7a678680a4c162885bedbb695fe0",
"gas": "0x55555",
"maxFeePerGas": "0x1234",
"maxPriorityFeePerGas": "0x1234",
"value": "0x1234",
"data": "0xabcd",
"nonce": "0x0",
"accessList": []
}
```
### Example Request: Sending an EIP-1559 Transaction
```json theme={"dark"}
{
"jsonrpc": "2.0",
"method": "eth_sendTransaction",
"params": [
{
"from": "0x1923f626bb8dc025849e00f99c25fe2b2f7fb0db",
"to": "0x07a565b7ed7d7a678680a4c162885bedbb695fe0",
"gas": "0x55555",
"maxFeePerGas": "0x1234",
"maxPriorityFeePerGas": "0x1234",
"value": "0x1234",
"data": "0xabcd",
"nonce": "0x0"
}
],
"id": 2
}
```
### JavaScript example with web3.js
Public RPC endpoints such as `https://evm-rpc.sei-apis.com` do not manage or unlock accounts, so `eth_getAccounts` and `eth_sendTransaction` are not available. Sign transactions locally with a private key and broadcast the raw transaction instead.
```javascript theme={"dark"}
// Example using web3.js v4 to sign and broadcast a transaction.
// Public RPC endpoints do not manage accounts, so sign locally with a private key.
const { Web3 } = require('web3');
const web3 = new Web3('https://evm-rpc.sei-apis.com');
// Load your account from a private key. Never hard-code keys — read from an env var.
const account = web3.eth.accounts.privateKeyToAccount(process.env.PRIVATE_KEY);
async function sendTransaction() {
// Current nonce for the sender
const nonce = await web3.eth.getTransactionCount(account.address);
// Use the latest base fee to set EIP-1559 fees
const block = await web3.eth.getBlock('latest');
const maxPriorityFeePerGas = web3.utils.toWei('1', 'gwei');
const maxFeePerGas = (BigInt(block.baseFeePerGas) + BigInt(maxPriorityFeePerGas)).toString();
const tx = {
from: account.address,
to: '0x07a565b7ed7d7a678680a4c162885bedbb695fe0',
value: web3.utils.toWei('0.1', 'ether'),
gas: 21000, // Gas limit for a simple transfer
maxFeePerGas,
maxPriorityFeePerGas,
nonce,
chainId: 1329 // pacific-1 mainnet (use 1328 for atlantic-2 testnet)
};
// Sign locally, then broadcast the raw transaction
const signed = await web3.eth.accounts.signTransaction(tx, process.env.PRIVATE_KEY);
const receipt = await web3.eth.sendSignedTransaction(signed.rawTransaction);
console.log('Transaction receipt:', receipt);
}
sendTransaction().catch(console.error);
```
### `eth_sendTransaction`
```json theme={"dark"}
{
"jsonrpc": "2.0",
"id": 2,
"result": "0xeba2df809e7a612a0a0d444ccfa5c839624bdc00dd29e3340d46df3870f8a30e"
}
```
### `eth_getTransactionByHash`
```json theme={"dark"}
{
"jsonrpc": "2.0",
"id": 3,
"result": {
"blockHash": "0x5d15649e25d8e7c60b5a1cb3612b6b45dceaa3c774f438d4d5b4e1e1b2db634a",
"blockNumber": "0x92a",
"from": "0x1923f626bb8dc025849e00f99c25fe2b2f7fb0db",
"gas": "0x55555",
"gasPrice": "0x1234",
"hash": "0xeba2df809e7a612a0a0d444ccfa5c839624bdc00dd29e3340d46df3870f8a30e",
"input": "0xabcd",
"nonce": "0x0",
"to": "0x07a565b7ed7d7a678680a4c162885bedbb695fe0",
"transactionIndex": "0x1",
"value": "0x1234",
"type": "0x2",
"accessList": [],
"chainId": "0x1",
"maxFeePerGas": "0x1234",
"maxPriorityFeePerGas": "0x1234",
"v": "0x0",
"r": "0x223a7c9bcf5531c99be5ea7082183816eb20cfe0bbc322e97cc5c7f71ab8b20e",
"s": "0x2aadee6b34b45bb15bc42d9c09de4a6754e7000908da72d48cc7704971491663"
}
}
```
### Transaction receipt
```json theme={"dark"}
{
"jsonrpc": "2.0",
"id": 4,
"result": {
"transactionHash": "0xeba2df809e7a612a0a0d444ccfa5c839624bdc00dd29e3340d46df3870f8a30e",
"transactionIndex": "0x1",
"blockHash": "0x5d15649e25d8e7c60b5a1cb3612b6b45dceaa3c774f438d4d5b4e1e1b2db634a",
"blockNumber": "0x92a",
"from": "0x1923f626bb8dc025849e00f99c25fe2b2f7fb0db",
"to": "0x07a565b7ed7d7a678680a4c162885bedbb695fe0",
"cumulativeGasUsed": "0xd190",
"gasUsed": "0x5208",
"contractAddress": null,
"logs": [],
"status": "0x1",
"logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
"effectiveGasPrice": "0x1234",
"type": "0x2"
}
}
```
## Transaction Guidelines
**Transaction Best Practices:**
* **Set appropriate gas parameters:** Use network conditions to estimate optimal values for `maxFeePerGas` and `maxPriorityFeePerGas`.
* **Manage nonces carefully:** Track and increment nonces correctly to avoid transaction failures.
* **Use typed transactions:** Prefer EIP-1559 transactions (type 2) for more predictable fees.
* **Implement proper error handling:** Account for potential transaction failures and revert reasons.
* **Verify recipient addresses:** Always double-check destination addresses, as transactions cannot be reversed.
| Common Issue | Cause | Solution |
| ------------------------- | -------------------------------------- | -------------------------------------------------- |
| Transaction Underpriced | Gas price or priority fee too low | Increase `maxFeePerGas` and `maxPriorityFeePerGas` |
| Nonce Too Low | Using a nonce that's already been used | Query current nonce with `getTransactionCount` |
| Out of Gas | Gas limit too low for the operation | Use `eth_estimateGas` to set appropriate limit |
| Contract Execution Failed | Contract function reverted | Test with `eth_call` before sending transaction |
## Additional Resources
Complete documentation of Sei's EVM RPC endpoints for transaction creation and monitoring
Learn more about gas calculation, fee estimation, and cost optimization on Sei
Understanding Externally Owned Accounts and Contract Accounts on Sei