Gas and Fees

Sei gas price floor, EIP-1559 fee model differences, and SSTORE cost

Gas and Fees

Sei supports both legacy and EIP-1559 transactions, but the fee model differs from Ethereum in three ways that affect how you estimate and set gas.

Legacy Gas Price Floor

Legacy transactions (type 0) on Sei must meet a minimum gas price set by on-chain governance. This floor can change via governance proposals — do not hard-code a specific value.

Use eth_gasPrice to read the current minimum:

viem

import { createPublicClient, http } from 'viem';
import { sei } from '@sei-js/precompiles/viem';

const client = createPublicClient({ chain: sei, transport: http() });
const gasPrice = await client.getGasPrice();

EIP-1559 Fee Model

Sei supports EIP-1559 transactions (type 2), but does not burn the base fee. Fees go entirely to validators rather than being partially burned as on Ethereum.

This does not affect how you construct or send transactions — maxFeePerGas and maxPriorityFeePerGas work as expected. It is relevant only if your application models token supply or displays fee-burn information to users.

viem

const fees = await client.estimateFeesPerGas();
// fees.maxFeePerGas and fees.maxPriorityFeePerGas are usable as-is

SSTORE Cost

The gas cost of SSTORE (writing to contract storage) is governance-adjustable on Sei. Do not hard-code storage write estimates in your application.

Always use eth_estimateGas for any transaction that writes to storage:

viem

const gas = await client.estimateGas({
  account,
  to: contractAddress,
  data: encodedCalldata,
});

// Add a buffer for governance changes during high-activity periods
const gasWithBuffer = (gas * 120n) / 100n; // 20% buffer

Summary

Behavior	Ethereum	Sei
Legacy gas floor	Protocol minimum	Governance-set, can change
Base fee	Burned	Paid to validators
SSTORE cost	Fixed by EIP	Governance-adjustable
estimateGas	Always correct to use	Required — do not hard-code storage costs