Gas and fees

Arc denominates all transaction fees in USDC, the native gas token. The fee market uses an EIP-1559 pricing model combined with exponentially weighted moving average (EWMA) smoothing — a technique that calculates the base fee from a weighted running average of recent block utilization, giving more weight to recent blocks and less to older ones. This produces stable, predictable gas costs. For the mechanism design behind these parameters, see Stable fee design.

Fee parameters

Parameter	Value	Notes
Gas unit	USDC (18 decimals)	Native gas accounting precision
Pricing model	EIP-1559 + EWMA smoothing	Replaces per-block recalculation with a moving average
Base fee target	~$0.001 per ERC-20 transfer	Design-time target under normal load
Minimum base fee	20 Gwei	Floor enforced by the protocol
Maximum base fee	20,000 Gwei	Hard ceiling that bounds worst-case cost
Gas throughput	30M gas/block (~60M gas/sec at 0.5 s block time)	Protocol-level capacity limit
Smoothing method	EWMA of block utilization	Short spikes do not propagate into sudden fee jumps

The EWMA smoothing window calculates each new base fee as a weighted blend of the previous base fee and the latest block’s gas utilization ratio. Because older blocks carry exponentially decreasing weight, short traffic spikes raise the fee only slightly, and the base fee returns to its target quickly once utilization normalizes.

The 18-decimal precision in the preceding table applies to Arc’s native gas accounting. USDC on Arc also provides a standard ERC-20 interface with 6 decimals for application-level transfers. These are not two separate tokens — they share the same underlying balance. See Contract addresses for the ERC-20 address.

Submitting transactions

Follow these practices to ensure timely transaction inclusion on Arc.

Set an adequate max fee

Set maxFeePerGas to at least 20 Gwei. Transactions submitted under this floor may remain pending indefinitely or fail outright.

import { ethers } from "ethers";

const provider = new ethers.JsonRpcProvider("https://rpc.mainnet.arc.io");
const wallet = new ethers.Wallet(process.env.PRIVATE_KEY, provider);

const tx = await wallet.sendTransaction({
  to: recipient,
  value: ethers.parseUnits("1", 6), // 1 USDC via native send
  maxFeePerGas: ethers.parseUnits("20", "gwei"),
});

Set maxPriorityFeePerGas (the EIP-1559 tip) to incentivize sequencer inclusion. A value of 0 Gwei is accepted, but a small tip (for example, 1 Gwei) can improve inclusion time during high-utilization periods.

Fetch the current base fee

Query the Arc RPC before submitting to get the latest fee data. Two standard methods are available:

Method	Returns	Use case
`eth_gasPrice`	Suggested gas price as a single value	Quick estimation for simple transactions
`eth_feeHistory`	Base fee and priority fee history over recent blocks	Fine-grained estimation when you need historical context

import { ethers } from "ethers";

const provider = new ethers.JsonRpcProvider("https://rpc.mainnet.arc.io");

// Fetch current gas price
// Returns: hex string (e.g., "0x4a817c800" = 20 Gwei)
const gasPrice: string = await provider.send("eth_gasPrice", []);

// Fetch fee history for the last 5 blocks
// Returns: { baseFeePerGas: string[], gasUsedRatio: number[], reward: string[][] }
const feeHistory = await provider.send("eth_feeHistory", [
  "0x5", // block count
  "latest", // newest block
  [25, 50, 75], // percentiles
]);

Arc publishes the next block’s base fee in the parent header’s extra_data field as an 8-byte big-endian value, so you can read it directly from the block header.

Display fees in USDC

Because Arc denominates gas in USDC, surface fee estimates to users in dollar terms rather than raw Gwei. This avoids confusion and aligns with the stablecoin-native model.

Common errors

Error	Cause	Resolution
`transaction underpriced`	`maxFeePerGas` is lower than the 20 Gwei minimum base fee floor	Increase `maxFeePerGas` to at least `ethers.parseUnits("20", "gwei")` and resubmit
`intrinsic gas too low`	Gas limit is lower than the intrinsic cost of the transaction	Set the gas limit to at least 21,000 for simple transfers; use `eth_estimateGas` for contract calls
`insufficient funds for gas * price + value`	The sending account’s USDC balance cannot cover both the transfer value and the gas fee	Fund the account with enough USDC to cover the total cost (value + maxFeePerGas x gasLimit)

Monitoring

View real-time gas metrics and recent averages using the Arc Gas Tracker. The tracker displays current base fee, historical trends, and per-block utilization. For testnet, use the Arc Testnet Gas Tracker.

Key Features

Network

Fee parameters

Submitting transactions

Set an adequate max fee

Fetch the current base fee

Display fees in USDC

Common errors

Monitoring

​Fee parameters

​Submitting transactions

​Set an adequate max fee

​Fetch the current base fee

​Display fees in USDC

​Common errors

​Monitoring

Fee parameters

Submitting transactions

Set an adequate max fee

Fetch the current base fee

Display fees in USDC

Common errors

Monitoring