#gas-fees

What it actually costs a user to transact on each Ethereum layer-2 rollup, live and keyless, powered by the public growthepie dataset. Ethereum's base layer is expensive, so most activity has moved to rollups — Arbitrum, Base, OP Mainnet, zkSync Era, Linea, Scroll, Starknet, Mantle, Mode, Metis, Celo, Taiko, Unichain — but the cost of a transaction varies a lot between them, and that is the number a user choosing a chain, or a developer deciding where to deploy, actually wants. This answers "which L2 is cheapest to use right now", in plain dollars. The chains endpoint is the league table: every tracked rollup ranked from cheapest, each with its median transaction cost (USD and ETH), native-transfer cost, token-swap cost, average cost and throughput (transactions per second and Mgas/s); Ethereum L1 is included as the baseline so you can see the L2 saving. The chain endpoint returns one rollup's full current cost-and-performance detail plus a short recent history of its median cost. The cheapest endpoint cuts to the chase — the single cheapest rollup right now for a simple transfer and for a token swap, and how much cheaper that is than Ethereum L1. Because the upstream rounds USD to four decimals (so ultra-cheap rollups would read $0.00), the dollar figures are recovered precisely from each chain's exact ETH cost and the ETH price implied by the same payload — no second data source. This is the L2 user-transaction-cost cut — distinct from the L2 economic-activity feed (active addresses, transaction count, rollup revenue and profit: what the chains earn, not what they cost you), from the multi-chain gas-oracle (gas tiers in gwei) and from the blob data-availability fee market (the L1 cost rollups pay to post data). Costs in USD and ETH, throughput in TPS and Mgas/s, no key, nothing stored.

api.oanor.com/l2fees-api

Live multi-chain EVM gas-fee oracle — the gas estimate every wallet, bridge and dApp needs — computed straight from each network's public JSON-RPC node. Using EIP-1559 fee history it derives the next block's base fee and slow, standard and fast priority-fee tiers from the recent reward percentiles, and returns per tier the priority fee, the suggested max fee and the resulting total gas price, all in gwei. It also estimates the cost of a transaction — a plain transfer or any gas limit you pass — in the chain's native coin. Supports Ethereum, Polygon, BSC, Arbitrum, Optimism, Base and Avalanche. Live, no key, no cache. Distinct from price, market-cap and on-chain TVL APIs — this is the real-time gas-price layer.

api.oanor.com/gasfees-api