54. Immutable X deep-dive — Part 3: Gas and fees
In Part 2 you learned how Immutable X sits as a layer 2 on top of the Ethereum blockchain. In this part, we’ll dive deeper into how Immutable X enables Illuvium to offer gas-free transactions
If Immutable X is on Ethereum, why isn’t there gas?
Here’s the simple answer: Immutable X covers the gas for you! Behind the scenes, Immutable X batches up transactions and is able to pay a cheaper rate to Ethereum for a bulk of transactions.
Immutable X batches thousands of transactions for execution off the main Ethereum chain, and publishes a rolled up, zero-knowledge, validity proof of the transactions to the blockchain. A single hashed proof validates every single transaction in the batch! More detail on zero-knowledge proofs is here, but what you need to know is that the massive reduction in data being written to the blockchain allows Immutable X to cover the gas for the entire protocol and to offer gas-free transactions to users
Does anything cost gas?
Transactions that interact directly with L1 Ethereum cost gas because they can’t be rolled up in Immutable X. For Illuvium users, this means that depositing NFTs or cryptocurrency into Immutable from Ethereum, or withdrawing NFTs to L1 will cost gas.
Isn’t there a fee paid to Immutable X? Isn’t that gas?
Illuvium takes 5% fees on market sales to feed the ILV stakers reward pool. Immutable X takes a 2% fee on market sales — payable by buyers — to keep the lights on for the protocol. It is important to note that these fees aren’t gas — they’re only payable on sales and not transfers which are totally free!