What is a paymaster and how to sponsor gas (ERC-4337 and EIP-7702)
Understand what a paymaster is, the difference between ERC-4337 and EIP-7702, and how to sponsor your users gas without them switching wallets.
What is a paymaster
A paymaster is an account-abstraction component that pays the gas on the user's behalf. Instead of the user needing the network's native coin to transact, a sponsor (you, the company) covers that cost. It's what enables the "gasless" experience modern apps offer.
ERC-4337 vs EIP-7702
- ERC-4337 introduces Smart Accounts (accounts that are contracts) and UserOperations, processed by a bundler and an EntryPoint. Powerful, but it requires the user to have a smart account.
- EIP-7702 lets a plain account (EOA) temporarily delegate to a contract. The big win: the user does not need to migrate wallets to get gasless transactions.
VKX uses the EIP-7702 model for its gas service precisely for that reason — your users keep the wallets they already have.
How to sponsor in practice
- You keep a prepaid balance (one deposit serves all EVM chains).
- Your backend requests the sponsorship, the user signs the operation, and it's submitted.
- The paymaster validates and pays; you are charged for the transaction's real gas.
With VKX Gas, that's an API call (npm package @vkx/gas), with cashback that subsidizes future transactions. Details and pricing at https://vkxtech.com.br/gas.
When to use it
Whenever "you need gas" is why your user gives up: NFT mints, games, fintech, loyalty, on-ramp. Sponsoring gas turns a technical obstacle into an ordinary app experience.
Learn more: https://vkxtech.com.br/gas