An ERC-4337 paymaster is an optional smart contract that can agree to cover the gas cost of a smart account’s UserOperation under defined rules. It can make an app feel “gasless” to a user, but the network still charges for execution: the account, sponsor or paymaster-funded deposit covers that cost.
How sponsorship works
A paymaster validates the operation and supplies the required paymaster data. EntryPoint then accounts for the gas charge and pays the bundler from the relevant account or paymaster deposit. Sponsorship can be conditional, limited to selected actions or users, or capped by a budget. The app or sponsor is paying under its policy; the fee has not disappeared.
Contract versus web service
The paymaster contract is the on-chain component that participates in validation and payment. ERC-7677 separately describes a web-service capability that apps and wallets can use to request paymaster data. A service can quote or sign sponsorship data, but the contract’s on-chain checks determine whether the operation is accepted. ERC-4337 does not make native gas fees automatically payable in any ERC-20 token; token-based charging needs an explicit design and conversion or settlement logic.
Risks and limits
A sponsor must fund the deposit and protect its policy from abuse. Weak validation or replay controls can expose the sponsor to losses or make its operations unattractive to bundlers; restrictive policies can reject legitimate users. Users also depend on the sponsor’s availability and rules. “Gasless” therefore describes who covers a displayed fee, not a free or risk-free transaction.
Social Media Sentiment
A July 2025 Ethereum Magicians exchange discussed a proposed ZK-based paymaster and a possible replay or spam burden on bundlers. Replies debated rate limits, stake and nullifier checks. This is a focused technical exchange about one design, not evidence that all paymasters have the same vulnerability. the July 2025 paymaster anti-spam discussion
Last updated: 2026-10
Related Terms
See Also
- Why Calling It a Wallet May Have Been Crypto’s Biggest Mistake
- What Is MEV?
- Are Layer 2 Networks Actually Decentralized?
- ChangeNOW
Sources
- ERC-4337 specification — Defines paymaster validation, EntryPoint accounting and the deposit used to cover UserOperation gas.
- ERC-7677 Paymaster Web Service Capability — Defines how an app can ask a wallet to communicate with a paymaster web service.
- ERC-7562 validation scope rules — Documents validation constraints and reputation protections relevant to paymaster and bundler operations.