Account Abstraction for Agents

Question 1

What is EIP-7702 and how does it change smart accounts?

Accepted Answer

EIP-7702 lets an ordinary Ethereum account (an EOA) delegate to smart contract code, so the same address can batch calls, use sponsored gas or follow spending rules without moving funds to a new smart account. The delegation is set by a signed authorization and lasts until the owner changes or clears it.

Question 2

What is chain abstraction?

Accepted Answer

Chain abstraction means users and agents act without managing which blockchain they are on: they state an outcome, such as paying an amount, and infrastructure chooses the chains, bridges and gas. The Ethereum Foundation's interoperability work aims to make cross-L2 transactions feel like single-chain ones, using intents that solvers execute.

Question 3

What is account abstraction?

Accepted Answer

Account abstraction lets a smart contract act as a user's account, so the account's own code decides how transactions are authorized and paid for. That enables custom security rules, recovery, batching and gas paid by someone else or in other tokens. On Ethereum it is delivered through ERC-4337 and EIP-7702.

Question 4

Why do AI agents need account abstraction?

Accepted Answer

Because the rules can live in the account. A smart account can give an agent a session key with limited permissions, cap its spending, restrict destinations, batch actions and have its gas sponsored, all enforced onchain even if the agent misbehaves. A plain externally owned account gives whoever holds the key full control.

Question 5

What is a bundler in ERC-4337?

Accepted Answer

A bundler is a node that collects UserOperations and submits them to the EntryPoint contract in one transaction, paying the gas up front. Our post explains how bundlers work.

Question 6

How do you estimate gas for a UserOperation?

Accepted Answer

Call a bundler's eth_estimateUserOperationGas method, defined in the ERC-4337 JSON-RPC API. It returns the pre-verification gas, the verification gas limit, the call gas limit and, when a paymaster is used, the paymaster verification gas limit. Add a safety margin, because the paymaster's post-operation gas cannot be estimated reliably.

Question 7

What is a paymaster and how do you sponsor gas for users?

Accepted Answer

A paymaster is an ERC-4337 contract that agrees to pay a UserOperation's gas instead of the sender, so apps can sponsor fees or accept ERC-20 tokens. Our post covers paymasters in production.

Question 8

Can an AI agent pay gas in stablecoins?

Accepted Answer

Yes, through a paymaster. ERC-4337 lets a paymaster accept ERC-20 tokens for gas, so an agent can hold only a stablecoin while the paymaster pays the network fee in the native token and charges the agent in the stablecoin. The paymaster may pre-charge the maximum cost and refund the difference afterwards.

Question 9

What is a relayer in crypto?

Accepted Answer

A relayer is a service that submits transactions to a blockchain on someone else's behalf and pays the gas. The user signs a request offchain, and the relayer broadcasts it. ERC-2771 standardizes this pattern as meta transactions, so contracts can accept calls from accounts that hold no ETH to pay for gas.

Question 10

Relayer vs paymaster: what is the difference?

Accepted Answer

A relayer is an offchain service that sends transactions for users and pays the gas. A paymaster is an onchain ERC-4337 contract that agrees to pay for a UserOperation, which a bundler then submits. Relayers work with meta transactions; paymasters are part of account abstraction and can also accept ERC-20 tokens for fees.

Question 11

EIP-7702 vs ERC-4337: which should you use for agents?

Accepted Answer

They work together. ERC-4337 provides the infrastructure, with UserOperations, bundlers and paymasters, and suits a new smart account created for an agent. EIP-7702 lets an existing address delegate to smart account code while keeping its history and funds. An agent with no prior address can start with ERC-4337 alone.

Question 12

What are session keys and how do they limit what an agent can do?

Accepted Answer

A session key is a separate key that a smart account accepts with limited permissions, such as a spending allowance, allowed contracts and an expiry. An agent signs with the session key instead of the owner's key, so it can only act within those limits. ERC-7715 standardizes how apps request such permissions from wallets.

Question 13

How does chain abstraction affect gas fees?

Accepted Answer

Users stop paying gas chain by chain. With intents, the user states the outcome and a solver executes it across the chains involved, handling the gas and charging for it in the user's chosen token. The total still includes the solver's fee and any bridging, so the experience is simpler, though not necessarily cheaper.

Question 14

How does gas abstraction work with chain abstraction?

Accepted Answer

Gas abstraction lets someone else pay network fees, or accept them in another token, as ERC-4337 paymasters do. Chain abstraction extends that across chains: a solver or paymaster covers the fees on each chain involved, so the user pays once, in one token, without holding the native token of every chain.

Question 15

How does account abstraction work?

Accepted Answer

The account is a smart contract. Under ERC-4337, the user signs a UserOperation describing what to do, a bundler collects it and submits it to the EntryPoint contract, and the EntryPoint calls the account's validation function to check the signature and payment. If validation passes, the account executes the operation, with gas paid by the account or a paymaster.

Question 16

What is ERC-4337?

Accepted Answer

ERC-4337 is the Ethereum standard for account abstraction without changes to the core protocol. Users submit UserOperations to a separate mempool, bundlers package them, and a singleton EntryPoint contract validates and executes them through each smart account. Paymasters can sponsor gas or accept ERC-20 tokens. Its status is Final.

Question 17

How does intent-based architecture relate to chain abstraction?

Accepted Answer

Intents are what make chain abstraction workable. An intent is a high-level statement of what a user wants rather than the exact transactions, and solvers compete to fulfil it across whichever chains are needed. ERC-7683 standardizes the interface between intent protocols and solvers, and the Open Intents Framework provides modular infrastructure for it.

Question 18

What infrastructure is needed for chain abstraction?

Accepted Answer

Smart accounts that can authorize actions on many chains, solvers that fulfil intents, settlement and messaging systems that verify fills across chains, liquidity that can be rebalanced, and gas sponsorship on each chain. The Ethereum Foundation's Open Intents Framework provides modular parts for origination, fulfilment, settlement and rebalancing.

Question 19

How do account abstraction wallets work?

Accepted Answer

An account abstraction wallet is a smart contract that holds the funds, with signing keys as its configurable owners. Its code decides what counts as a valid transaction, so it can require several signers, accept passkeys, allow limited session keys, batch calls and use a paymaster for gas. Operations reach it through ERC-4337 bundlers.

Question 20

Which smart account should you use: Safe, Kernel, Coinbase, or Light?

Accepted Answer

It depends on the job. Safe is a multisig with modules and guards, suited to shared treasury control. Kernel is a modular account built on ERC-7579 with pluggable validators. Coinbase Smart Wallet supports passkey owners and cross-chain owner changes. Light Account is a lightweight ERC-4337 account with single-owner and multi-owner variants.

Question 21

What is a UserOperation receipt and how do you check it?

Accepted Answer

It is the record of how a UserOperation executed: whether it succeeded, the actual gas cost paid by the account or paymaster, and the logs it produced. Fetch it from a bundler with eth_getUserOperationReceipt and the operation's hash. It returns null until the operation has been included in a block.

Question 22

How do gasless transactions work?

Accepted Answer

The user signs without holding gas, and a paymaster or relayer pays the network fee, sponsored by the app or charged in another token. Our post covers how paymasters make this work.

Question 23

Can one smart account work across multiple EVM chains?

Accepted Answer

Yes. A smart account can be deployed at the same address on each EVM chain, and some, such as Coinbase Smart Wallet, let one signed operation be replayed across chains so owner changes stay in sync everywhere. Each chain still keeps its own balance and state, so funds do not move between chains by themselves.

Question 24

What are smart account permissions (ERC-7715) for agents?

Accepted Answer

ERC-7715, a draft standard, defines a wallet method, wallet_requestExecutionPermissions, that lets an app ask a wallet to grant limited execution permissions, such as a native or ERC-20 token allowance with an expiry. For agents, it is a standard way to receive a bounded allowance instead of full control of the account.

Question 25

How secure are dapps with account abstraction?

Accepted Answer

Account abstraction can make apps safer for users, through multisig rules, recovery, spending limits and session keys, but it adds code that must itself be secure. A bug in the account, a module or a paymaster can be exploited, so use audited implementations and limit what modules and session keys are allowed to do.

Question 26

What is an EntryPoint contract?

Accepted Answer

The EntryPoint is the singleton ERC-4337 contract that executes bundles of UserOperations. A bundler calls it with a batch, and it validates each operation by calling the account's validation function and any paymaster, then executes the operations and settles the gas. Each ERC-4337 account works with the EntryPoint version it was built for.

Question 27

What is a UserOperation?

Accepted Answer

A UserOperation is the pseudo-transaction object at the center of ERC-4337: a structure describing what a smart account should do, signed by its owner or an authorized key. It carries the sender, nonce, call data, gas limits and optional paymaster data, and goes to a separate mempool for bundlers instead of being broadcast as a normal transaction.

Question 28

Verifying paymaster vs ERC-20 paymaster: what is the difference?

Accepted Answer

A verifying paymaster sponsors gas for operations that carry its offchain service's signature, so the app decides case by case whom to sponsor. An ERC-20 paymaster pays the gas in the native token and charges the user in an ERC-20 token instead, often pre-charging the maximum cost and refunding the difference.

Question 29

How do you stop a paymaster from being drained?

Accepted Answer

Sponsor only operations you have approved, for example by requiring your service's signature, and cap sponsorship per user and per period. ERC-7562's validation rules and staking requirements protect bundlers from abuse, but your own spending limits and monitoring are what protect the paymaster's deposit from being drained.

Question 30

What is ERC-7579 and what are modular smart accounts?

Accepted Answer

ERC-7579 is a draft standard that defines the minimum interfaces for modular smart accounts, so accounts and modules from different teams work together. It defines four module types: validators, which approve operations; executors, which act for the account; fallback handlers, which extend it; and hooks, which run checks before and after execution.

Question 31

What are smart account modules and plugins?

Accepted Answer

Modules are add-on contracts that give a smart account new abilities without redeploying it: new ways to validate signatures, such as passkeys or session keys, automated actions, extra functions, and checks before or after execution, such as spending limits. Under ERC-7579 they are validators, executors, fallback handlers and hooks.

Question 32

How much does gas sponsorship cost?

Accepted Answer

The sponsor pays the gas the operation actually uses, at the network's price at that moment, plus any fee its paymaster provider charges. The cost therefore varies with the chain, the complexity of the operation and congestion. The UserOperation receipt reports the actual gas cost of each sponsored operation.

Question 33

How does EIP-7702 work?

Accepted Answer

The account owner signs an authorization naming a smart contract, and a transaction of the new type 0x04 sets the account's code to a short delegation indicator pointing at that contract. From then on, calls to the account run the contract's code in the account's own context, with the same address and balance.

Question 34

Is EIP-7702 safe?

Accepted Answer

The mechanism is sound, but the authorization is powerful: the delegated code has unrestricted access to the account. That makes signing an authorization as sensitive as sharing a key. Delegate only to audited contracts you trust, through wallets that show exactly what you are signing, and be wary of any site that asks for one.

Question 35

What phishing risks does EIP-7702 delegation create?

Accepted Answer

An attacker who gets a victim to sign a single EIP-7702 authorization, or who holds a stolen key, can delegate the account to malicious code and drain it, including assets that arrive later. Researchers who measured real incidents found authorizations concentrated in a few malicious contract families that were reused across thefts.

Question 36

How do you revoke an EIP-7702 delegation?

Accepted Answer

Sign and submit a new authorization that delegates to the zero address. That clears the delegation indicator and returns the account to a plain EOA. If the key itself is compromised, revoking is not enough, because the attacker can simply delegate again, so move the funds to a new account.

Question 37

Which wallets support EIP-7702?

Accepted Answer

Support depends on the wallet and its version. MetaMask's Smart Accounts Kit documents upgrading an EOA to a MetaMask smart account with EIP-7702, and Kernel supports both ERC-4337 and EIP-7702 accounts. Check each wallet's documentation before relying on it, since support is still being added and can differ by network.

Question 38

What is an intent-based transaction in crypto?

Accepted Answer

An intent-based transaction is one where the user signs what they want to achieve, such as swapping a token for at least a set amount, instead of the exact steps. Specialized solvers compete to fulfil it and are paid for doing so. Intents are declarative, while ordinary transactions are prescriptive.

Question 39

What is a solver in intent-based systems?

Accepted Answer

A solver, also called a filler, is a specialized party that executes the actions needed to fulfil a user's intent and is paid for it. Solvers compete on price and speed and take on execution risks such as bridging and gas. ERC-7683 defines a common interface between intent protocols and solvers.