LibraryData and agents2021Design paperCorpus record
Account Abstraction Using Alt Mempool
ERC-4337. Vitalik Buterin, Yoav Weiss, Dror Tirosh, Shahaf Nacson, Alex Forshtat, Kristof Gazso and Tjaden Hess.
Smart-contract accounts that propose UserOperations, bundled by a separate mempool, without a change to Ethereum's consensus. Paymasters can sponsor gas. The validation rule lives in the account, which is the point and the risk.
ERC-4337 lets a smart contract be the account. Users submit UserOperations to a separate mempool. Bundlers wrap them into an ordinary Ethereum transaction. No consensus change is required. The account's own code decides what counts as authorisation.
- Evidence
- Primary paper
- Re-measured
- No
- Assumptions
- 4
- Records linked
- 10
Code
Source, repository, and what is actually hosted
- EIP-4337https://eips.ethereum.org/EIPS/eip-4337
- The source URL is not a GitHub repository. No code remote is invented.
- Full text is not mirrored. Public availability is not a licence to copy the file onto this site.
- Add to a reading list
01 Claim ledger
What the paper is allowed to say
Each row is a sentence already in the study. The status is the same on every row: a model claim, not a live measurement.
Claim 01 · Paper model
Above the protocol, not inside it
Validators still see a normal transaction from the bundler to the EntryPoint. They do not need to understand a UserOperation. That is how the proposal shipped without a fork. It is also why a bundler's mempool is a new place for the usual games.
Claim 02 · Paper model
Validation is programmable
The account defines what a valid signature is. It might be a multisig, a passkey, or a session key for an agent. A bug in that function is a bug in the lock, not in Ethereum's transaction format.
Claim 03 · Paper model
Paymasters sponsor gas
A contract can pay the bundler if its own checks pass and it has deposited funds. Sponsorship can be revoked, emptied, or used as a censor. It is not a protocol right.
Claim 04 · Paper model
Simulation has rules
Bundlers simulate validation before including an operation. The specification restricts what validation may read, so a sender cannot make the simulation succeed and the execution fail in a way that wastes the bundler. Those restrictions are the spec. Ignoring them makes the mempool griefable.
02 Three cuts
Observation, model, falsifier
A desk does not stop at the summary. Each claim is cut three ways, using only this study's own assumptions and checks. Nothing here is a new figure.
01 Above the protocol, not inside it
Observation
What the study says
Validators still see a normal transaction from the bundler to the EntryPoint. They do not need to understand a UserOperation. That is how the proposal shipped without a fork. It is also why a bundler's mempool is a new place for the usual games.
Model
What has to hold
Bundlers exist and find the operation. There is no protocol guarantee that the alt mempool is dense.
Falsifier
What would retire it
Which EntryPoint does the account trust?
02 Validation is programmable
Observation
What the study says
The account defines what a valid signature is. It might be a multisig, a passkey, or a session key for an agent. A bug in that function is a bug in the lock, not in Ethereum's transaction format.
Model
What has to hold
The EntryPoint used by the account is the contract the holder meant. A fake entry point can pass a wallet's user interface and fail the user.
Falsifier
What would retire it
Which EntryPoint does the account trust?
03 Paymasters sponsor gas
Observation
What the study says
A contract can pay the bundler if its own checks pass and it has deposited funds. Sponsorship can be revoked, emptied, or used as a censor. It is not a protocol right.
Model
What has to hold
The EntryPoint used by the account is the contract the holder meant. A fake entry point can pass a wallet's user interface and fail the user.
04 Simulation has rules
Observation
What the study says
Bundlers simulate validation before including an operation. The specification restricts what validation may read, so a sender cannot make the simulation succeed and the execution fail in a way that wastes the bundler. Those restrictions are the spec. Ignoring them makes the mempool griefable.
Model
What has to hold
Bundlers exist and find the operation. There is no protocol guarantee that the alt mempool is dense.
Falsifier
What would retire it
What does validation actually accept?
03 Sequence
One action, as an operating tape
- 01An account contract is deployed, with a validation function and an execution function.
- 02The holder builds a UserOperation describing the call they want.
- 03A bundler simulates validation and, if it likes the fee, includes the operation in a bundle.
- 04The EntryPoint contract runs validation, then execution, and pays the bundler from the account or the paymaster.
- 05If validation fails on chain, the bundler should not have included it. If execution fails after validation, the fee rules in the spec decide who eats the gas.
04 Load-bearing
The argument, and where a pitch drops it
Account abstraction here is a market structure
The cut
The protocol did not grow a new transaction type. A new set of intermediaries, the bundlers and paymasters, appeared. They can offer better wallets and they can reorder, refuse, or sponsor selectively. The MEV question moves up a layer. It does not close.
Why it carries weight
If this cut is skipped, the paper's name is being used without the mechanism that makes the name mean anything.
Where it is dropped
A paymaster can refuse, censor, or be empty. Sponsored gas is not a right.
Recovery is not included
The cut
A contract account can implement social recovery or a guardian. The EIP does not require one. An account with a single key and custom validation can be just as final, when the key is lost, as an externally owned account. The flexibility is also the footgun.
Why it carries weight
If this cut is skipped, the paper's name is being used without the mechanism that makes the name mean anything.
Where it is dropped
Custom validation can lock the owner out. Recovery is a policy the account must include. The EIP does not supply one.
05 Register
What has to be true
Model · Not re-measured
The EntryPoint used by the account is the contract the holder meant. A fake entry point can pass a wallet's user interface and fail the user.
Model · Not re-measured
Bundlers exist and find the operation. There is no protocol guarantee that the alt mempool is dense.
Model · Not re-measured
Validation follows the spec's restrictions if the holder cares about being included by ordinary bundlers.
Model · Not re-measured
Paymaster deposits are solvent if gas is supposed to be sponsored. An empty deposit fails the operation.
06 Divergence
What happened after the paper
Smart-contract wallets on Ethereum largely converged on this ERC rather than on a consensus change. Passkeys, session keys, and agent allowances are application policies on top of the UserOperation. The EIP is the citation for the alt mempool and the EntryPoint. It is not a citation for any particular wallet's recovery story, and it does not by itself authorise an agent to spend.
A later client, parameter set, or reward formula is a different object. Cite this paper for the mechanism. Cite a primary release for the network. This desk has not re-run the proof.
07 Pre-mortem
What to check before you use the idea
- 0 of 4 marked on this browser. A mark is a reading note, not a pass, a rating, or a recommendation.
08 Anatomy
The paper, in the order a builder needs
The problem it names
Protocol-level account abstraction means changing what a transaction is. ERC-4337 tries to get custom validation, batching, and sponsored gas by adding a contract and a mempool above the protocol.
What the design proposes
- A UserOperation carries the sender, the call, and the signature-like data the account expects.
- Bundlers simulate validation, then submit a bundle to the EntryPoint contract.
- A paymaster can cover gas if it deposits and if its own validation agrees.
How the mechanism is specified
- Validation must not depend on state that the bundler cannot safely simulate. The spec's rules exist so a bundle cannot be griefed after simulation.
- The EntryPoint is shared infrastructure. A bug there touches every account that uses it.
- The account's validation function defines what 'signature' means. It can be a passkey, a multisig, or a mistake.
What this page does not treat as proven
- This is not consensus account abstraction. A node does not have to understand UserOperations.
- A paymaster can refuse, censor, or be empty. Sponsored gas is not a right.
- Custom validation can lock the owner out. Recovery is a policy the account must include. The EIP does not supply one.
Why the desk still reads it
An agent wallet or a passkey account on Ethereum is usually this shape. Ask who validates, who bundles, who pays gas, and what happens if the EntryPoint or the paymaster stops.
09 Lexicon
Terms, opened into the record
- UserOperation
- The object a contract account submits, describing the call and the data that should validate it.
- Bundler
- A node that packs UserOperations into an ordinary transaction and is paid for the gas.
10 Repository
Every linked record on this page
Underlined words open a page that already exists: a concept, a protocol profile, a failure record, or another paper. If a word is not underlined, this desk does not have a record for it.
This is Blockchain Lab's reading of a public design paper. It is not the paper, not a copy of it, and not an offer of tokens, equity, custody or a partnership. Later network behaviour can diverge from the text. Nothing here is investment, legal or technical advice.
Research status: Design paper. Last reviewed: 1 October 2026. This is a reading of a public paper, not investment, legal or security advice.