Encyclopedia Ethereum · Entry 128
Smart-account bundlers: turning user operations into transactions
In this article
At a glance
Key facts
| Fact | Detail | Source |
|---|---|---|
| Object | A user operation is distinct from the bundler’s enclosing network transaction. | [1] |
| Validation | The account validates its requested operation through the EntryPoint flow. | [1] |
| Payment | Accounts or paymasters must cover the operation’s applicable gas costs. | [1] |
Separate the user request from its carrier
A wallet constructs a user operation containing the account’s requested execution and validation data. A bundler evaluates whether it can safely include the operation and packages accepted work into a transaction.
The user-operation identifier and the enclosing transaction hash serve different tracking purposes. A wallet should expose enough information to follow actual inclusion.
Validation protects the submission process
Bundlers simulate validation and apply the specified rules to reduce the risk of submitting operations that cannot pay or cannot be processed. The rules include constraints beyond an ordinary method-call preview.
Passing a bundler’s checks does not mean the user’s requested business action is sensible or that future state cannot change. Account authorization and economic outcome remain separate.
A bundler can decline or delay an operation
Bundlers choose what to submit within their software and fee policies. Their availability and willingness affect the route from signed request to block inclusion.
Use the relevant EntryPoint version and account implementation when interpreting an operation. The standard describes the protocol flow; deployed account stacks can use different EntryPoint versions and account rules.
Direct answers
Questions people ask
Does a bundler need to know my private key?
The protocol flow uses the account’s signed or otherwise authorized operation, not disclosure of its private signing key. The account implementation determines acceptable authorization.
Inspect the evidence
The answer and key facts have stable claim links. These records retain the scope and qualification when reused.
In ERC-4337, a bundler collects user operations and submits an Ethereum transaction that invokes the EntryPoint to process them. The account’s validation logic authorizes each operation. A bundler is an execution-submission participant, not a guarantee of inclusion or a replacement for the account’s signing and permission rules.
Scope: Ethereum · data through 2026-10-02. Verification: verified · 2026-10-02T18:12:41.505Z.
Link to this claimObject: A user operation is distinct from the bundler’s enclosing network transaction.
Scope: Ethereum · data through 2026-10-02. Verification: verified · 2026-10-02T18:12:41.505Z.
Link to this claimValidation: The account validates its requested operation through the EntryPoint flow.
Scope: Ethereum · data through 2026-10-02. Verification: verified · 2026-10-02T18:12:41.505Z.
Link to this claimPayment: Accounts or paymasters must cover the operation’s applicable gas costs.
Scope: Ethereum · data through 2026-10-02. Verification: verified · 2026-10-02T18:12:41.505Z.
Link to this claimRevision history
- — First publication after primary-source research and independent automated verification.
Source register
Sources and references
Retrieval dates and locators are recorded individually.- Account Abstraction Using Alt MempoolEthereum Improvement Proposals
User operations, bundler transaction submission and paymaster validation.
Locator: Specification; Bundlers; Paymasters; Security Considerations · Version / scope: EIP/ERC-4337; retrieved document hash recorded · Retrieved: 2026-10-02T17:03:42.486ZOpen source
Research and drafting use AI assistance. A separate automated review checks claims against primary sources; no external expert or named human review is implied. Publication, substantive editing, source retrieval and verification are recorded separately. This version was independently checked by an automated reviewer on 2 October 2026.
Editorial method and correctionsDegrees of Satoshi editorial project. “Smart-account bundlers: turning user operations into transactions.” Published 2026-10-02; updated 2026-10-02. https://degreesofsatoshi.com/encyclopedia/smart-account-bundlers/