EntryPoint

This page documents the on-chain interface of the EntryPoint deployed on BOT Chain. When submitting UserOperations directly, the caller must assume the responsibilities of a Bundler.

1. PackedUserOperation

EntryPoint accepts the following on-chain structure:

struct PackedUserOperation {
    address sender;
    uint256 nonce;
    bytes initCode;
    bytes callData;
    bytes32 accountGasLimits;
    uint256 preVerificationGas;
    bytes32 gasFees;
    bytes paymasterAndData;
    bytes signature;
}

1.1 Fields and encoding

Field	Meaning	Encoding layout
sender	Smart-account address	smartAccount(160)
nonce	Two-dimensional nonce managed by EntryPoint	key(192) ‖ sequence(64)
initCode	Factory address and calldata used for first deployment	Undeployed: factory(160) ‖ factoryData(N); deployed: 0x
callData	Execution data sent to the smart account	selector(32) ‖ encodedArguments(N)
accountGasLimits	Gas limits for account validation and execution	verificationGasLimit(128) ‖ callGasLimit(128)
preVerificationGas	Calldata and bundle overhead outside on-chain validation	preVerificationGas(256)
gasFees	EIP-1559 priority fee and maximum total fee	maxPriorityFeePerGas(128) ‖ maxFeePerGas(128)
paymasterAndData	Optional Paymaster address, Gas limits, and custom data	Used: paymaster(160) ‖ paymasterVerificationGasLimit(128) ‖ paymasterPostOpGasLimit(128) ‖ paymasterData(N); unused: 0x
signature	Authorization data validated by the smart account	accountSignature(N)

Numbers in parentheses are bit lengths; N denotes a variable length.

2. Execution interfaces

function handleOps(
    PackedUserOperation[] calldata ops,
    address payable beneficiary
) external;

function handleAggregatedOps(
    UserOpsPerAggregator[] calldata opsPerAggregator,
    address payable beneficiary
) external;

2.1 handleOps

Parameter	Description
ops	UserOperations that do not use a signature aggregator
beneficiary	Address that receives the actual Gas fees for the batch

EntryPoint validates the entire batch before executing each account's callData. A validation error can revert the entire batch. A business-execution revert is recorded through an event and does not necessarily revert the outer transaction.

2.2 handleAggregatedOps

Use this method when accounts return a non-zero signature aggregator. UserOperations are grouped by aggregator, and each group carries an aggregated signature. Use handleOps when signature aggregation is not required.

UserOpsPerAggregator contains:

Field	Type	Description
userOps	PackedUserOperation[]	Operations handled by the current aggregator
aggregator	IAggregator	Aggregator for the group; only in handleAggregatedOps, a zero-address group means that no aggregation is needed
signature	bytes	Aggregated signature for the group

3. Hash, nonce, and address

function getUserOpHash(
    PackedUserOperation calldata userOp
) external view returns (bytes32);

function getNonce(
    address sender,
    uint192 key
) external view returns (uint256 nonce);

function incrementNonce(uint192 key) external;

function getSenderAddress(bytes memory initCode) external;

3.1 getUserOpHash

Returns the UserOperation hash that the account must validate. The hash binds:

• UserOperation content, excluding signature
• Current EntryPoint address
• Current chainId

Changing any participating field after signing invalidates the signature.

3.2 getNonce

Returns the next complete nonce for an account and nonce key:

nonce = uint192 key || uint64 sequence

SimpleAccount uses key 0 by default. Do not substitute the Owner EOA transaction nonce or the smart account's eth_getTransactionCount.

3.3 incrementNonce

Allows a caller to advance the sequence for one of its nonce keys. Standard accounts usually rely on EntryPoint to update the nonce after successful validation.

3.4 getSenderAddress

Calculates a counterfactual account address from initCode. The method always reverts and returns the result through the custom error SenderAddressResult(address sender).

4. Deposit and stake

function getDepositInfo(
    address account
) external view returns (DepositInfo memory info);

function balanceOf(address account)
    external view returns (uint256);

function depositTo(address account) external payable;

function withdrawTo(
    address payable withdrawAddress,
    uint256 withdrawAmount
) external;

function addStake(uint32 unstakeDelaySec) external payable;

function unlockStake() external;

function withdrawStake(
    address payable withdrawAddress
) external;

4.1 Deposit

A deposit is the balance that an account or Paymaster pre-funds in EntryPoint to pay UserOperation Gas.

Method	Description
balanceOf	Queries an entity's deposit
getDepositInfo	Queries deposit, stake, and unlock state together
depositTo	Allows any address to fund the specified entity
withdrawTo	Withdraws the caller's own deposit

4.2 Stake

A stake is locked by a Factory, Paymaster, or aggregator to satisfy validation and reputation rules. It is not used directly to pay UserOperation Gas.

Method	Description
addStake	Adds stake and sets a minimum unlock delay
unlockStake	Begins the unlock waiting period
withdrawStake	Withdraws the stake after the waiting period

Deposit and stake are independent. A stake alone cannot pay Gas, and a deposit alone does not necessarily satisfy the Bundler's stake requirement for entities that access restricted storage.

5. Core events

Event	Key fields	Purpose
UserOperationEvent	userOpHash, sender, paymaster, nonce, success, actualGasCost, actualGasUsed	Determines the final result of each UserOperation
AccountDeployed	userOpHash, sender, factory, paymaster	Records counterfactual account deployment
UserOperationRevertReason	userOpHash, sender, nonce, revertReason	Records revert data from the account's business call
PostOpRevertReason	userOpHash, sender, nonce, revertReason	Records a Paymaster postOp revert
UserOperationPrefundTooLow	userOpHash, sender, nonce	Records insufficient prefund during execution
BeforeExecution	None	Separates validation-stage and execution-stage events
Deposited / Withdrawn	account, amount	Records deposit changes
StakeLocked / StakeUnlocked / StakeWithdrawn	account, stake, time	Records the stake lifecycle

A successful outer handleOps transaction does not mean that every UserOperation succeeded. Use UserOperationEvent.success as the result.

6. Core errors

Error	Description
FailedOp(opIndex, reason)	The specified UserOperation failed during validation or prefunding
FailedOpWithRevert(opIndex, reason, inner)	Failure with internal revert data from an account, Factory, or Paymaster
PostOpReverted(returnData)	Paymaster postOp reverted
SignatureValidationFailed(aggregator)	Aggregated signature validation failed
SenderAddressResult(sender)	Expected result carrier for getSenderAddress