Bundler Errors

This page documents common errors you may encounter when using the bundler, including both bundler-specific errors and EntryPoint errors.

Bundler Error Codes (EIP-7769)

The bundler implements the EIP-7769 specification which standardizes ERC-4337 bundler error codes.

EntryPoint Errors

These errors originate from the EntryPoint contract during UserOperation validation or execution.

Account Errors (AA1x)

AA10: sender already constructed

The account at the sender address already exists, but the UserOperation includes initialization code.

• Remove the initCode (v0.6) or factory/factoryData (v0.8+) fields if the account is already deployed
• Verify you're using the correct sender address

AA13: initCode failed or OOG

The initialization code failed to execute or ran out of gas.

• Increase the verificationGasLimit
• Verify your initCode or factoryData is correct
• Check that the factory contract is deployed on this chain

AA14: initCode must return sender

The factory's initialization code did not return the expected sender address.

• Verify the sender address matches what your factory will deploy
• Check your factory contract implementation

AA15: initCode must create sender

The initialization code executed but didn't create a contract at the sender address.

• Verify the factory contract deploys to the expected address
• Check for issues in your account deployment logic

Account Validation Errors (AA2x)

AA20: account not deployed

The sender account does not exist and no initialization code was provided.

• Include initCode (v0.6) or factory/factoryData (v0.8+) to deploy the account
• Verify the sender address is correct

AA21: didn't pay prefund

The account doesn't have enough native tokens to cover gas costs (when not using a paymaster).

• Fund the sender address with native tokens
• Use a paymaster to sponsor the transaction

AA22: expired or not due

The UserOperation's validity time window has passed or hasn't started yet.

• Check the account's validation time constraints
• Submit the operation within the valid time window

AA23: reverted

The account's validation function reverted.

• Check your account contract's validateUserOp implementation
• Verify the signature is valid
• Ensure the account has proper permissions

AA24: signature error

The signature verification failed.

• Verify the signature is correctly formatted
• Ensure you're signing the correct UserOperation hash
• Check the signer has permission on the account

AA25: invalid account nonce

The nonce is invalid (already used or incorrect key).

• Get the current nonce from the EntryPoint contract
• Ensure you're using the correct nonce key for parallel operations

Paymaster Errors (AA3x)

AA30: paymaster not deployed

The paymaster contract specified in the UserOperation is not deployed.

• Verify the paymaster address is correct
• Check that the paymaster is deployed on this chain

AA31: paymaster deposit too low

The paymaster doesn't have enough funds deposited in the EntryPoint.

• Contact your paymaster provider
• If self-hosted, deposit more funds via the paymaster's deposit() function

AA32: paymaster expired or not due

The paymaster signature has expired or isn't valid yet.

• Request fresh paymaster data
• Check the paymaster's time validity window

AA33: reverted

The paymaster's validation function reverted.

• Contact your paymaster provider
• Verify the UserOperation meets the paymaster's sponsorship criteria

AA34: signature error

The paymaster's signature verification failed.

• Request fresh paymaster data
• Verify the paymaster data hasn't been tampered with

Gas Errors (AA4x)

AA40: over verificationGasLimit

The verification phase used more gas than allocated.

• Increase verificationGasLimit
• Re-estimate gas using eth_estimateUserOperationGas

AA41: too little verificationGas

The verificationGasLimit is set too low for the operation.

• Increase verificationGasLimit
• Use eth_estimateUserOperationGas to get accurate estimates

Post-Operation Errors (AA5x)

AA50: postOp reverted

The paymaster's postOp function reverted.

• Contact your paymaster provider
• Increase paymasterPostOpGasLimit if using v0.8+

AA51: prefund below actualGasCost

The actual gas cost exceeded what was prefunded.

• Increase gas limits
• Ensure sufficient funds or paymaster coverage

Internal Errors (AA9x)

AA90: invalid beneficiary

The bundler specified an invalid beneficiary address.

• This is a bundler configuration error; contact support

AA91: failed send to beneficiary

Failed to send funds to the bundler's beneficiary address.

• This is typically a bundler infrastructure issue; contact support

AA92: internal call only

An external call was made to an internal EntryPoint function.

• Ensure your code isn't directly calling internal EntryPoint methods

AA93: invalid paymasterAndData

The paymasterAndData field is malformed.

• Verify the paymaster data format (first 20 bytes must be paymaster address)
• Request fresh paymaster data

AA94: gas values overflow

Gas values caused an arithmetic overflow.

• Reduce gas limit values
• Use reasonable gas estimates

AA95: out of gas

The operation ran out of gas during execution.

• Increase callGasLimit
• Optimize your transaction's gas usage

AA96: invalid aggregator

An invalid signature aggregator was specified.

• Verify the aggregator contract address
• Ensure the aggregator is properly registered