The paymaster contract address is specified in the first 20 bytes of paymasterAndData.

The paymaster’s validatePaymasterUserOp function has rejected the user operation’s signature.

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Resolution Checklist

  1. For Custom Paymaster Contracts:

    • Verify correct signing of the user operation
    • Ensure proper encoding of the paymaster signature in paymasterAndData
    • Confirm correct computation of the custom operation hash
    • Review the signature verification logic in your paymaster

  2. For Third-Party Paymaster Services (e.g., JiffyLabs):

    • Avoid modifying user operation fields after paymaster signing (except signature)
    • If unmodified but still encountering errors, contact their support

  3. Advanced Troubleshooting:

    • Employ Tenderly or similar tools to investigate validatePaymasterUserOp behavior
AA33: Paymaster Validation Function FailureAA40: Verification Gas Limit Exceeded