> ## Documentation Index
> Fetch the complete documentation index at: https://jiffyscan.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# AA50: Paymaster PostOp Reversion

> Addressing issues with paymaster's postOp function

<Note>
  The `postOp` function is called by the EntryPoint on the paymaster contract after user operation execution, often used for additional accounting logic.
</Note>

The paymaster contract's `postOp` function has reverted unexpectedly.

## Resolution Strategies

1. For Custom Paymaster Contracts:
   * Review and correct the `postOp` function implementation
   * If not using `postOp`, ensure the `context` parameter is not set in `validatePaymasterUserOp`

2. For Third-Party Paymaster Services:
   * If using a service like JiffyLabs and encountering this error, [contact their support](https://t.me/JiffyScan)

3. Advanced Troubleshooting:
   * Investigate `postOp` reversion causes using tools like [Tenderly](https://tenderly.co/)