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

# How to rewind op-geth

> Learn how to rewind an op-geth node to a previous chain head.

## Overview

This tutorial teaches you how to rewind a single op-geth instance to a previous chain head.
This can be helpful to fix a divergent node, recreate archival state, or the safedb from an earlier chain state.

## Rewind op-geth

Follow these steps to rewind your op-geth node.

<Steps>
  <Step title="Shut down the CL">
    Whatever CL clients are driving the op-geth instance need to be stopped to prevent them from interfering with the rewind later.
    This would typically be a locally running `op-node` or `kona-node` application, a Docker container or a pod in a Kubernetes cluster.

    <Note>
      Make sure you don't have something like ArgoCD syncing the app in question which would just scale the pod back up again.
    </Note>
  </Step>

  <Step title="Determine rewind target">
    If you already know the block number/hash you want to rewind to, you can proceed to the next step.

    If you only know the *timestamp* you want to rewind to, you can find the corresponding block with

    ```bash theme={null}
    cast find-block 1741890000 -r <ETH_RPC_URL>
    ```

    Where `<ETH_RPC_URL>` points to your op-geth node’s RPC endpoint, e.g. `http://localhost:8545` if it was a local instance with the default port and `1741890000` is an example unix timestamp. You can use e.g. [https://www.epochconverter.com/](https://www.epochconverter.com/) to convert from human times to unix timestamps.
  </Step>

  <Step title="Rewind op-geth">
    You need the JWT secret and *open* & *admin* port (default `8545` & `8551`).
    Then you can use the `op-wheel` command from the [monorepo](https://github.com/ethereum-optimism/optimism/tree/develop/op-wheel) to issue the rewind.

    ```bash theme={null}
    # save JWT secret to env var
    export JWT="YourJWTSecret123"
    # assuming default ports 8545 and 8551 and local endpoint
    go run ./op-wheel/cmd engine rewind \
    --engine.open http://localhost:8545 \
    --engine http://localhost:8551 \
    --engine.jwt-secret $JWT \
    --log.level DEBUG \
    --set-head --to 8460000
    ```

    This would rewind the op-geth node to the block with number `8460000`. You should have determined the right block number in step 2.
  </Step>

  <Step title="Start the CL">
    You can now start your CL client again. It will sync from the rewound block head.
  </Step>
</Steps>