> ## Documentation Index
> Fetch the complete documentation index at: https://optimism-373f39ad-feat-swap-documentation.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# op-reth historical proof configuration

> Configuration options for historical proofs using ExEx in op-reth (op-rs fork).

This page provides documentation for the configuration options available in [op-reth](https://github.com/ethereum-optimism/optimism/tree/develop/rust/op-reth) for supporting historical proofs via ExEx.

By enabling this Execution Extension (ExEx), the node initializes a separate storage database specifically for historical trie nodes. This allows the node to **generate and serve historical proofs** efficiently, which is critical for applications requiring historical state access, such as fault proof systems.

For a complete setup guide, see the tutorial on [Running op-reth with Historical Proofs](/node-operators/tutorials/reth-historical-proofs).

<Info>
  This fork inherits all standard op-reth configuration options. See the [op-reth configuration reference](/node-operators/reference/op-reth-config).
</Info>

## Proof History

Options for configuring the proof history ExEx.

### proofs-history

If true, initialize external-proofs exex to save and serve trie nodes to provide proofs faster.

<Tabs>
  <Tab title="Syntax">`--proofs-history`</Tab>
</Tabs>

### proofs-history.storage-path

The path to the storage DB for proofs history.

<Tabs>
  <Tab title="Syntax">`--proofs-history.storage-path <PROOFS_HISTORY_STORAGE_PATH>`</Tab>
</Tabs>

### proofs-history.window

The window to span blocks for proofs history. Value is the number of blocks.
Default is 1 month of blocks based on 2 seconds block time (`30 * 24 * 60 * 60 / 2 = 1,296,000`).

<Tabs>
  <Tab title="Syntax">`--proofs-history.window <PROOFS_HISTORY_WINDOW>`</Tab>
  <Tab title="Default">`1296000`</Tab>
</Tabs>

### proofs-history.prune-interval

Interval between proof-storage prune runs. Accepts human-friendly durations like "100s", "5m", "1h".

* Shorter intervals prune smaller batches more often.
* Longer intervals prune larger batches less often.

A shorter interval is preferred so that prune runs stay small and don’t stall writes for too long.

<Tabs>
  <Tab title="Syntax">`--proofs-history.prune-interval <PROOFS_HISTORY_PRUNE_INTERVAL>`</Tab>
  <Tab title="Default">`15s`</Tab>
</Tabs>

### proofs-history.verification-interval

Verification interval: perform full block execution every N blocks for data integrity.

* `0`: Disabled (Default). Always use fast path with pre-computed data.
* `1`: Always verify. Always execute blocks.
* `N`: Verify every Nth block (e.g., 100 = every 100 blocks).

Periodic verification helps catch data corruption while maintaining good performance.

<Tabs>
  <Tab title="Syntax">`--proofs-history.verification-interval <PROOFS_HISTORY_VERIFICATION_INTERVAL>`</Tab>
  <Tab title="Default">`0`</Tab>
</Tabs>

## Management Commands

The `op-reth proofs` command allows you to manage the storage of historical proofs.

### init

Initialize the proofs storage with the current state of the chain.

```bash theme={null}
op-reth proofs init --chain <CHAIN> --datadir <DATA_DIR> --proofs-history.storage-path <PROOFS_HISTORY_STORAGE_PATH> 
```

### prune

Prune old proof history to reclaim space.

```bash theme={null}
op-reth proofs prune --chain <CHAIN> --datadir <DATA_DIR> --proofs-history.storage-path <PROOFS_HISTORY_STORAGE_PATH> --proofs-history.window <PROOFS_HISTORY_WINDOW>
```

### unwind

Unwind the proofs storage to a specific block

```bash theme={null}
op-reth proofs unwind --datadir <DATA_DIR> --proofs-history.storage-path <PROOFS_HISTORY_STORAGE_PATH> --target <TARGET_BLOCK>
```