> ## Documentation Index
> Fetch the complete documentation index at: https://vowena-dependabot-github-actions-actions-checkout-7.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# extend_ttl

> Extends the time-to-live of plan and subscription storage entries on the Soroban ledger, preventing them from being archived and ensuring data availability.

```rust theme={null}
fn extend_ttl(env: Env, plan_id: u64, sub_id: u64)
```

Extends the TTL (time-to-live) of plan and subscription persistent storage entries. This prevents these entries from being archived by the Soroban ledger when their TTL expires.

<Note>
  Soroban persistent storage entries have a finite TTL. When the TTL expires,
  the entry is **archived** - it still exists but cannot be accessed until
  restored. Calling `extend_ttl` refreshes the TTL window, keeping the data
  accessible. This is critical for long-running subscriptions that span months
  or years.
</Note>

***

## Parameters

| Name      | Type  | Description                              |
| --------- | ----- | ---------------------------------------- |
| `plan_id` | `u64` | The plan ID whose TTL to extend.         |
| `sub_id`  | `u64` | The subscription ID whose TTL to extend. |

***

## Authorization

None. Anyone can extend the TTL of any entry. This is safe because extending TTL only keeps data accessible longer - it does not modify the data.

***

## Return value

None (`void`).

***

## Events emitted

None.

***

## Error cases

None. If the plan or subscription does not exist, the function is a no-op.

***

## Examples

<Tabs>
  <Tab title="SDK">
    ```typescript theme={null}
    import { VowenaClient, NETWORKS } from "@vowena/sdk";

    const client = new VowenaClient({
      contractId: NETWORKS.testnet.contractId,
      rpcUrl: NETWORKS.testnet.rpcUrl,
      networkPassphrase: NETWORKS.testnet.networkPassphrase,
    });

    // Extend TTL for plan 1 and subscription 5
    const tx = await client.buildExtendTtl(
      1,   // Plan ID
      5    // Subscription ID
    );

    const signedXdr = await signTransaction(tx);
    await client.submitTransaction(signedXdr);
    ```
  </Tab>

  <Tab title="Soroban CLI">
    ```bash theme={null}
    soroban contract invoke \
      --id CONTRACT_ID \
      --network testnet \
      --source ANY_SECRET_KEY \
      -- \
      extend_ttl \
      --plan_id 1 \
      --sub_id 5
    ```
  </Tab>
</Tabs>

<AccordionGroup>
  <Accordion title="Why does TTL matter?">
    On Soroban, every piece of persistent data has a TTL measured in ledger sequence numbers. When the current ledger passes the entry's TTL, the entry is archived. Archived entries cannot be read or written until they are restored (which costs additional fees).

    For Vowena, this means a subscription that hasn't been touched in several months could become inaccessible. The `extend_ttl` function prevents this by refreshing the TTL window.
  </Accordion>

  <Accordion title="Who should call extend_ttl?">
    Typically, keeper bots or the merchant's backend should periodically call `extend_ttl` for active plans and subscriptions. The Vowena Dashboard keeper service handles this automatically.

    Since the function is permissionless, anyone can extend TTL for any entry - there is no access control needed because extending TTL only keeps data alive longer.
  </Accordion>

  <Accordion title="What are the TTL thresholds?">
    Vowena uses these default TTL policies:

    * **Instance storage** (admin, counters): \~30 day threshold, \~90 day extend
    * **Persistent storage** (plans, subscriptions, indexes): \~30 day threshold, \~120 day extend

    The `extend_ttl` function refreshes persistent entries to the \~120 day extend window.
  </Accordion>
</AccordionGroup>