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

# CheckIfTransactionIsExpired

> Check whether a compiled transaction's blockhash has expired.

Checks if a compiled transaction's `recent_blockhash` has aged out. Solana transactions expire approximately 150 slots (\~2 minutes on mainnet) after their blockhash was created. An expired transaction cannot be submitted — it must be recompiled.

<Note>
  If `is_expired` is true, call [CompileTransaction](/api-reference/transaction/compile-transaction) again to get a fresh blockhash.
  Expiry cannot be recovered — the existing compiled transaction bytes must be discarded.
</Note>

## Request

<ResponseField name="transaction" type="Transaction (object)" required>
  Transaction to check (must be in COMPILED or later state).
</ResponseField>

<ResponseField name="commitment_level" type="CommitmentLevel (enum)">
  Optional. Commitment level for blockhash freshness check. Defaults to CONFIRMED.
</ResponseField>

<Info>
  **commitment\_level** is optional. When omitted or set to `COMMITMENT_LEVEL_UNSPECIFIED`, the service defaults to `COMMITMENT_LEVEL_CONFIRMED`. See [CommitmentLevel](/api-reference/shared-types#commitmentlevel) for trade-offs between processed, confirmed, and finalized.
</Info>

## Response

<ResponseField name="is_expired" type="bool">
  True if the transaction's blockhash has expired and the transaction must be recompiled before submission. False if the blockhash is still fresh.
</ResponseField>

## Code Examples

<CodeGroup>
  ```go Go theme={null}
  resp, err := client.CheckIfTransactionIsExpired(ctx, &transaction_v1.CheckIfTransactionIsExpiredRequest{
      Transaction: compiledTxn,
  })
  if err != nil {
      log.Fatal(err)
  }
  if resp.IsExpired {
      fmt.Println("Transaction expired — recompile required")
      // call CompileTransaction again
  }
  ```

  ```rust Rust theme={null}
  let response = client.check_if_transaction_is_expired(tonic::Request::new(
      CheckIfTransactionIsExpiredRequest {
          transaction: Some(compiled_txn),
          ..Default::default()
      }
  )).await?;
  if response.into_inner().is_expired {
      println!("Transaction expired — recompile required");
  }
  ```

  ```typescript TypeScript theme={null}
  const req = new CheckIfTransactionIsExpiredRequest();
  req.setTransaction(compiledTxn);
  client.checkIfTransactionIsExpired(req, (err, response) => {
    if (response.getIsExpired()) {
      console.log("Transaction expired — recompile required");
    }
  });
  ```
</CodeGroup>