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# Transactions Updater

The `Updater` hook will automatically check the status of each pending transaction based on the logic provided in `shouldCheck`. It will use the provided callbacks to inform the rest of the app about the status of each transaction, allowing the state to be accurately updated.

```typescript
export function shouldCheck(lastBlockNumber: number, tx: Transaction): boolean {
  if (tx.receipt) return false;
  if (!tx.lastCheckedBlockNumber) return true;
  const blocksSinceCheck = lastBlockNumber - tx.lastCheckedBlockNumber;
  if (blocksSinceCheck < 1) return false;
  const minutesPending = (new Date().getTime() - tx.addedTime) / 60_000;
  if (minutesPending > 60) {
    // every 10 blocks if pending longer than an hour
    return blocksSinceCheck > 9;
  } else if (minutesPending > 5) {
    // every 3 blocks if pending longer than 5 minutes
    return blocksSinceCheck > 2;
  } else {
    // otherwise every block
    return true;
  }
}
```

### **Updater Hook**

```typescript
export default function Updater({
  pendingTransactions,
  onCheck,
  onReceipt,
}: UpdaterProps): null {
...
}
```

**Props**

* `pendingTransactions`: An object mapping transaction hashes to their metadata, including added time and last checked block number.
* `onCheck`: A callback function invoked for transactions that have been checked but not yet confirmed. It receives an object with the transaction's `chainId`, `hash`, and the `blockNumber` it was last checked against. Dispatches the `checkedTransaction` action when a transaction check is triggered
* `onReceipt`: A callback function invoked for transactions once they're confirmed. It receives an object with the transaction's `chainId`, `hash`, and its `receipt`. Dispatches the `finalizeTransaction` action to store the final state of the transaction in the Redux store.