---
description: Starts recording all storage reads and writes
---

## `record`

### Signature

```solidity
function record() external;
```

### Description

Tells the VM to start recording all storage reads and writes. To access the recorded data, use [`accesses`](/reference/cheatcodes/accesses).

### Examples

:::code-group

```solidity [test/Record.t.sol]
function testRecord() public {
    vm.record();
    numsContract.num2(); // reads slot 1
    
    (bytes32[] memory reads, bytes32[] memory writes) = vm.accesses(
        address(numsContract)
    );
    
    assertEq(uint256(reads[0]), 1); // slot 1 was read
    assertEq(writes.length, 0);     // no writes occurred
}
```

```solidity [src/NumsContract.sol]
contract NumsContract {
    uint256 public num1 = 100; // slot 0
    uint256 public num2 = 200; // slot 1
}
```

:::

### Gotchas

:::note
Every write also counts as an additional read. If you write to a slot, it will appear in both the `reads` and `writes` arrays.
:::

### Related Cheatcodes

- [`accesses`](/reference/cheatcodes/accesses) - Gets recorded storage reads and writes

### See Also

- [Std Storage](/reference/forge-std/std-storage) - High-level storage manipulation library
