# eth\_getStorageAt

The `eth_getStorageAt` command is used to obtain a value related to a storage position at the specified address, returning the exact state of the contract’s storage, which can’t be exposed by regular contract methods.

### Parameters

* `DATA`, 20 Bytes - address of the storage.
* `QUANTITY` - integer of the position in the storage.
* `QUANTITY|TAG` - integer block number, or the string "latest", "earliest" or "pending", see the [default block parameter](https://eth.wiki/json-rpc/API#the-default-block-parameter).

### Returns

* `DATA` - the value at this storage position.

### Example Request and Result for `eth_getStorageAt`

Calculating the correct position depends on the storage to retrieve. Consider the following contract deployed at `0x295a70b2de5e3953354a6a8344e616ed314d7251` by address `0x391694e7e0b0cce554cb130d723a9d27458f9298`.

```javascript
contract Storage {
    uint pos0;
    mapping(address => uint) pos1;

    function Storage() {
        pos0 = 1234;
        pos1[msg.sender] = 5678;
    }
}
```

**Retrieving the value of `pos0` is straight forward:**

Request

```
curl https://rpc-mainnet.u2u.xyz \
-X POST \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0", "method": "eth_getStorageAt", "params": ["0x295a70b2de5e3953354a6a8344e616ed314d7251", "0x0", "latest"], "id": 1}'
```

Result

```javascript
{
    "jsonrpc":"2.0",
    "id":1,
    "result":"0x00000000000000000000000000000000000000000000000000000000000004d2"
}
```

**Retrieving an element of the map is harder. The position of an element in the map is calculated with:**

```javascript
keccack(LeftPad32(key, 0), LeftPad32(map position, 0))
```

This means to retrieve the storage on `pos1[“0x391694e7e0b0cce554cb130d723a9d27458f9298”]` we need to calculate the position with:

```javascript
keccak(decodeHex("000000000000000000000000391694e7e0b0cce554cb130d723a9d27458f9298" + "0000000000000000000000000000000000000000000000000000000000000001"))
```

**The geth console which comes with the web3 library can be used to make the calculation:**

```bash
> var key = "000000000000000000000000391694e7e0b0cce554cb130d723a9d27458f9298" + "0000000000000000000000000000000000000000000000000000000000000001"
undefined
> web3.sha3(key, {"encoding": "hex"})
"0x6661e9d6d8b923d5bbaab1b96e1dd51ff6ea2a93520fdc9eb75d059238b8c5e9"
```

**Now to fetch the storage:**

Request

```
curl https://eth-mainnet.blastapi.io/<id> \
-X POST \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0", "method": "eth_getStorageAt", "params": ["0x295a70b2de5e3953354a6a8344e616ed314d7251", "0x6661e9d6d8b923d5bbaab1b96e1dd51ff6ea2a93520fdc9eb75d059238b8c5e9", "latest"], "id": 1}'
```

Result

```javascript
{
    "jsonrpc":"2.0",
    "id":1,
    "result":"0x000000000000000000000000000000000000000000000000000000000000162e"
}
```